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Item Open Access Item Open Access Item Open Access Electrophilic Substitution and Diazo-Replacement Reactions of the Nitronaphthylamines and their N-Acyl Derivatives(De Montfort University, 1958-05) Wells, PeterN/AItem Open Access A Contribution to the Chemistry of 1,2,3-BENZOTHIADIAZOLE(De Montfort University, 1964-06) Heard, David DunnThe 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.Item Open Access Quarternisation of Benzothiazoles and 1,2,3 - Benzothiadiazoles(De Montfort University, 1964-11) Chadbourne, David JohnThe 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*Item Open Access Some Aspects of the Chemistry of Benzodiazoles(De Montfort University, 1970-04) Jaffari, GhayoorAbbasItem Open Access SOME STUDIES IN THE ALKYLATION AND TRANSPORT OF MERCURY IN THE ElVIRONMENT.(De Montfort University, 1977-03) MORTON, S. F. N.The history of mercury as an environmental pollutent is reviewed. The total mercury levels is a large polluted estuary, the River Mersey estuary have been determined. The estuary was found to be heavily polluted with mercury. On average, the sediments contained 2. 23 micro -grams of mercury in each gram of dry sediment. The maximum value found was 14. 3 ug 3-1 and the minimum was below the detection limit of 0.01 ug g -1 . To carry out this survey, published methods for the determination of mercury in sediments were considerably modified. The final method used was reasonably rapid, and gave results that compared well with duplicate samples anslysed in another laboratory. The mercury in the sediment samples was shown to be bound to organic material, and the distribution of mercury in the estuary reflected the distribution of organic material, rather than revealing any local sources of mercury discharge. Several sites were chosen for detailed investigation of methyl mercury levels. Published techniques for the determination of methyl mercury in sediments were found to be unsatisfactory, and were modified to improve the analytical precision. The final method used gave a relative standard deviation of 2% at the 20 ng g-1 level, and had a detection limit of approximately 1 ng-1 Initial methyl mercury levels measured in the sediments were found to vary widely, but were generally of the order of tens of nanograms per gram of dry sediment. The causes of this variation were investigated, and it was shown that the results obtained were consistent with a mechanism in which a methylating agent was biologically generated., and then reacted with the pollutant mercury in a simple chemical reaction to form methyl mercury. Published mechanisms for the reaction of methyl cobalamin and mercury are criticised, and a study of this reaction under very simple conditions was performed.. The results enabled a mechanism to be proposed, improved in certain essential aspects from previously published mechanisms. The affect of temperature on the reaction was studied, and the activation enthalpy and entroJy for the methylation reaction were calculated. On the basis of this mechanism and other published reactions, a route by which other organo-mercury species could feasibly be formed in the environment was proposed, which postulates the formation of halo-alkyl analogues of methyl cobalamin in the environment, followed by the transfer of the halo-alkyl group, to. mercury. Chloromethyl cobalamin was prepared, and the reaction with mercuric chloride was briefly investigated. The reaction was found not to be analogous with that of methyl cobalamin, and the only organo-mercury compound isolated from the reaction mixture was shown to be methyl mercury.Item Open Access The development of kinetic sculpture by the utilization of solar energy.(De Montfort University, 1978) Stonyer, Andrew AllanItem Open Access THE THERMODYNAMIC PROPERTIES OF SOME BINARY MIXTURES CONTAINING CYCLOHEXANOL, CYCLOHEXANONE AND CYCLOHEXYLAMINE(De Montfort University, 1978-01) Martin, RobertItem Open Access BIOCHEMISTRY OF THE N-METHYL-PYRROLIDINE AND TRLPANE ALKALOIDS(De Montfort University, 1978-09) McGAW, BRIAN ALEXItem Open Access Iconic conductors for solid state battery systems(De Montfort University, 1979) Hackwood, SusanIn this project, it has been demonstrated that cuprous iodide -sulph.onium iodide double salts, similar to the silver iodide systems previously studied by other workers, are suitable for use in ambient temperature batteries for low current applications. A number of potential solid electrolytes, in which the mobile species is calcium, have also been investigated, and areas for further work have been defined. The relavent section of the thesis is confidential as patent proceedings are possible. The project has involved not only a search for new electrolytes, but also the development of a search strategy. In view of the limitations of direct conductivity measurements on compacted materials, arising from electrical contact problems, considerable use has been made of indirect methods. A critical review of standard electrochemical techniques, often adapted from aqueous methods, has been carried out. This has highlighted shortcomings in the measurements of such para.meters as electronic conductivity, where the self-discharge rate, a pare.meter used by battery technologists, has been found more meaningful than the results obtained from Wagners blocking electrode technique. X-ray diffraction (XRD), and differential thermal analysis (DTA) have been used to disprove the common assertion that the effect of addition of organic dopant materials to silver iodide ha.s the effect of stabilizing the high temperature high conductivity alpha phase. CuI based electrolytes have been found to differ significantly from the AgI analogues in several respects. No simple structural criterion, such as the Group Weighting Coefficient for AgI systems, could be found to predict the effect of addition of organic sulphonium iodide dopants. Battery cells based on Cul did not give the expected thermodynamic open circuit voltage (OCV), and three electrode measurements failed to elucidate this anomaly. The possible involvement of the cupric ion was explored in several ways, including the first application of Auger electron spectroscopy for this type of electrolyte system. The battery discharge characteristics showed a fairly low efficiency, but indirect evidence including the inadvertent involvement of a novel solid state aurous system, pointed to the majority of the anode material being unavailable for reaction.Item Open Access Fundamental study of adhesion problems involving polyethylene and other polymers(De Montfort University, 1979) Konieczko, Michael BoguslawItem Open Access The Hormonal Regulation of Growth of Suspension Cultures of Acer pseudoulatanus L. cells(De Montfort University, 1979-08) Moloney, Maurice MartinThe auxin economy of cell suspension cultures of Acer pseudoplatanus L. has been investigated using physiological and physicochemical techniques. Experiments on the intra- and extra-cellular concentrations of auxins in an auxin-dependent line (OS) of sycamore cells have suggested that endogenous IAA may be a major regulatory factor during a large part of a culture passage. Further experiments with two auxin-prototrophic cell lines (HK and EHM) have revealed that auxin-prototrophy cannot be explained simply in terms of the achievement of higher endogenous IAA levels than are found in auxotrophic lines. This has led to the view that the auxin-requirement of sycamore cells is an initiation-dependency rather than a continuous-dependency on exogenous auxins. This phenomenon has many features in common with current views on the development of tumours in plants. The mechanism which most appropriately accounts for these observations involves an autocatalytic cycle in which endogenous auxins may be both the cause and the effect of certain growth processes. In the whole plant one such process which has been linked to autocatalysis is xylogenesis. Autocatalysis has been implicated in the cell-death hypothesis (Sheldrake, 1973) and requires tha.t IAA is produced as a result of high tryptophan concentrations deriving from the hydrolysed proteins of lysed cells. Studies have been performed on the changes in tryptophan levels in these cells. These indicate that the cell-death hypothesis is inapplicable to this system. This has led to a critical reevaluation of the original evidence in favour of the cell-death hypothesis. It has been the view of certain workers that cell suspension cultures provide an excellent system for the study of growth regulation by phytohormones. This view is based upon the unique properties of suspension cultures which provide an aseptic, homogeneous plant material freed from the more correlative influences found in the whole plant. Advantage has been taken of these features when growth of the cell suspension cultures was analysed mathematically. The cultures were found to provide data with an accuracy and a reproduceability not normally available with whole plants. The relevance of hormonal control of tissue culture growth to whole plants is discussed with particular reference to cambial initiation and differentiation.Item Open Access The Effect of Carrier on the Environmental Stability of Adhesive Joints(De Montfort University, 1979-08) Moloney, Anne CatherineThe effect of incorporating nylon and polyester carriers into epoxide film adhesives has been investigated. Carriers were found to lower· joint strength,' the effect being most severe with a close knitted carrier. The effect of carriers on joint strength durability was evaluated by exposing stressed and unstressed double lap joints at 50 oC and 100% R.H. for various time intervals. Joint strength was adversely affected by this environment. The presence of open carriers did not impair the durability of adhesive joints. Two surface treatment methods were used, these were chromic acid etching and phosphoric acid anodising. The latter was found to give improved durability with the modified epoxide adhesive BSL312. In the case of the nylon epoxide adhesive FM1000 no difference in resultant joint strength was observed between the two pretreatment methods. In an attempt to further clarify the mechanism by which water degrades an adhesive joint, two approaches were used. Firstly, a theoretical calculation was performed, assuming Fickian diffusion through the resin, to predict the water distribution in joints after certain exposure times. Secondly, this was compared with empirical values obtained by a radiotracer technique. The results suggested that water enters a joint primarily by diffusion through the resin and that the kinetics of joint strength degradation are controlled by the availability of water diffusing through the resin. No evidence was found to suggest that the presence of a carrier accelerated the ingress of water into an adhesive joint.Item Open Access The ecology of the Chironomidae (Diptera) in a new eutrophic reservoir(De Montfort University, 1980) Brown, Andrew EdwardThe successional changes in a new. lowland reservoir in Leicestershire, England, were investigated, with particular referece to larvae of the Chironomidae. During the first four years major changes in water chemistry were the result of the different sources of water used to fill the reservoir and the release of nutrients from the inundated terrestrial vegetation. Phytoplankton populations showed erratic changes in species composition and standing crop during the first year of filling. Seasonal fluctuations, similar to those observed at other eutrophic reservoirs, occurred in subsequent years. Chironomid species composition and temporal and spatial variation in the larval populations were investigated. Orth6cladiinae larvae were particularly abundant in mats of algae in shallow water in the second year after filling commenced. This was probably the result of a stable water level, warm weather conditions and high nutrient concentrations. In the third year Chironomus p lumosus and Polypedi tum nubeculosum larvae were numerically do~nant. Populations of these spec~es declined the following year and Tanytarsus species predominated. Temporal changes of the fauna were lnfluenced by climate and the filling regime of the reservoir. Chironamid larvae did not indicate any marked differences in water quali ty be tween the two arms of the reservoir. Populations were generally found to be contagious ly dis tributed. Chironomids in rainbow and brown trout diets were investigated during the first two fishing seasons. The species composition of larvae and pupae in the diets suggested different feeding zones for the two trout species. The behaviour of chironomid larvae and not their numerical abundance determines their occurrence in the diets. The results from this study are discussed in relation to management of the reservoir. Due to the importance of chironomids in trout diet it may be beneficial to base stocking policy on a knowledge of the seasonal population fluctuations of the chironomids.Item Open Access INVESTIGATION OF A DIESEL GAS TURBINE(De Montfort University, 1980-06) Parkin, RobertThe turbocharging of automotive sized two-stroke engines presents a problem to the designer due to the large range of loads and speeds met in service. A mechanically driven blower is usually required to provide a positive pressure drop across the engine at all times, thus providing adequate air for scavenging. The aim of this investigation is to consider a. combination of the two-stroke cycle engine, turbocharger and auxiliary combustion chamber as a prime mover system with a satisfactory torque characteristic and control system. The auxiliary combustion chamber is used for independent control of the turbocharger. To this end various component combinations are described and assessed. Turbochargers of different builds and frame sizes havebeen examined to assess the effects of turbocharger matching. Computerised processing for data acquisition and control has been used. Theoretical work, progressing simultaneously with the experimental programme, has permitted the development of simple computer programs to predict system performance to a good degree of accuracy. The programs are detailed in the appendix. Experimental results have been presented graphically and compared with those predicted by the computer programs. The work has been extended, by computer techni~ues, to investigate the effects of charge cooling, heat exchange, and torque 'tailoring' by the control of engine boost levels. The Diesel Gas Turbine is shown to provide a feasible prime mover system. Significant improvements of power output and torque characteristic have been achieved within constraints of thermal and mechanical loading. The system incurs penalties in specific fuel consumption at low speeds but these are offset, to some extent, by improvements at high speed. The improved torque characteristics; would permit the use of a simpler transmission system, together with the removal of the scavenge blower.Item 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 LeslieItem Open Access AN INVESTIGATION OF THE MECHANISM BY WHICH ALUMINIUM AND OTHER POLYVALENT CATIONS INHIBIT ECCRINE SWEATING(De Montfort University, 1980-12) MICHNIAK, BOZENA B.The aim of this investigation was to elucidate the mechanism by which aluminium and other polyvalent cations reduce sweat output of human and rat eccrine sweat glands. It was shown that sweating in rat plantar eccrine sweat glands could be induced in the anaesthetized animal by systemic administration of carbachol (0,0025-2500 ug/kg) or by local intradermal administration (0.75 µg in 0,01 ml of isotonic saline) of carbachol and methacholine and also by localised heat stress, These effects could all be reduced or abolished by prior administration of atropine ( 100 - 750 ug/kg). Systematically administered isoprenaline (400 µg/kg) was found to be more effective than either adrenaline or noradrenaline at the same dose level in promoting sweating in the foot pads, This effect could be reduced by prior administration of propanolol (800ug/kg). Similar results were obtained with isolated rat sweat gland preparations which produced sweat following administration of carbachol (2 x 10-5) or methacholine (2 x 10-5). These responses were abolished by calcium lack in the bathing medium and atropine (l-5 x 10-5) administration. Aluminium chlorhydrate applied topically to the rat foot pad in concentrations of l to 25% w/v and pH 1.00 - 4,60 was found to be an effective antiperspirant. Lanthanum chloride was found to be more effective on an ionic basis than either aluninium chlorhydrate or zirconium oxychloride, The anhidrotic effect of these three compounds was antagonised by simultaneous application of a range of concentrations of calcium chloride solutions. Other ions studied, e.g. chromium, ferric, barium, magnesium and titanium showed weak onhidrotic action but calcium chloride when applied alone induced slight properspirancy, Human volunteer work using thermal sweating on the dorsal trunk region and emotional in the oxilla suggested that calcium had little or no statistically significant effect on the antiperspirancy of aluminium chlorydrate, but if applied alone exerted, a slight prospirant action in some individuals. However, when sweating was induced by intradermally administered methacholine in the forearm and dorsal trunk, calcium was found to antagonise aluminium anhidrosis and to exert significant properspirancy. The antiperspirant compounds that had previously been found effective in the rat, were tested for their ability to precipitate egg protein at various pH values. It was found that lanthanum, the most effective antiperspirant in the rat model, was also the most effective agent for protein precipitation. Other valent ions and zirconium also produced varying degrees of precipitation. However, divalent ions were totally ineffective. Addition of calcium or magnesium salts in combination with the antiperspirant, increased the amount of precipitated protein significantly. Aluminium chlorhydrate, lanthanum chloride and zirconium oxychloride treated and untreated rat sweat glands were studied using various staining techniques for light and electron microscopy. Untreated human skin sections were examined using only light microscopy. It is proposed that aluminium and other polyvalent cations exert their antiperspirant action by interfering with ductal sodium reabsorption in the lower sweat duct.Item Open Access Thermal stratification in solar storage tanks(De Montfort University, 1981) Eldessouky, Elsayedabd ElhaThe purpose of the work was to investigate the thermal stratification in solar storage containers. Three domestic thermally stratified hot water storage containers were designed with the main object of improving and stabilizing thermal stratification of the stored water as a means of improving the overall efficiency of solar water heating systems. Testing of the three storage containers was carried out under similar conditions and the results showedthat TYPEI storage container behaves as a three-segment stratified system, TYPEII storage container behaves as a two-segment stratified system with a thermocline occupying approximately half of the height of the storage container, and TYPEIII storage container behaves as a two-segment stratified system with a thermocline occupying two thirds of the height of the storage container. It was found that TYPEI storage container, with a LID equal to 3/1, gave the best results in terms of heat collected, and also had the maximum stratification which is the main goal of this study. The effect of each of three flow rates (0.01 kg/Sm2 , 0.015 kg/sm2 , 0.02 kg/sm2 ) on stratification was studied and it was found that the flow rate of 0.01 kg/Sm2 of collector area gave the better result. A low-cost simulator for studying the performance of solar energy storage containers was designed. The design was based on a relatively inexpensive micro-computer linking into a mains power regulator with an 8-bit digital control system. Meteorological data was used to compute radiation income on any inclined plane and the output to the power regulator is controlled by the computed instantaneJus rate of energy gain from the collector system undergoing simulation.A comparison has been made between some of the experimental and theoretical results for mE I storage container. The theoretical prediction was based on two mathematical IOOdels of Duffie and 2 44 Beckman , and Close • A computer system model has been developed to assist in the design of a solar water heating system.Item Open Access Bioavailability studies on orally administered, oily suspensions of drugs.(De Montfort University, 1981) Alhammami, Omran Moosa Omran.