• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 41
  • 8
  • 8
  • 8
  • 8
  • 5
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Medieval Jewish exegesis of the Book of Lamentations

Anderson, Deborah January 2004 (has links)
This thesis is in two parts. The first part consists of translations of five medieval commentaries on the Book of Lamentations composed by Rashi, Yosef Kara, and Abraham ibn Ezra. While the Rashi and ibn Ezra commentaries are available in translation, the two written by Yosef Kara are not. These two Kara commentaries contain transliterated Medieval French dialects that are difficult to translate, at least in part, because the copyists did not appear to understand what they were copying. The translation of these texts has, therefore, begun the long task of trying to develop a system by which Kara's Medieval French explanations may be understood. The initial findings are recorded in the translations. The second part of this work concerns the development of a method by which these translations may be better understood. A comparison of eight verses from the Book of Lamentations was made, and a method based on sociolinguistic and literary theory was applied, to attempt an explanation of the use of peshat method of exegesis as a function of meaning.
2

A geological investigation of a tertiary intrusive centre in the Vididalur-Vatnsdalur area, Northern Iceland

Annells, Richard Newton January 1968 (has links)
This thesis is an account of an investigation into the structure, petrology and mineralogy of a small Tertiary intrusive centre in the Vididalur-Vatnsdalur area near the north coast of Iceland. The area concerned lies in the Tertiary area west of the neovolcanic zone. In upper Tertiary times the extrusion of flood basalts in the area studied was locally interrupted by the building of a central volcano characterized by distinctive basalts, andesites and pyroclastics, some of which interfingered with contemporaneously extruded flood basalts. The first episode of this central volcanic activity, of which only the top is seen in the area studied, was subsequently buried by the transgressing flood basalts, and slow downsagging occurred in parts of the area along the prevailing north to north-northeast fracture system. A second central volcanic episode produced basalt, andesite and rhyolite extrusions and some pyroclastics in the northeastern part of the area following the flood transgression. Injection of thin basic dykes proceeded parallel to the two phases of central activity and continued during a final episode in which thin pale grey basalts similar to the Lower Pleistocene to Recent flows elsewhere in Iceland were extruded on to the irregular central volcano land surface. Two phases of intrusive activity proceeded parallel to the extrusive activity, the older More deeply eroded First Phase products being emplaced in the time interval during which the older flood basalts buried the newly extruded earlier central volcano lavas. A consecutive Second Phase of intrusive activity proceeded simultaneously with the second central volcanic episode and its less deeply eroded products show many similarities to the contemporaneous extrusions. These First and Second Phase intrusions are probably the upper apophyses of larger bodies concealed at depth. The intrusions which form the main part of the study are concentrated about an intrusive/extrusive centre in northern Vididalsfjall, and consist of coarse- and fine-grained basic to acid series, ranging in the First Phase from olivineeucrites (bytownite cumulates) through gabbros (labradorite cumulates), hybrid diorite and intermediate-acid hybrid types to acid granophyres. The First Phase was initiated by the intrusion of the eucrites and a dense swarm of tholeiitic cone-sheets centred on a focus about 5 km below northern Vididalsfjall. Commingling of the simultaneously available diorite and granophyre magma later in the First Phase resulted in the formation of small volumes of acid-intermediate hybrid rocks. The Second Phase intrusive activity is expressed as small high-level intrusions and began with a new supply of olivinetholeiite magmas which was injected along cone-fractures to form a late set of high-level cone-sheets centred on a focus about 2 km below northern Vididalsfjall. Cogenetic bytownite cumulates were emplaced as small high-level intrusions, but coarse-grained rocks and acid rocks of Second Phase age are rare in the area studied. iii. A broad aureole of hydrothermally altered rocks surrounds northern Vididalsfjall and smaller alteration zones surround other smaller regions cut by vents and intrusions; these altered and injected zones are taken to represent the eruptive channels at the core of the Vididalur-Vatnsdalur volcano. The intrusive rocks are all plagioclase-pyroxene-ore assemblages with or without olivine, alkali feldspar and quartz, and the First Phase types show a gradation from basic rocks bearing calcic plagioclase and magnesian augite to acid rocks containing sodic plagioclase anorthoclase and ferrian augite. The Second Phase rocks show broad petrographic similarity to those of the First Phase but coarse-grained intermediate and acid types are not found, and the basic rocks are richer in olivine than corresponding First Phase types. All the rocks examined show textural and mineralogical evidence of a high degree of fractionation and rapid final cooling at high crustal levels; the plagioclase of phenocryst rims and groundmasses is in a high-temperature structural state, the calcium-rich pyroxenes have immature exsolution textures, the olivines are strongly zoned and interstitial glassy or salic material is abundant. Many of the acid minor intrusions contain tridynlite paramorphed by quartz. Chemical analyses of 14 Vididalur-Vatnsdalur rocks show that they are low in alumina, combined alkalis and magnesia, and are relatively rich in iron, and titania, as are other Tertiary Icelandic tholeiites, with soda present in greater quantity than potash. The analyses of these basic intermediate and acid rocks fit on the iron-enriched trend for tholeiites (Nockolds a.nd AlIen, 1956) which suggests that the First and Second Phase sequences may have originated by -contiriuous fractionation of basic tholeiitic uuterinl. However there is little direct evidence of a tholeiite fractionation origin for the First Phase granitic acid rocks, and the presence of a few small veins of remelted acid material at some localities casts doubt on a fractionation origin for these granophyres and granites of the Vididalur-Vatnsdalur area.
3

The determinants of competitive advantage : a critical appraisal

Allan, Andrew C. January 1991 (has links)
The thesis deals with the means whereby a firm can gain a competitive advantage over its rivals. After considering how this issue is dealt with in the management literature, the thesis focuses on two possible routes to competitive advantage. The first is largely internal to the firm, and concerns the design of managerial contracts to provide managers with the incentives to act in the best interests of shareholders. The second route is external, involving strategic market moves in relation to rival firms. These two possible routes to competitive advantage are appraised in light of recent theoretical developments in 1principal-agent analysis the internal route, and the new industrial economics the external route. The final section of the thesis is empirical and deals with the share price experience of the top 100 U. K. companies since 1970. The econometric notion of cointegration is employed to test for the existence of sustained competitive advantage. The tentative conclusion reached is that while companies may be able to achieve a sustained competitive advantage, the compensation contracts employed have not been a successful means of obtaining such advantage. The suggestion is that external routes to competitive advantage might be more effective.
4

The stability of particle-like solutions of some non-linear field equations

Anderson, David Lessells Thomson January 1969 (has links)
The object of this thesis is to examine the stability of particle-like solutions of the nonlinear field equation ▽2Ψ - 1/c2 δ2Ψ/δt2 = K2Ψ –μ2 ΨΨ*Ψ+λ(ΨΨ*)2Ψ with the particular form of time-dependence Ψ = φ (r) e − lwt Initially our interest is concentrated on the case λ = 0. We begin the analysis by finding spherically symmetric particle-like solutions, and then examining the stability of the lowest-order solution by first- order perturbation theory. Direct perturbation methods are then considered. This solution is found to be highly unstable whether it is time-independent (ω = 0) or not (ω ≠ 0). The more general case λ ≠ 0 is next discussed. Particle-like solutions are found to exist in this case for -∞ < λ (K2 - w2/c2) μ4 < 3/16 On examining the stability of the lowest-order solutions of this generalised field equation, it is found that for correct choice of the field parameters stable time-dependent solutions can exist, some of which can also have the attractive feature that their energy density is positive definite. We conclude by considering some methods of extending the theory.
5

Christian and Marxian conceptions of history in the twentieth century : an evaluation of certain twentieth century interpretations of the Marxian conception of history

Anderson, Walter Wallace January 1965 (has links)
No description available.
6

Use of inorganic carbon in the photosynthesis of aquatic macrophytes and microalgae

Allen, E. Dale January 1977 (has links)
A broad range of aquatic plants has been examined by means of three experimental techniques for the purpose of describing their abilities to use the different forms and concentrations of inorganic carbon which may be presented to them. Experiments were carried out on macrophyte shoots or algal suspensions in a specially designed apparatus under uniform conditions of light (560 ?Einsteins m-2 s-1) and temperature (20&deg;C) while measuring the rate of oxygen production, and the rate of carbon uptake 3S determined indirectly by pH measurements. Kinetic experiments showed that macrophytes had more diffusive resistance to CO2 uptake than microalgae; that microalgae had a high affinity for CO2 and HCO3 whereas the macrophytes, including previously established bicarbonate users, had high affinities for CO2 only. The ratio of [HCO3] to [CO2] needed to produce the same rate of photosynthesis ranged from less than 1 in two of the microalgae to more than 100 in two macrophytes, implying a gradation in capability for bicarbonate use. Results of experiments at constant with varied pH showed that, over the range 7.4 to 9.0, net photosynthesis of the macrophytes was primarily dependent upon [CO2] in a given CT concentration but that of Anabaena cylinrica and Chlorella emersonii was not; their rates only became pH-dependent above pH 9.5. Bicarbonate use by macrophytes above pH 9 became apparent if the [CT] was high enough. The question of bicarbonate use by any specie depends upon the concentration of bicarbonate in the bathing solution, that species' affinity for bicarbonate and its bicarbonate compensation point. Using the pH-drift technique, a method is described for distinguishing CO2 and HCO3 compensation points. With this method, CO2 compensation points were determined as 0.9 muM for Cosmarium botrytis, 4.5 muM for Elodea Canadensis, 5.5 muM for Eurhynchium rusciforme, and 8 muM for Fontinalis antipyretica; HCO3 compensation points ranged from 0.05 mM in Cosmariuni to, respectively, 0.9, 0.95, and 3.3 mM in the macrophytes. From evidence from these three types of experiment, bicarbonate users and non-users do not exist as such but there is a graded capacity to use bicarbonate in which strong and weak users can be distinguished. Their poor affinity for bicarbonate means that most macrophytes can barely photosynthesise with this source at natural alkalinities when pH rises above 9. Macrophytes are largely CO2 dependent and, since CO2 is rarely saturating, they become pH- dependent. The photosynthetic activities of the plants in a lake, particularly those with a high affinity for bicarbonate can reduce the CT concentration below the air-equilibrium level. The resulting rise in pH, and at times precipitation of marl, causes a sever reduction in the free CO2 concentration which the weak users of bicarbonate rely on. It is suggested that competition for carbon arising from variations in alkalinity and from free CO2 depletion constitute an important factor in determining the composition of the plant community in lakes, particularly the macrophytes, and these plants can serve as indicators of the long-term carbon status of a lake.
7

Event-related potential studies of explicit retrieval from memory

Allan, Kevin January 1997 (has links)
In six studies, Event-Related Potentials (ERPs) were employed to investigate the neural basis of conscious (explicit) retrieval from long term memory. The studies provide the first detailed reports of ERP effects associated with explicit retrieval on tests of word-stem (e.g. TRE) cued recall and stem completion. The relationship between the cued recall ERP effects and those previously observed on other tests of memory was also investigated. This was done by directly contrasting ERP correlates of explicit retrieval on the cued recall and recognition memory tasks. Two features of the cued recall and recognition memory ERP effects were found to be highly similar: ERP effects for each task were comprised of parietally and frontally distributed components which differed, as a function of task, only in two respects. First, the parietal effect for cued recall appeared to be somewhat delayed in onset latency relative to that for recognition memory. Second, the hemispheric asymmetry of the frontal effect for cued recall was less marked than that for recognition memory. The two ERP components were interpreted in terms of processes contributing to the recollection of previous episodes in which words were presented for study. A basic distinction between retrieval and post-retrieval processes was invoked to provide a functional account for the two components. The parietal component was related to retrieval processing associated with 'old/new' judgements. The frontal component was related to post-retrieval processing of retrieved information, which may be more under strategic control, and therefore sensitive to factors extrinsic to those affecting retrieval success per se. In conjunction with the findings of other ERP studies of long term memory, the present results suggest that similar electrophysiological and cognitive processes may be involved in retrieval and post-retrieval processing on a wide range of memory tasks. It is proposed that, under certain conditions, a common feature of these tasks may be the requirement to engage working memory, to monitor explicit retrieval processing.
8

An investigation into the aesthetic and psychological effects of the soiling and cleaning of building facades

Andrew, Christopher A. January 1994 (has links)
As buildings age biological and non biological soiling accumulates on their facades. Soiling changes the visual appearance of buildings. This thesis investigates the aesthetic and perceptual changes which take place as a result of the accumulation of soiling. A series of experiments and surveys were conducted to investigate the effects soiling had on aesthetic and perceptual judgements of buildings. A multiple sorting procedure using photographs of buildings, revealed that both an aesthetic evaluation and soiling levels were important ways in which the buildings were conceptualised. A second study comparing photographs of architecturally similar buildings before and after stonecleaning had taken place, revealed large shifts in the evaluation of buildings following cleaning as measured by semantic differentials. Changes in evaluation were found to be dependent on the nature and outcome of the cleaning process. Buildings were also consistently perceived to be younger following cleaning. Surveys amongst residents of cities which had undergone major stonecleaning programmes revealed an awareness of this activity in line with theories of urban perception. Attitudes towards stonecleaning programmes was found to be generally favourable. A survey conducted amongst architects showed the complex range of aesthetic and perceptual effects which soiling and cleaning has on buildings. The surveys conducted amongst both the general public and architects revealed that while cleaned buildings were generally seen to be aesthetically more pleasing than heavily soiled ones, there were some situations where soiling could enhance the aesthetic appearance of buildings. A further study involving ratings of buildings which varied in terms of soiling was therefore conducted which further clarified the role of soiling in aesthetic judgements. Drawing on research in experimental and environmental aesthetics, as well as data from the reported experiments and surveys a model is proposed which relates soiling level to facade complexity and aesthetic evaluation.
9

The mechanical properties of fish myotomal muscle

Altringham, John Derek January 1981 (has links)
CHAPTER 1 A brief introduction is given to the structure, biochemistry and electrophysiological and mechanical properties of fish muscle. CHAPTER 2 1. The neuromuscular end plates and preterminal axons of cod, Gadus morhua, fast myotomal muscle were stained for cholinesterase activity. 2. The number of end plates per fibre on superficial fast fibres (17.88 +/- 2.13, mean +/- 1 S.D.) was significantly higher than that of deep fast fibres (14,79 +/- 2.48, P<< 0.001). A small degree of multi-terminal innervation was noted. The end plates showed a great variety in structure and size. 3. Fast muscle contains fibres with a wide range of diameters (20-240 μm). However, no correlation was found between the number of end plates per fibre and fibre diameter. CHAPTER 3 1. The force-velocity characteristics of threads of natural actomyosin, and purified component proteins, from dogfish fast and slow muscle, and rabbit fast skeletal and cardiac muscle have been investigated. 2. Maximum isometric tensions were around 30-70 g cm-2. The time taken to reach full tension after activation with ATP was 2-8 min. 3. Force-velocity curves obtained could be fitted to a linear form of Hill's equation (1938). In common with intact and skinned fibre studies, points below 0.7 P0 were found to lie on a straight line. 4. Maximum contraction velocities were around 10-2 Ls-1, 2-3 orders of magnitude lower than those of intact muscle fibres. 5. The relative velocities of the different thread types do not reflect those of the corresponding muscles, on the basis of measurements on intact fibres, and on measurements of actomyosin/myofibrillar ATPase activities. 6. It is concluded that filament formation, geometry and packing, and not differences in cross bridge cycling rates, largely determine the observed properties of actomyosin threads. CHAPTER 4 A description of the apparatus used to study the isometric and isotonic properties of skinned fibres is given, together with the methods and protocol used in Chapters 5-7. CHAPTER 5 1. The pCa-tension relationship of cod, Gadus morhua, and dogfish, Scyliorhinus canicula, fast and slow skinned fibres isolated from the myotomal muscles was investigated. 2. Maximum isometric tensions were 1.9 +/- 0.12 (mean +/- 1 S.E.) (fast) and 0.85 +/- 0.10 (slow) for cod fibres, and 1.87 +/- 0.09 (fast) and 0.84 +/- 0.04 (slow) for dogfish 3. Sigmoid pCa-tension curves were obtained for all fibre types. Values for the half maximally activating [Ca2+], and n, the minimum number of Ca2+ binding sites involved in activation, were calculated: Thus, the minimum number of Ca2+ binding sites in cod is two, in dogfish, four. In both fish, greater cooperativity is exhibited by the fast muscle. CHAPTER 6 1. Force-velocity curves were derived from fast and slow skinned fibres isolated from cod and dogfish myotomal muscles. 2. The extrapolated V and the constants a and b were calculated max from a linear form of Hill's equation: 3. These results are discussed with reference to previous studies of the P-V relationship in amphibian and mammalian muscle. The relationship between a/P₀ and efficiency, and its bearing on the present results is discussed.4. Velocity transients showed a small departure from linearity in all experiments, with velocity decreasing continuously during release (usually < 25% over the first 250 ms after release). This is a feature common to many previous experiments on skinned and intact fibres. The decrease in velocity during release was particularly marked in cod slow fibres. Similar results have been reported in amphibian slow muscle. CHAPTER 7 1. Contraction velocity at low loads was studied in dogfish fast fibres during maximal and submaximal activations. 2. The velocity of contraction during the second 50 ms interval after the onset of release was reduced significantly at low [Ca2+], The shape of the velocity transient was found to be dependent on [Ca2+]. The rate of decrease of velocity was greater in submaximal than in maximal activations. 3. A brief review of previous studies on the dependence of Vmax on max [Ca2+] is given. 4. The results are discussed in the light of recent evidence for length dependent changes in the contractile system. Possible mechanisms for a Ca2+ and length dependent inactivation process are considered. CHAPTER 8 The major outstanding problems are stated, and suggestions are made for further work which may give a greater insight into the molecular events underlying contraction in fish muscle.
10

Phase separation spinning of polypropylene fibers

Andrade, Carlos A. January 1972 (has links)
Polypropylene fibers were spun from solutions of different polymer contents undergoing phase separation. The range of concentrations used was 25 to 60 wt. % polypropylene. The solvent used was naphthalene. After the naphthalene was extracted from the fibers using diethyl ether the fiber's properties were measured. Deniers and diameters of the fibers varied inversely with the spinning draw ratio. The fibers had void fractions ranging from 0.20 to 0.70. The porosity of the fibers was inversely proportional to the polymer contents of the spinning solution. Tenacities and moduli ranging from 1.5 to 8.5 and from 6 to 17 grams per denier, respectively, were measured after the fibers were cold drawn 4/1. These values varied directly with spinning draw ratio. Percent elongation at break of fibers spun from solutions of polymer contents greater than 35 wt. % polypropylene varied inversely with draw ratio. Fibers spun from solutions of less are 35 polymer contents showed elongations at break which varied directly with draw ratio for draw ratios of less than about 1500. For higher draw ratios and inverse relationships were observed. The fibers exhibited good hand bulk, and self-coiling and crimping characteristics. / Master of Science

Page generated in 0.0287 seconds