Sequence distributions in free-radical polymers

This thesis is concerned with demonstrating how the visual representation of the sequence distribution of individual monomer units, of a polymer, that would be observed upon polymerisation, may be utilised in designing and synthesizing polymers with relatively low cell adhesion characteristics, The initial part of this thesis is concerned with demonstrating the use of a computer simulation technique, in illustrating the sequence distribution that would be observed upon the polymerisation of a set of monomers. The power of the computer simulation technique has been demonstrated through the simulation of the sequence distributions of some generic contact lens materials. These generic contact lens materials were chosen simply because in the field of biomaterials their compositions are amongst the most systematically regulated and they present a wide range of compositions. The validity of the computer simulation technique has been assessed through the synthesis and analysis of linear free-radical polymers at different conversions. Two main parameters were examined, that of composition and the number-average sequence lengths of individual monomer units, at various conversions. The polymers were synthesized through the solution polymerisation process. The monomer composition was determined by elemental analysis and 13C nuclear magnetic analysis (NMR). Number-average sequence lengths were determined exclusively through 13C NMR. Although the computer simulation technique provides a visual representation of the monomer sequence distribution up to 100% conversion, these assessments were made on linear polymers at a reasonably high conversion (above 50%) but below 100% conversion of ease for analysis. The analyses proved that the computer simulation technique was reasonably accurate in predicting the sequence distribution of monomer units, upon polymerisation, in the polymer.An approach has been presented which allows one to manipulate the use of monomers, with their reactivity ratios, thereby enabling us to design polymers with controlled sequence distributions.Hydrogel membranes, with relatively controlled sequence distributions and polymerised to 100% conversion, were synthesized to represent prospective biomaterials. Cell adhesion studies were used as a biological probe to investigate the susceptibility of the surface of these membranes to cell adhesion. This was necessary in order to assess the surface biocompatibility or biotolerance of these prospective biomaterials.

Living cationic polymerization of styrene monomers

This thesis describes an experimental investigation of synthesis of polystyrene under various polymerization conditions such as solvent polarity, temperature, initial concentrations of initiator, catalyst, monomer and added salts or co-catalyst, which was achieved using the living cationic polymerization technology in conjunction with gel permeation chromatography (GPC) and NMR spectroscopy. Polymerizations of styrene were conducted using 1-phenyl ethylchloride (1-PEC) as an initiator and tin tetrachloride (SnCI4) as a catalyst in the presence of tetra-n-Butylammonium chloride (nBu4NCI). Effects of solvent polarity varied by mixing dichloromethane (DCM) and less polar cyclohexane (C.hex), temperature, initial concentrations of SnC14, 1-PEC and nBu4NCI on the polymerizations were examined, and the conditions under which a living polymerization can be obtained were optimised as: [styrene]o ~ 0.75 - 2 M; [1-PEC]o ~ 0.005 - 0.05 M; [SnCI4Jo ~ 0.05 - 0.4 M; [nBu4NCIJo ~ 0.001 - 0.1 M; DCM/C.hex ~ 50/0 - 20/30 v/v; T ~ 0 to -45°C. Kinetic studies of styrene polymerization using the Omnifit sampling method showed that the number average molecular weight (Mn) of the polymers obtained increased in direct proportion to monomer conversion and agreed well with the theoretical Mn expected from the concentration ratios of monomer to initiator. The linearities of both the 1n([MJoI[M]) vs. time plot and the Mn vs. monomer conversion plot, and the narrow molecular weight distribution (MWD) measured using GPC demonstrated the livingness of the polymerizations, indicating the absence of irreversible termination and transfer within the lifetimes of the polymerizations. The proposed 'two species' propagation mechanism was found to apply for the styrene polymerization with 1-PEC/SnCI4 in the presence of nBu4NCl. The further kinetic experiments showed that living styrene polymerizations were achieved using the 1-PEC/SnCI4 initiating system in mixtures of DCM/C.hex 30/20 v/v at -15°C in the presence of various bromide salts, tetra-n-butylammonium bromide, tetra-n-pentylammonium bromide, tetra-n-heptylammonium bromide, and tetra-n-octylammonium bromide, respectively. The types of the bromide salts were found to have no significant effect on monomer conversion, Mn, polydispersity and initiation efficiency. Living polymerizations of styrene were also achieved using titanium tetrachloride (TiCI4) as a catalyst and 1-PEC as an initiator in the presence of a small amount of 2,6-di-tert-butylpyridine or pyridine instead of nBu4NCl. GPC analysis showed that the polymers obtained had narrow polydispersities (P.D. < 1.3), and the linearities of both the In([MJo/[MJ) vs. time plot and the Mn vs. monomer conversion plot demonstrated that the polymerizations are living, when the ratio of DCM and C.hex was less than 40 : 10 and the reaction temperature was not lower than -15°C. The reaction orders relative to TiCl4 and 1-PEC were estimated from the investigations into the rate of polymerization to be 2.56 and 1.0 respectively. lH and 13C NMR analysis of the resultant polystyrene would suggest the end-functionality of the product polymers is chlorine for all living polymerizations.

The production of the enzyme dextransucrase by batch and continuous fermentation techniques

A review of the literature of work carried out on dextransucrase production, purification, immobilization and reactions has been carried out. A brief review has also been made of the literature concerning general enzyme biotechnology and fermentation technology. Fed-batch fermentation of the bacteria Leuconostoc mesenteroides NRRL B512 (F) to produce dextransucrase has formed the major part of this research. Aerobic and anaerobic fermentations have been studied using a 16 litre New Brunswick fermenter which has a 3-12 litre working volume. The initial volume of broth used in the studies was 6 litres. The results of the fed-batch fermentations showed for the first time that yields of dextransucrase are much higher under the anaerobic conditions than during the aerobic fermentations. Dextransucrase containing 300-350 DSU/cm3 of enzyme activity has been obtained during the aerobic fermentations, while in the anaerobic fermentations, enzyme yields containing 450-500 DSU/cm3 have been obtained routinely. The type of yeast extract used in the fermentation medium has been found to have significant effects on enzyme yield. Of the different types studied, the Gistex Standard was found to be the type that favoured the highest enzyme production. Studies have also been carried out on the effect of agitation rate and antifoam on the enzyme production during the anaerobic experiments. Agitation rates of up to 600 rpm were found not to affect the enzyme yield, however, the presence of antifoam in the medium led to a significant reduction in enzyme activity (less than 300 DSU/cm3). Scale-up of the anaerobic fermentations has been performed at up to the 1000 litre level with enzyme yields containing more than 400 DSU/cm3 of activity being produced. Some of the enzyme produced at this scale was used for the first time to produce dextran on an industrial scale via the enzyme route, with up to 99% conversion of sucrose to dextran being obtained. An attempt has been made at continuous dextransucrase production. Cell washout was observed to occur at dilution rates of greater than 0.4 h-1. Dextransucrase containing up to 25 DSU/cm3/h has been produced continuously.

Application of SOA-NOLM in all-optical processing

This thesis presents experimental investigations of the use of semiconductor optical amplifiers in a nonlinear loop mirror (SOA-NOLM) and its application in all-optical processing. The techniques used are mainly experimental and are divided into three major applications. Initially the semiconductor optical amplifier, SOA, is experimentally characterised and the optimum operating condition is identified. An interferometric switch based on a Sagnac loop with the SOA as the nonlinear element is employed to realise all-optical switching. All-optical switching is a very attractive alternative to optoelectronic conversion because it avoids the conversion from the optical to the electronic domain and back again. The first major investigation involves a carrier suppressed return to zero, CSRZ, format conversion and transmission. This study is divided into single channel and four channel WDM respectively. The optical bandwidth which limits the conversion is investigated. The improvement of the nonlinear tolerance in the CSRZ transmission is shown which shows the suitability of this format for enhancing system performance. Second, a symmetrical switching window is studied in the SOA-NOLM where two similar control pulses are injected into the SOA from opposite directions. The switching window is symmetric when these two control pulses have the same power and arrive at the same time in the SOA. Finally, I study an all-optical circulating shift register with an inverter. The detailed behaviour of the blocks of zeros and ones has been analysed in terms of their transient measurement. Good agreement with a simple model of the shift register is obtained. The transient can be reduced but it will affect the extinction ratio of the pulses.

Applied pharmaceutical practice

Applied Pharmaceutical Practice is an invaluable resource and will guide the student pharmacist and pharmacy technician through the main stages involved in pharmaceutical dispensing. As a core reference text, it is ideal as a companion to the compulsory dispensing courses found in all undergraduate MPharm programmes and the equivalent technical training courses. Contents include: •medicines classification and standard operating procedures •NHS supply in the community and within hospitals •non-NHS supply •controlled drugs •emergency supply •patient counselling and communication •poisons and spirits This practical textbook contains useful exercises with an answers section and numerous examples and is written by authors with extensive experience within the field. This is a comprehensive guide through the main stages of pharmaceutical dispensing.The textbook is designed to guide student pharmacists or pharmacy technicians through the main stages involved in pharmaceutical dispensing. It provides students with a core reference text to accompany the compulsory dispensing course found in all pharmacy undergraduate programmes, highlighting and explaining all key concepts behind the processes involved in pharmaceutical dispensing.

Effect of preparation conditions on the formation of the active phase of carbon fiber catalytic systems for the low-temperature oxidation of carbon monoxide

We studied the effects of the composition of impregnating solution and heat treatment conditions on the activity of catalytic systems for the low-temperature oxidation of CO obtained by the impregnation of Busofit carbon-fiber cloth with aqueous solutions of palladium, copper, and iron salts. The formation of an active phase in the synthesized catalysts at different stages of their preparation was examined with the use of differential thermal and thermogravimetric analyses, X-ray diffraction analysis, X-ray photoelectron spectroscopy, and elemental spectral analysis. The catalytic system prepared by the impregnation of electrochemically treated Busofit with the solutions of PdCl, FeCl, CuBr, and Cu(NO ) and activated under optimum conditions ensured 100% CO conversion under a respiratory regime at both low (0.03%) and high (0.5%) carbon monoxide contents of air. It was found that the activation of a catalytic system at elevated temperatures (170-180°C) leads to the conversion of Pd(II) into Pd(I), which was predominantly localized in a near-surface layer. The promoting action of copper nitrate consists in the formation of a crystalline phase of the rhombic atacamite CuCl(OH). The catalyst surface is finally formed under the conditions of a catalytic reaction, when a joint Pd(I)-Cu(I) active site is formed. © 2014 Pleiades Publishing, Ltd.

Project financing 8th edition

The eighth edition is a fundamental and essential update to the seventh edition published in 2000. This new edition examines a comprehensive range of existing and newer topics that are relevant to project financing in 2012 and explores current trends in the project finance and leasing industries. Contributors are experienced academics and practitioners. Since the first edition was published, the financial markets have undergone tremendous upheavals and many new structures and instruments have been created to meet the financing needs of business. This edition considers the wider world of project finance, applicable to such diverse situations as venture capital and leveraged buyouts, and using new approaches such as Islamic finance techniques. The eighth edition is an essential and over-due update to the previous edition published in 2000. The eighth edition updates a comprehensive review of financial and related topics which are relevant to project financing in 2012 and explores current trends in financial modelling of a project, risk management and the private finance initiatives. This is a comprehensive and practical book full of advice and tips for successful project financing, including leasing, offering a clear, easy to understand guide to a complex area with examples. The topic coverage is well organized and complete moving from the fundamentals to the more complex issues. There is an extensive glossary to support readers. Finally the use of 12 practitioner case studies brings many of these complex issues to life. This is the new edition of the clear, easy-to-understand industry-standard text on project financing. With a good overview of a broad area and using principles of project financing to explain complex structures, this book includes lots of examples and case studies (including Eurotunnel, Dabhol, multiple Paiton deals and other recent deals along with subsequent developments) to show the concepts in use, examine outcomes and to ensure you understand important issues such as effective project structuring and financing, financial modelling for project valuation, and risk management. Substantially updated and expanded to provide the latest developments in all aspects of project financing. An important manual reference, this book is a must-have for every project financier's desk. The text unites the domain of project financing with a wealth of project management techniques, supported by diagrams and charts and other pictorial features, where appropriate. All these supporting features facilitate a better understanding of the accompanying text for the reader. In many chapters there are diagrams to clarify the specific transaction structure discussed in the accompanying text. These diagrams enable the reader to get a very clear idea of the transaction structure, which is particularly useful where it is complex or unusual. There are also a number of checklists to assist stakeholders in the project and resource management of complex project financings. The new financial modelling chapters allow exploration of some of the pitfalls project models encounter, challenging the accurate replication of the project cash flows for stakeholders to evaluate. In the later new risk management chapters, worked examples are included to illustrate the techniques in practice. The new public private partnership/private finance initiatives chapter introduces readers to this new approach to public projects. References are made to useful websites throughout the text. Cases are included at the end of the main text to encourage examination of real-life examples of project financing in practice and also highlight specific issues of current interest. The book will be helpful to project finance sponsors, lawyers, host governments, bankers and providers of capital

Quantitative authorship attribution:an evaluation of techniques

The basic assumption of quantitative authorship attribution is that the author of a text can be selected from a set of possible authors by comparing the values of textual measurements in that text to their corresponding values in each possible author's writing sample. Over the past three centuries, many types of textual measurements have been proposed, but never before have the majority of these measurements been tested on the same dataset. A large-scale comparison of textual measurements is crucial if current techniques are to be used effectively and if new and more powerful techniques are to be developed. This article presents the results of a comparison of thirty-nine different types of textual measurements commonly used in attribution studies, in order to determine which are the best indicators of authorship. Based on the results of these tests, a more accurate approach to quantitative authorship attribution is proposed, which involves the analysis of many different textual measurements.

Applied pharmaceutical practice

Applied Pharmaceutical Practice is an invaluable resource and will guide the student pharmacist and pharmacy technician through the main stages involved in pharmaceutical dispensing. As a core reference text, it is ideal as a companion to the compulsory dispensing courses found in all undergraduate MPharm programmes and the equivalent technical training courses. Contents include: •medicines classification and standard operating procedures •NHS supply in the community and within hospitals •non-NHS supply •controlled drugs •emergency supply •patient counselling and communication •poisons and spirits This practical textbook contains useful exercises with an answers section and numerous examples and is written by authors with extensive experience within the field. This is a comprehensive guide through the main stages of pharmaceutical dispensing.The textbook is designed to guide student pharmacists or pharmacy technicians through the main stages involved in pharmaceutical dispensing. It provides students with a core reference text to accompany the compulsory dispensing course found in all pharmacy undergraduate programmes, highlighting and explaining all key concepts behind the processes involved in pharmaceutical dispensing.

Phase noise influence in coherent optical DnPSK systems with DSP based dispersion compensation

We present a comparative study of the influence of dispersion induced phase noise for n-level PSK systems. From the analysis, we conclude that the phase noise influence for classical homodyne/heterodyne PSK systems is entirely determined by the modulation complexity (expressed in terms of constellation diagram) and the analogue demodulation format. On the other hand, the use of digital signal processing (DSP) in homodyne/intradyne systems renders a fiber length dependence originating from the generation of equalization enhanced phase noise. For future high capacity systems, high constellations must be used in order to lower the symbol rate to practically manageable speeds, and this fact puts severe requirements to the signal and local oscillator (LO) linewidths. Our results for the bit-error-rate (BER) floor caused by the phase noise influence in the case of QPSK, 16PSK and 64PSK systems outline tolerance limitations for the LO performance: 5 MHz linewidth (at 3-dB level) for 100 Gbit/s QPSK; 1 MHz for 400 Gbit/s QPSK; 0.1 MHz for 400 Gbit/s 16PSK and 1 Tbit/s 64PSK systems. This defines design constrains for the phase noise impact in distributed-feed-back (DFB) or distributed-Bragg-reflector (DBR) semiconductor lasers, that would allow moving the system capacity from 100 Gbit/s system capacity to 400 Gbit/s in 3 years (1 Tbit/s in 5 years). It is imperative at the same time to increase the analogue to digital conversion (ADC) speed such that the single quadrature symbol rate goes from today's 25 GS/s to 100 GS/s (using two samples per symbol). © 2014 by Walter de Gruyter Berlin/Boston.

Implementation of pseudo J-integral based Paris’ law for fatigue cracking in asphalt mixtures and pavements

Pavement analysis and design for fatigue cracking involves a number of practical problems like material assessment/screening and performance prediction. A mechanics-aided method can answer these questions with satisfactory accuracy in a convenient way when it is appropriately implemented. This paper presents two techniques to implement the pseudo J-integral based Paris’ law to evaluate and predict fatigue cracking in asphalt mixtures and pavements. The first technique, quasi-elastic simulation, provides a rational and appropriate reference modulus for the pseudo analysis (i.e., viscoelastic to elastic conversion) by making use of the widely used material property: dynamic modulus. The physical significance of the quasi-elastic simulation is clarified. Introduction of this technique facilitates the implementation of the fracture mechanics models as well as continuum damage mechanics models to characterize fatigue cracking in asphalt pavements. The second technique about modeling fracture coefficients of the pseudo J-integral based Paris’ law simplifies the prediction of fatigue cracking without performing fatigue tests. The developed prediction models for the fracture coefficients rely on readily available mixture design properties that directly affect the fatigue performance, including the relaxation modulus, air void content, asphalt binder content, and aggregate gradation. Sufficient data are collected to develop such prediction models and the R2 values are around 0.9. The presented case studies serve as examples to illustrate how the pseudo J-integral based Paris’ law predicts fatigue resistance of asphalt mixtures and assesses fatigue performance of asphalt pavements. Future applications include the estimation of fatigue life of asphalt mixtures/pavements through a distinct criterion that defines fatigue failure by its physical significance.

The effects of bilingual and monolingual reading videos on story recall with students who are deaf and hard of hearing

The purpose of this study is to investigate the effects of bilingual and monolingual videos on the reading comprehension of students with significant hearing impairments and/or deafness. Children with and without hearing losses need reading programs in which comprehension of meaning is the primary goal. This can occur only when print is represented in meaningful context, allowing children to create meaning from their own experience, background, and knowledge of language.^ Investigated in this study was whether students with significant hearing losses comprehended more information in a bilingual or monolingual instructional video format. There were three instructional videos produced: (a) the bilingual video which incorporated American Sign Language (ASL) with standard English captions, (b) a monolingual English video with standard English captions only, and (c) a monolingual ASL-only video. It was hypothesized that the effects of English captioning with ASL might serve as a bridge during instruction, increasing reading comprehension and written English for students. It was further hypothesized that this would allow students to integrate their own ASL knowledge to the printed text to construct meaning.^ Four separate analyses were conducted to see if the hypothesis was supported by the findings. However, all results indicated that there were no significant differences in students' written measures of reading comprehension recall across any of the three presentations of information (two monolingual and one bilingual condition). There were seven variables (word identification, word recall, sentence recall, story recall, written passage theme, written passage word count, and number of mature words) used to evaluate reading comprehension recall. No variable, either individually or grouped, demonstrated a significant difference between monolingual or bilingual instruction. ^

Design of an automated book reader as an assistive technology tool for blind persons

This dissertation introduces a novel automated book reader as an assistive technology tool for persons with blindness. The literature shows extensive work in the area of optical character recognition, but the current methodologies available for the automated reading of books or bound volumes remain inadequate and are severely constrained during document scanning or image acquisition processes. The goal of the book reader design is to automate and simplify the task of reading a book while providing a user-friendly environment with a realistic but affordable system design. This design responds to the main concerns of (a) providing a method of image acquisition that maintains the integrity of the source (b) overcoming optical character recognition errors created by inherent imaging issues such as curvature effects and barrel distortion, and (c) determining a suitable method for accurate recognition of characters that yields an interface with the ability to read from any open book with a high reading accuracy nearing 98%. This research endeavor focuses in its initial aim on the development of an assistive technology tool to help persons with blindness in the reading of books and other bound volumes. But its secondary and broader aim is to also find in this design the perfect platform for the digitization process of bound documentation in line with the mission of the Open Content Alliance (OCA), a nonprofit Alliance at making reading materials available in digital form. The theoretical perspective of this research relates to the mathematical developments that are made in order to resolve both the inherent distortions due to the properties of the camera lens and the anticipated distortions of the changing page curvature as one leafs through the book. This is evidenced by the significant increase of the recognition rate of characters and a high accuracy read-out through text to speech processing. This reasonably priced interface with its high performance results and its compatibility to any computer or laptop through universal serial bus connectors extends greatly the prospects for universal accessibility to documentation.

Dulce Maria Loynaz' Jardin: Subversive tropological discourse

The purpose of this dissertation is to analyze how the tropes or figurative discourse in Loynaz’s novel, Jardín, becomes a means by which she involves the reader within a text that subverts socio-cultural conventions. Through textual analysis, it explains how the poet communicates her views of the world as a conflictive space where existence is the will to live, life being a human construction like a garden, and a woman’s decision –often frustrated by men– to seek self-realization.^ By tracing some critical studies focused on polarities allegedly present in Jardín, such as: poetry/prose, lyric poetry/novel, word/silence, life/death, character novel/space novel, civilization/barbarism, posmodernismo/vanguardismo, and femininity/feminism, this essay explores Loynaz’s esthetic and ideological codes to demonstrate how opposition can be seen in her novel as part of her arrangement of an artistic philosophy.^ This research refers to three main sources: the semiotician Umberto Eco’s notion of the text’s indeterminacy as an opera aperta, reception theory, and Mikhail Bakhtin’s concept of dialogism. By applying these theories to the analysis of this novel, I seek to show Loynaz’s literary modus (tropological language) and ideological dictum , which correlate oppositions and transform them as a point of departure to reconsider civilized life. The poet is presented as an esthetic force that compels the reader to question some false values, by creating an implicit but intelligent dialogue between him/her and a lyrical text. To describe such literary procedure, I coin in this study the term dialirismo (dialyricism). ^ My essay is centered on the tropes through which Loynaz creates her dialyrical text. By focusing on metaphor, symbol, synecdoche, and metonymy, I examine Jardín as a convergence of the following conceptual aspects: intertextuality, primitivism, and feminist discourse. I argue that Loynaz’s novel is a creative response to the literary tradition, as well as a proposal to understand writing –and reading– as an open, interactive process in search not only of artistic values but also of critical knowledge.^ This exploration shows how the novelist faces a so-called civilized world through the eyes of her fictional character, Bárbara, who confronts patriarchal discourse. It celebrates Loynaz’s poetic representation of this inquisitive woman, in her fenced garden, as a human being who can see, above and beyond an iron curtain, the possibility to overcome an aggressive male-centered civilization.^

A Musicology for Literary Language

This study analyzed the reader's relationship to the sounds embedded in a written text for the purpose of identifying those sounds' contribution to the reader's interpretation of that text. To achieve this objective, this study negotiated Heideggerian phenomenology, Freudian and Lacanian psychoanalysis, linguistics, and musicology into a reader response theory, which was then applied to Edgar Allen Poe's "The Raven." This study argues that the orchestration of sounds in "The Raven" forces its reader into a regression, which the reader then represses, only to carry the resulting sound-image // away from the poem as a psychic scar.