PhD

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Open Access
'Solubilisation of Arsenic, Gallium Arsenide arid Tin by Alkyl Halides'
(De Montfort University, 1993-04) McDonagh, Reman
A naturally occurring compound methyl iodide is formed through the biological intermediacy of some fungi and marine algae. The alkyl iodide mobilises metals out of water - insoluble compounds and/ or anoxic sediments by formation of bonds between the methyl group and heavy metals or metalloids. Dissolution of tin and arsenic by treatment with aqueous methyl iodide follows a standard kinetic pattern, which can be derived from a simple model that is based on formation of alkyltin and alkylarsenic iodides. The rate and extent of dissolution depends on the substrate, the nature and concentration of methyl iodide and the surface of the substrate. Various techniques were employed to investigate the reaction. The extent of solubilisation wa analysed using ICP to establish reaction rates and pathway . Speciation of tin and arsenic was monitored using GC coupled to an AAS. As well as the environmental importance of metal recovery, the treatment was extended to examine the surface changes produced. Using a SEM coupled to an EDAX the surface morphological defects revealed after treatment of gallium arsenide wafers were observed. The potential application of the treatment of GaAs with aqueou methyl iodide were discussed.
Open Access
INSTRUMENTATION AND CONTROL OF AN INDUSTRIAL SEWING MACHINE
(De Montfort University, 1997-10) MATTIE-SULEIMAN, EMAN A
To compete with garment manufacturers world-wide , it is essential that the British sewing industry automates. In order to achieve this automation sewing machines must be capable of measuring and controlling their performance. The advancement of practical, automated, high speed sewing machines, which are capable of optimising sewn seam quality, will greatly benefit the garment industry. Research on sewing ability has led to a greater understanding of the complex interactions involved in joining two or more plies of material with thread. Analysis of the joining system has become important with the increase in the sewing speed. The problems related to sewing ability increase with the higher sewing speeds used to join the newer textile materials. Changes to finer gauge knits and fabrics finished with different dyes and finishes, together with widespread acceptance of synthetic fibres in both fabrics and sewing threads, create new sewing problems. A number of researchers have made recommendations on how to minimise the problems, however, as the apparel industry becomes more automated new requirements become desirable, for example sewing machines with no direct control exerted by the operator on the sewing machine or the fabric. In addition sewing machines in the manufacturing environment will be required to be more flexible to perform equally efficiently across a wider range of fabrics. The dynamics of the fabric feeding system, and the needle and looper thread interactions are the prime variables investigated. This research concentrates on the modelling and control of the three thread overlock sewing machine such that optimal quality seam, which makes up the garments, is achieved. The sewing machine is envisaged as two systems, the fabric feeding systemand the sewing thread dynamic system. To control the sewing thread dynamic system, an intelligent knowledge based supervisory control system is developed. During sewing operation, some problems such as fluff accumulation and twists in the thread alter the thread system dynamics. To overcome such variations, the sewing thread system is decomposed into three sub-systems, each having its own low level controller to control the thread displacement per stitch. . Two types of low level basic direct control namely the Adaptive Model Following Control (AMFC) and Fuzzy Logic Control (FLC) are implemented on each of the sub-systems and comparisons between the two type of methodologies are made. These comparisons are based on the performance, robustness, and ease of implementation. It shows the similarities and differences in performance with respect to the designed controller. Different approaches can be adopted towards the automation of the sewing machine and these are discussed. The chosen design is based on a supervisory control system constructed as a multi-layered hierarchical structure where the lowest level is the basic direct control and the higher level is the supervisory control which influences the process indirectly. This enables the designer to increase the level of automation in steps by including or considering more number of variables. This approach has also been chosen because its adaptation mechanism imitates the expert sewing operator in controlling the sewing performance.
Open Access
THE THERMODYNAMIC PROPERTIES OF SOME BINARY MIXTURES CONTAINING CYCLOHEXANOL, CYCLOHEXANONE AND CYCLOHEXYLAMINE
(De Montfort University, 1978-01) Martin, Robert
Open Access
Studies on the Pharmacokinetics of Pinacidil in Healthy Volunteers
(De Montfort University, 1988-11) McBurney, Alan
Analytical methods were developed for the determination of pinacidil and its major metabolite, pinacidil pyridine N-oxide, in serum and urine. Using these methods, the pharmacokinetics of pinacidil were studied following intravenous and oral administration of the drug to healthy volunteers. Additional pharmacokinetic studies included the effect of food on the absorption of pinacidil and the effects of chronic dosing with pinacidil in middle-aged, healthy volunteers. The final study was an investigation of a possible correlation between the 4-hydroxylation of debrisoquine, the N-oxidation of trimethylamine and the N-oxidation of pinacidil in Caucasian volunteers. Pharmacokinetic analysis was performed by means of computer programs written or amended by myself for use with a Commodore PET microcomputer and by using the nonlinear regression program BMDP. The major pharmacokinetic parameters of pinacidil in healthy volunteers were; Clearance = 32.3 ± 10.3L/h; Apparent Volume of Distribution = 102.9 ± 16.6 L. The serum elimination half-life of pinacidil was 2.4 ± 0.7h. Pinacidil was found to be cleared from the body primarily by hepatic clearance and to have a low to medium hepatic extraction ratio. Renal clearance was low and there was evidence that pinacidil is subject to tubular reabsorption. Little pinacidil was excreted unchanged in urine, less than 5% of the administered dose in 24h. The main metabolite was pinacidil pyridine N-oxide, which accounted for up to 80% of the dose excreted in urine in some subjects. Urinary excretion of metabolite was increased following oral administration of pinacidil and chronic dosing led to accumulation of the metabolite in serum. Concomitant administration of sustained-release pinacidil with food was found to increase pinacidil bioavailability and reduce intersubject variation in the maximum serum concentration of pinacidil. There was no correlation observed between the 4-hydroxylation of debrisoquine and the N-oxidation of pinacidil or between the N-oxidation of trimethylamine and the N-oxidation of pinacidil.
Open Access
WAVELET BASED IMAGE COMPRESSION OF INTEGRAL THREE DIMENSIONAL VIDEO SIGNALS
(De Montfort University, 2006-03) MAZRI, MERIEM
With the development of 3D Integral Imaging, image compression becomes mandatory for the storage and transmission of 3D Integral Images. In this thesis, the implementation of the Discrete Wavelet Transform for the compression of still 3D Integral Images is discussed. As a necessary background, the basic concepts of Integral Imaging and existing compression algorithms are discussed. The mathematical properties of wavelets are covered and the multi-resolution characteristic of the Discrete Wavelet Transform is highlighted. The Mallat algorithm and Filter bank theory are introduced and their application on images is presented. The nature of the three-dimensional images investigated is such that there is strong correlation between sub-image elements. It is proposed that to exploit this correlation effect, the compression technique is based around the Discrete Wavelet Transform. Two different new algorithms are presented based simultaneously on the two-dimensional and three-dimensional DWT. In both techniques, the method requires the extraction of different viewpoint images from the Integral Image. The first algorithm proposed is based on a two-levels two-dimensional DWT applied on the different viewpoint images using the Daubechies 9/7-tap biorthogonal filter bank. In the second algorithm, the spatial wavelet decomposition on a single viewpoint is performed in a similar way, while the inter-viewpoint image decomposition on the sequence is performed using the lifting scheme by means of the 5/3 biorthogonal transform. The extension to images containing full parallax information in both horizontal and vertical directions is demonstrated. In order to apply compression techniques to the type of images investigated, the pixel structure of the sub-images has to be manipulated. Improved performance in both rate distortion and image quality is achieved over previously reported 3D DCT based compression algorithms especially at very low bit rates.
Open Access
THE DESIGN OF A NOVEL ANTI-TUMOUR DRUG DELIVERY SYSTEM USING IMMUNE-DERIVED CELLS.
(De Montfort University, 1992-05) LILLEY, JACQUELINE CAROL
Exploitation of the natural ability of some immune-derived cells to target and kill tumour cells has been approached by use of the cells in conjunction with liposomes which have been used to carry a wide variety of therapeutic agents. The proposed delivery device combines the two approaches of targeting liposomes specifically to tumours and metastases and the adoptive immunotherapy of monocytes and/or macrophages. It involves encapsulation of chemotherapeutic drug within a liposomal matrix which affords protection from the host-immune response by uptake of the drug-liposome, combination into macrophages. Liposomes were prepared containing either the fluorescent probe carboxyfluorescein located in the liposomal aqueous phase, or the anticancer drugs doxorubicin or mitoxantrone which located in the lipid bilayer. Unelicited murine peritoneal macrophages were chosen as the m􀀂crophage model for the present study and attempts were made to isolate them from murine peritoneal exudate. The isolation of monocytes from human whole blood was also conducted since it would be necessary to carry out further studies in a human model. The number of unelicited murine peritoneal macrophages available for injection was maximised by culture of the macrophages in polyallomer centrifuge tubes- a substratum to which minimum adherence and a similar level of phagocytosis occurred compared to plastic or Teflon film. The effect of lipid type, charge, pre-incubation of liposomes in serum and liposomal concentration upon uptake of carboxyfluorescein liposomes by murine peritoneal macrophages in vitro was found to be negligible with respect to the concentration of carboxyfluorescein ingested. However, uptake in vivo of i.p. injected mitoxantrone and doxorubicin liposomes was considerably higher than that observed in vitro and the many liposomes ingested occupied a large volume of intracellular space within the macrophages. Furthermore, the macrophages were observed to retain their viability after liposome internalisation. Observation of cells using a laser light confocal microscope revealed that mitoxantrone was retained in the internalised liposomes compared to the doxorubicin of which much was released and collected at the nuclear membrane as was also observed with the free doxorubicin. The mitoxantrone liposomes were considerably less toxic to a human breast cancer cell line (MCF-7) in vitro than free mitoxantrone but more toxic than the drugfree liposomes which had a negligible cytotoxic effect. The murine peritoneal macrophages (MPM) containing mitoxantrone liposomes were more toxic in a 10:1 than a 1:1 MPM:MCF-7 ratio. This suggested that the toxicity was dependent upon the concentration of available free mitoxantrone which is consistent with observations by others for the intact release of doxorubicin from macrophages. Liposomes were labelled with [3H]-mitoxantrone and their distribution was observed in mice alone and within murine peritoneal macrophages loaded in vivo. The label was located predominantly in the liver, spleen, gut and carcass one hour after i.v. injection into a litter mate which revealed that the macrophages containing the liposomes were not trapped in the lungs and were therefore capable of reaching a tumour target.
Open Access
Development of less toxic analogues of fascaplysin as novel therapeutic agents for the treatment of cancer
(De Montfort University, 2007-03) Mahale, Sachin Govindrao
Cyclin-dependent kinase 4 (Cdk4) represents a crucially important target for the treatment of cancer because most human cancers are characterised by over-expression of its activating partner cyclin Dl (product of an oncogene), loss of the natural Cdk4 specific inhibitor p 16 INK4A or mutation in Cdk4' s catalytic subunit. Even the target of Cdk4, pRb, is found to be functionally inactive in many human tumours. All of these aberrations can cause deregulated cell growth, resulting in tumour formation. Therefore, a small synthetic molecule or a natural product that specifically and potently inhibits the kinase activity of Cdk4 in vitro and prevents cell growth and tumour volume in vivo could be of immense therapeutic value for the treatment of cancer. Fascaplysin is a marine natural product which is a potent Cdk4-specific inhibitor. However, fascaplysin also intercalates DNA resulting in S phase block in the cell division cycle and unusual toxicity at the cellular level. The purpose of these studies was to develop a less toxic analogue of fascaplysin that abolishes fascaplysin's DNA binding capacity but maintains its potency to inhibit Cdk4 so as to obtain a novel therapeutic agent for the treatment of cancer. The newly synthesized compounds (based on the structure of fascaplysin) were screened in five different Cdk enzyme assays: Cdk4-cyclin Dl, Cdk2-cyclin A, Cdk2-cyclin E, Cdkl-cyclin B1 and Cdk9-cyclin Tl. The results from these assays led to the identification of compounds that specifically inhibit Cdk4 enzyme activity in vitro (i.e. compounds that are, at least, 10-fold more potent in inhibiting Cdk4 than Cdk2, Cdkl or Cdk9). Interestingly, none of fascaplysin's analogues showed any interaction or intercalation with double-stranded DNA, proving that fascaplysin's ability to inhibit Cdk4 specifically can be separated from its deleterious DNA intercalating characteristic. These structural analogues of fascaplysin were tested for their ability to inhibit cancer cell growth in vitro. We have succeeded in identifying novel molecules (from the screening of four different series of compounds) which inhibit the growth of cancer cells in vitro at low micro-molar concentrations. The most active compounds CAI 99, CA224, AJW089 and DE002 inhibited growth of cancer cells at an average IC50 concentration of 7, 4.2, 2 and 0.74 µM respectively. The effects on the long term survival (colony forming ability) of cancer cells in vitro followed by the treatment with the compounds were also evaluated. Colony forming ability usually reflects an anticancer compound's efficacy in viva. It was found that these compounds significantly reduce the colony forming ability of cancer cells in vitro. Compounds showing potent anti-proliferative effects were studied further for their effects on the cell division cycle. To our surprise, some of the analogues manifested not only the expected Cdk4-specific inhibition by blocking at the G0/G1 phase of the cell cycle but also exhibited a G2/M phase block in a Cdk-independent manner. The unexpected G2/M block posed many questions regarding the possible dual mechanism of action of these compounds. Interestingly, we found that the fascaplysin analogues that show profound block at G2/M phase also inhibit tubulin polymerization both in an in vitro cell-free assay as well as in a cell-based assay. Further experiments were performed to evaluate the effect of these compounds on the expression levels of the tumour suppressor proteins pRb and p53 by Western blotting. It was found that CA199 and CA224 enhanced the expression levels of p53 but did not alter the expression levels of the pRb protein. CA 199 and CA224 were also found to induce the levels of cell cycle inhibitory proteins p27KJPJ and p21CIPJ/WAFJ _ Western analyses to check the phosphorylation status ofpRb protein at Cdk4 specific sites (Ser780, Ser795 and Ser8071811) indicated that the block of cancer cell growth at G0/G1 was mediated by Cdk4. Although most of the synthesised molecules are Cdk4-specific, yet they do not manifest their cellular activities only via Cdk4. Intriguingly, we confirm that some selected compounds manifest their cellular action by targeting multiple sites in the cancer cell division cycle. We also show that two of these selected compounds are highly efficacious in inhibiting tumour growth in human xenograft-SCID mice models. In animal studies, CA224 and DE002 significantly inhibited the in viva tumour growth ofHCTl 16 (human colon cancer) and NCI-H460 (human lung cancer).
Open Access
Repetitive Movement Problems in the Horse and the Development of Welfare Orientated Treatment Strategies
(De Montfort University, 2003-06) Mills, Daniel S.
Open Access
Some Aspects of the Chemistry of Benzodiazoles
(De Montfort University, 1970-04) Jaffari, GhayoorAbbas
Open Access
A Contribution to the Chemistry of 1,2,3-BENZOTHIADIAZOLE
(De Montfort University, 1964-06) Heard, David Dunn
The chemistry of systems containing the 1,2,5-thia;diazole The nitration of 1,2,5-henzothiadiazole and the chlorination, iodination, diazo-coupling, and nitration of the four amino-l,2,3--henzothiadia2oles and some of their N~acyl derivatives have been studied. Differences in the 300-350 region of the spectra of 2- and 4-phenylazo-l-naphthylamines are found in analogous derivatives of 1,2,3-benzotEiadiazole and are used to orientate products of diazo-coupling. The reasons for believing that 1,2,3-benzothiadiazole is a cyclic ring compound are reviewed. Its pKa and ultraviolet spectrum are discussed. Evidence that the -NsN- group in 1,2,3-benzothiadiazole resembles a nitro-group is quoted and this fact together with the suggestion that there is partial bond fixation in the benzene ring is used to explain the products of electrophilic substitution. Much of the work described in this thesis has already been published 1,2 and the remainder is largely incorporated in a third paper. The latter has recently been recommended for publication in the Journal of The Chemical Society.
Open Access
The use of 1,2,3,4-tetrasubstituted benzenes in the synthesis of novel heterocyclic systems (fused [a,c] benzenes)
(De Montfort University, 1980-12) Groves, Clive Leslie
Open Access
Photography: Locus Suspectus
(De Montfort University, 2001-04) Collingham, Maria
The fundamental aim of this research has been to produce an original body of work, which engages with theoretical and key texts enabling me to place my practical photographic work within a contemporary critical framework. Whilst work has been informed by theoretical concerns, the work is by no means an illustration of theory. My engagement with key texts has acted as a springboard for an imaginative practice that allows for an experimental approach. My exploitation of the photographic medium has extended the possibilities of an engagement with certain subject areas and themes, most notably the subject of the female figure within representation. The body of research presents a representation of the female figure which disrupts and questions notions of the female as object rather than subject. The work aims to present and reflect elements of female experience. In this research project I have investigated the formal construction of the photographic image with particular reference to colour and composition in order to construct meaning, whilst paying particular attention to viewer relationships. My analysis of formal construction has been informed by the work of other artists both past and present. Practical photographic work will be presented at the City Gallery, Leicester 2nd - 7th April 2001.
Open Access
A Systems Approach to Reengineering Business Processes Towards Concurrent Engineering Principles
(De Montfort University, 1999-01) Clegg, B. T.
This thesis presents a description of a soft system methodology for business process improvement. The research is based on earlier work by Cole [ 1997|. It extends and adds rigour to that w'ork and presents original knowledge which is shown to be particularly useful in creating hierarchies of process knowledge. A new form of process model is presented. These exhibit richer systemic attributes than previous work could provide. The ideas described have been extensively tested in industrial contexts. The case studies presented were an attempt to systematically and holistically examine business processes in systems engineering companies to adopt and practice concurrent engineering principles. In order to maintain a sound methodological approach the author began this research with a thorough review of the literature on concurrent engineering, systems thinking, and the management of process change (which includes 'total quality management' and 'business process reengineering'). Together, the knowledge obtained from the systems thinking and change management literature is considered instrumental in managing the change of processes; where the objective is taken to be the full adoption of concurrent engineering pri nciples. I he literature review identifies a spectrum of systems types and a spectrum of systems investigation techniques focused around process modelling. How'ever, no single systems type or investigation technique is considered entirely appropriate for supporting the management of processes improvement towards concurrent engineering principles. Therefore, the author has derived and defined a new systems type (known as 'qnasi- hard'} and some new investigative techniques to match; which are called the 'Process OrientatedHolonic' (PrOH) modelling techniques. These are derived from both 'hard' and 'soft' systems thinking so that business processes can be depicted in an unambiguous, hierarchical manner, and express issues pertinent to human activity systems. It has been necessary to develop these new techniques in an 'action research' style. This has meant that industry has actively participated in their evolution. In return, the collaborating companies have benefited by having their processes modelled and critiqued, these arc described in two case studies. The academic community has also benefited from this research through numerous publications and presentations. The author believes that this programme of research has been very successful in meeting its objectives.
Open Access
Craft-Focused Electronic Musical Instrument Building: Exploring DIY Textiles and Hybrid Craft Techniques in Sound Arts Practice
(De Montfort University, 2024-09) Topley, Samantha Jane
The aim of this practice-led research was to explore the concept of a craft focused electronic musical instrument building practice, prioritising textile handcraft materials, techniques and aesthetics in the process of creating new electronic musical instruments and sound artwork. A range of DIY textile crafts and hybrid craft techniques (such as knitting, embroidery and pompom making, often with electronic textile materials) were used to create novel and alternatively designed ideas, working with other colours, textures, forms, methods of construction and means of performance. Craft led the design, utilising the properties of the materials and craft processes to explore unconventional design concepts, such as round, soft and colourful objects. A portfolio of fourteen projects, including electronic musical instruments, interfaces, installations and sound art objects were made. Crafted forms were made to house the technology, as well as using many different techniques to construct the tactile instruments and interfaces in their entirety. The practice of building electronic musical instruments was reframed with a craft-focused lens, with ideas not usually considered whilst instrument building, broadening the potential toolkit for others in the practice. Each project was unique with regards to material, method of construction or method of performance, offering many novel artistic and technical design concepts. The projects were created with craftivist intent, suggesting craft’s potential to democratise and address current cultural, socio-political, socio-economic and environmental issues in creative music technology practices. The work was presented and shared with different audiences, mostly happening in community and grassroots settings, exposing new audiences to themes related to the sonic arts through craft-focused ideas. The documentation of this practice-led research offers an original contribution to knowledge, adding to the discourse on electronic musical instrument building and hybrid crafting in sonic arts practice.
Open Access
“Is wa really a go on inna da place ya?” An Investigation into Sustainable Aviation in the Caribbean
(De Montfort University, 2024-08) Mc Call Jr, Dennis
The Caribbean, consisting of Small Island Developing States and spanning over 7,000 islands and continental territories, is a diverse and culturally rich region. Thanks to its tropical allure, it ranks among the world's premier tourist destinations, with both international visitors and locals heavily reliant on air travel as their primary mode of transportation. In contrast to other transportation sectors that have made substantial strides in mitigating their environmental footprint, aviation lags behind. To address the environmental challenges posed by the aviation industry, experts have championed the concept of sustainable aviation. This approach seeks to strike a balance between promoting economic growth, fostering social progress, and safeguarding the environment. Despite a growing body of literature on sustainable aviation, its impact on the Caribbean has been largely overlooked. This research aims to investigate the development of sustainable aviation in the Caribbean and develop recommendations for sustainable aviation that would foster the development of both the aviation sector and the region as a whole. Recognizing the pivotal role of various aviation stakeholders in shaping the industry's trajectory, this study is grounded in stakeholder theory. Key stakeholders within the aviation domain were identified, encompassing air navigation service providers, airline suppliers, airlines, airports, aviation regulators, the business community, educational and training institutions, financial services, governmental bodies, non-governmental organizations, passengers, tourism partners, and unions. The findings underscore the significance of aviation in propelling economic growth and social advancement in the Caribbean. However, the industry faces multifaceted challenges that have led to a decline in intra-regional travel. Additionally, while the concept of sustainable aviation is acknowledged, a lack of policies and practices impede its development. It is noteworthy that the regional aviation stakeholders maintain a positive rapport, suggesting that collaborative efforts hold promise for achieving sustainable aviation goals. The thesis’ recommendations entail the development of a sustainable aviation strategy for the Caribbean, the establishment of a regional aviation governing body, and a re-evaluation of the definition of sustainable aviation.
Open Access
Queer Reproduction: Horror, Landscape and Myth
(De Montfort University, 2025-02) Chantry, James
This practice research project considers the connections and intersections of the supernatural, queerness, and art making that speculates queer futures and communities. The project began with an exploration of ghost stories and their connection to repressed sexuality and identity, and mediumship and its relationship to gender transgression. These explorations revealed how art making can embody supernatural queer male birth, and I utilised feminist theory to suggest allegorical modes of alternative birth. Through my specific and personal connection to a geographic location - the Lincolnshire Fens in the UK - liminality, landscape, a wealth of folklore and a connection to queerness, politics, and the queer body’s relationship to the land are central to this project. I claim these spaces as queer and interpreted their political and historical contexts as such. This landscape provided me with opportunities for ethnographic practice through storytelling and site-specific performance, documentation of which forms part of this project. My collaborations with other performance artists garnered further insights into kinship and alternative forms of community. For example, when co-producing work for this project in Taiwan, I explored tangible queer spirituality and object relationships. Working in a transdisciplinary manner, I have produced charged and evocative time-based media artworks using methods of creation related to mediumship and the supernatural, and in particularly: performance, sculpture, drawing, and AI text and animation woven into installations. In this project, I propose queer futures that challenge hegemony, examine queer identity, and celebrate the downright weird.
Open Access
Quarternisation of Benzothiazoles and 1,2,3 - Benzothiadiazoles
(De Montfort University, 1964-11) Chadbourne, David John
The chemistry of 1,2,3-benzothiadiazola is briefly reviewed. The early work on the preparation and properties of methyl- and ethyl-1,2,3-benzothiadiazolium salts is described, and more recent work on 2-aryl-l,2,5-benzothiadiazolium salts is summarised. The limitations of methyl and ethyl iodides as quaternising agents for 1,2, 3-benzothiadiarzole are discussed. Alternative methods of quaternisation using the more reactive dimethyl and diethyl sul-phates, methyl toluene-p-sulphonate, and methyl and ethyl 2,4-dinitro- benzenesulphorates to give new quaternary salts are described and discussed. Ion-exchange methods were employed to obtain the halides of these quaternary salts. Alkyl-1,2,3-benzothiadiasolium salts were previously thought to be sulphonium salts. From the results of reductive fission of these salts, it now seems probable that the alkyl group is attached to N-3. Other evidence is also presented in support of this view. The results obtained for the preparation of methyl- and ethyl - 1,2,3-benzothiadiazolium salts indicated that esters of nitro-substituted benzenesulphonic acids (particularly 2,4-dinitrobenzene-sulphonates) would be most suitable for preparing higher alkyl- 1,2,3-benzothiadia7olium salts . The methods which have been used to prepare alkyl esters of aromatic sulphonic acids are reviewed. These techniques were then applied to the synthesis of alkyl, subsbitutod alkyl, and polymethylene bis 2,4-dinitrobenzGnesulphonates. The methods which were used to prepare the few alkyl 2,4-dinitrobenzonnaulphonatee previously recorded have been re-examined and the yields considerably improved. The quaternisation of 1,2,3-benzothiadiazole with higher alkyl, substituted alkyl, and polymethylene bis 2,4-dinitrobenzeoGsulphonat«s has been studied. A brief review of the quaternisation of benzothiaziole and some of its derivatives is given. Experiments on the quaternisation of benzothiazole using the esters of 2,4~dinitrobenzenesulphonic acid mentioned earlier were carried out to obtain a qualitative comparison of their reactivity*
Open Access
The Effects of total and partial inhibition of the sodium and pottassium-activated Adenosine Triphosphatase on the isolated perfused rabbit heart
(De Montfort University, 1985-05) Bakewell, Richard John
The effects of sodium pump blockade on myocardial potassium (K),so'dium (Na), calcium (Ca) , adenosine 5'- triphosphate (ATP),and creatine phosphate (CP) were studied in the isolated Langendorff-perfused rabbit heart.Changes in these parameters- were investigated in relation to the development of ventricular fibrillation (VF) and contractile failure.Sodium pump inhibition was effected either by reducing the perfusate K concen-^ration (Kq) to 1.1 mmol. 1“’' or zero, or by including luraol.l ’ ouabain in the control medium (K<, = 4.9 mmol. 1 ’). A reduced Kg or ouabain produced a progressive net cellular K loss,net cellular gains in Na and Ca,and qualitatively similar declines in ATP and CP.These studies indicated primary roles for Ca accumulation and high-energy phosphate depletion in the mechanisms underlying the production of VF and contractile failure.The onset of VF was not related to any critical K loss,Na gain,or decline in high-energy phosphates. Reducing the extracellular Ca concentration from.2.5 to 0.5 mmol. 1 I in the presence of Llmmol.r’ prevented VF,Ca overload,depletion of ATP and CP,and markedly attenuated the deterioration in contractile function.However, a large K loss and Na gain were not prevented.These findings further suggested roles for Ca accumulation and high-energy phosphate depletion in the electrical and mechanical dysfunction produced by sodium pump blockade and indicated that the deterioration in cardiac energy metabolism was Ca-mediated. The antifibrillatory action of 0.51 and 2.04 umol. I"’ verapamil in- hearts perfused with ouabain, and 2.04 umol. 1"’ verapamil in preparations exposed to 1.1 mmol. 1“'' correlated with the drug's ability to preserve ATP and CP. This protective action on cardiac energy metabolism was not mediated by an inhibition of Ca accumulation or by a marked reduction in ATP utilization.Experiments performed with 0.51 umol. 1“'' verapamil and 1.1 mmol. I”'' K„ indicated that the higher drug concentration may possess antiarrhythmic properties independent of its effects on cardiac energy metabolism.
Open Access
Evolving design & Control Strategies for Production Systems
(De Montfort University, 2000) Ardon-Finch, Jason
This thesis focuses on two issues: the design of operator walk cycles for Flexible Manpower Lines and the performance of the recently developed Control Point Policy [Gershwin, 1999] with a view to its application in multi part type flexible manpower lines and Flexible Machining Lines. A flexible manpower line forms an individual cell of a Linked-Cell Manufacturing System (L-CMS), developed within the Toyota Production System [Ohno, 1988]. The system, and consequently each cell, is designed to achieve Just-In-Time objectives. The production rate of a cell is dictated by (is, in fact, the inverse of) the Takt time. The Takt time is typically small, i.e.. comparable to the processing times of machines. Cells are operated with very little space allocated for the storage of in-process inventory and are required to exhibit the ability for quick and efficient changes in the rate of production. Extensive analysis, via the use of discrete event simulation, highlights the advantages of the CPP over Critical Ratio, a popular control policy for such systems. Particular attention is awarded to cases with small buffer sizes and Takt times; characteristics typical of flexible manpower lines. The results indicate that the CPP lends itself well to these situations and, as such, provides an ideal candidate for the control of multi part type flexible manpower lines and flexible machining lines. There are no readily available methods for the selection of parameter values for the CPP, i.e., the buffer sizes and hedging times, due to the policy’s recently being designed. An integrated GA-simulation search procedure has been established as part this research and is used for the identification of suitable values for these parameters. The technique and the results obtained provide further understanding of the benefits of the policy and insight into how and when the policy should be applied. Extensive analysis, via the use of discrete event simulation, highlights the advantages of the CPP over Critical Ratio, a popular control policy for such systems. Particular attention is awarded to cases with small buffer sizes and Takt times; characteristics typical of flexible manpower lines. The results indicate that the CPP lends itself well to these situations and, as such, provides an ideal candidate for the control of multi part type flexible manpower lines and flexible machining lines. There are no readily available methods for the selection of parameter values for the CPP, i.e., the buffer sizes and hedging times, due to the policy’s recently being designed. An integrated GA-simulation search procedure has been established as part this research and is used for the identification of suitable values for these parameters. The technique and the results obtained provide further understanding of the benefits of the policy and insight into how and when the policy should be applied. Extensive analysis, via the use of discrete event simulation, highlights the advantages of the CPP over Critical Ratio, a popular control policy for such systems. Particular attention is awarded to cases with small buffer sizes and Takt times; characteristics typical of flexible manpower lines. The results indicate that the CPP lends itself well to these situations and, as such, provides an ideal candidate for the control of multi part type flexible manpower lines and flexible machining lines. There are no readily available methods for the selection of parameter values for the CPP, i.e., the buffer sizes and hedging times, due to the policy’s recently being designed. An integrated GA-simulation search procedure has been established as part this research and is used for the identification of suitable values for these parameters. The technique and the results obtained provide further understanding of the benefits of the policy and insight into how and when the policy should be applied. Extensive analysis, via the use of discrete event simulation, highlights the advantages of the CPP over Critical Ratio, a popular control policy for such systems. Particular attention is awarded to cases with small buffer sizes and Takt times; characteristics typical of flexible manpower lines. The results indicate that the CPP lends itself well to these situations and, as such, provides an ideal candidate for the control of multi part type flexible manpower lines and flexible machining lines. There are no readily available methods for the selection of parameter values for the CPP, i.e., the buffer sizes and hedging times, due to the policy’s recently being designed. An integrated GA-simulation search procedure has been established as part this research and is used for the identification of suitable values for these parameters. The technique and the results obtained provide further understanding of the benefits of the policy and insight into how and when the policy should be applied. Variation in the throughput rate of a cell is achieved by altering the manning levels. Frequent changes in the number of operators within a cell require frequent redesign of operator walk cycles. Currently, walk cycles are constructed using a time-consuming, manual method. One aim of this thesis is to provide a flexible and efficient technique for the design of walk cycles, based on Genetic Algorithms (GAs), where either the Takt time or manning levels may be specified as the design constraint. A direct consequence of the efficiency of the technique developed is the ability to obtain greater knowledge of the relationships between system productivity, flexibility and manpower utilisation. The Control Point Policy (CPP) is a strategy for the real-time scheduling and control of production systems. The policy uses hedging points or hedging times to determine when machines should process parts. This thesis includes a continuation of recent investigations into the behaviour of the CPP but in a make-to-order., rather than make-to-stock, environment.
Open Access
Exploring the Business Case for Responsible Innovation
(De Montfort University, 2023-04) Bryce, Vincent
A series of national and international scandals - from Facebook-Cambridge Analytica, to Post Office Horizon and the collapse of the Dutch government over algorithmic profiling - are bringing the societal and commercial risks of irresponsible digital innovation into sharper focus. They highlight the responsibility challenges posed by smart information systems, and the potential impact of their misuse including misappropriation of personal data, loss of trust in institutions, and reputational and financial damage to businesses. At the same time, algorithmic technologies provide new opportunities for firms to develop competitive advantage through new capabilities. Emerging Human Resources technologies such as AI video interviewing indicate the potential these new technologies offer, and problematic aspects of how they gather and use personal data. These include tensions with legal or democratic norms, and the potential for previously-unknown technologies to move rapidly into mainstream use with unpredictable consequences. Responsible Research and Innovation (RRI) offers a new way to consider issues of responsibility in the development of information systems. The question of whether organisations that innovate responsibly experience benefits is uncertain, and mirrors long-standing debates in areas such as Corporate Social Responsibility (CSR) as to whether there is a business, as well as moral and legal case for responsibility, and if so, the conditions in which benefits can be achieved. This multidisciplinary work consists of two research directions: exploring the relationship between responsible innovation-related practices and benefits for organisations (including contextual considerations) and exploring the extent to which responsible innovation practices are applicable to technologies used in human resource management (HRM). The thesis examines the extent to which RRI can enable benefits to organisations, with specific reference to digital technologies and Human Resource Information Systems. It shows that responsible innovation practice is associated with a range of benefits; identifies a number of contextual considerations relevant to achieving these benefits; and demonstrates several ways in which responsible innovation practices are relevant to the development and implementation of emerging HRIS technologies. These include the empirical findings that a wider scope of RRI activity is associated with increased benefits to organisations; that culture and technology readiness level (TRL) can influence the realisation of RRI benefits; that the scope of data held about employees is rapidly increasing; that HRM literature has under-analysed algorithmic technologies; and that the RRI literature may not have fully considered the implications of technologies that enable cascading onward innovation. The thesis’ contribution to knowledge is to provide quantitative empirical insights relating to responsible innovation in industry, and to demonstrate the applicability of responsible innovation practices to organisations implementing emerging technologies. The thesis also establishes the relevance of responsible innovation methodologies to Human Resource Management practice, through interdisciplinary papers bridging the RRI, HRM, and computer ethics literature. Beyond academia, my findings are relevant to companies, HR and information systems professionals, and to public and non-governmental organisations seeking to promote responsible use of technology and personal data.

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