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  • 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.
11

Photo-conduction in semi-conductors

Caldwell, John Bell January 1948 (has links)
This thesis is largely concerned with the phenomenon of photo-conduction in micro-crystalline layers of lead sulphide, antimony sulphide and thallium sulphide. All the materials studied are semi-conductors, either excess or defect.
12

Integrated service selection, pricing and fullfillment planning for express parcel carriers - Enriching service network design with customer choice and endogenous delivery time restrictions

Martin, Florian, Hemmelmayr, Vera, Wakolbinger, Tina January 2019 (has links) (PDF)
Express parcel carriers offer a wide range of guaranteed delivery times in order to separate customers who value quick delivery from those that are less time but more price sensitive. Such segmentation, however, adds a whole new layer of complexity to the task of optimizing the logistics operations. While many sophisticated models have been developed to assist network planners in minimizing costs, few approaches account for the interplay between service pricing, customer decisions and the associated restrictions in the distribution process. This paper attempts to fill this research gap by introducing a heuristic solution approach that simultaneously determines the ideal set of services, the associated pricing and the fulfillment plan in order to maximize profit. By integrating revenue management techniques into vehicle routing and eet planning, we derive a new type of formulation called service selection, pricing and fulfillment problem (SSPFP). It combines a multi-product pricing problem with a cycle-based service network design formulation. In order derive good-quality solutions for realistically-sized instances we use an asynchronous parallel genetic algorithm and follow the intuition that small changes to prices and customer assignments cause minor changes in the distribution process. We thus base every new solution on the most similar already evaluated fulfillment plan. This adapted initial solution is then iteratively improved by a newly-developed route-pattern exchange heuristic. The performance of the developed algorithm is demonstrated on a number of randomly created test instances and is compared to the solutions of a commercial MIP-solver. / Series: Schriftenreihe des Instituts für Transportwirtschaft und Logistik - Supply Chain Management
13

Biochemical studies of the synaptic protein otoferlin

Meese, Sandra 17 February 2015 (has links)
No description available.
14

The transmission of classical and patristic texts in late Anglo-Saxon and early Norman England

Castles, Nicola Jane January 1993 (has links)
This thesis consists of a general introduction to the historical and palaeographical background to the subject of the transmission of Classical and Patristic texts in late Anglo-Saxon and early Norman England, followed by five chapters each dealing with a classical or patristic author. Each chapter lists the information we have available on manuscripts containing the author's work, and conclusions are drawn as to the transmission of that work. In the case of five texts, Persius, Satirae; Augustine, Enchiridion; Gregory, Cura pastoralis and Moralia and Isidore, Synonymar portions of each MS are taken and compared in detail with each other and with the modern printed edition, and a stemma is constructed on the basis of evidence thus obtained. A conclusion draws together the information on the transmission of such manuscripts throughout the eighth to twelfth centuries. There are two appendices: the first contains brief notes on texts by Classical and Patristic authors of which there are not enough copies to form stemmata, while the second takes the form of a short analysis of the use of the letter k in the margins of some insular MSS studied. There are also indices nominum et manuscriptorum. The work is divided into two volumes after Chapter Three.
15

The geology of the Cairnsmore of Fleet granite and its environs, southwest Scotland

Cook, David R. January 1976 (has links)
The thesis is divided into three parts relating to (i) the sedimentary rocks, (ii) the granite and minor intrusive rocks and (iii) the Fleet orefield. The Sedimentary successions around the Cairnsmore of Fleet pluton are divided into two new formations; the Craignell and Knockeans Formations. The former is sub-divided into three facies based upon a geochemical classification of greywackes undertaken using cluster analysis. Facies boundaries within the Craignell Formation and interformational boundaries between this formation and the underlying Moffat Shales and the younger Knockeans Formation are all probably diachronous. Tectonically derived structures within the sedimentary rocks are correlated with those reported from areas elsewhere within the Southern Uplands. Certain structures are, however, unique to this area and some may be related to the emplacement of the Fleet pluton. Mineralogical zones within the extensive thermal aureole surrounding, the granite are described and correlated with previously published facies of contact metamorphism: albite-epidote hornfels, hornblende hornfels and K-feldspar-cordierite hornfels facies. Petrological facies within the granite are described and the classification thus produced endorsed geochemically with the aid of cluster analysis. Chemical trends in separated minerals, are correlated with bulk chemical variation in the granite which is outlined using correlation, regression and trend surface analyses. Geo-chemical and petrological data are compared with published experimental mineralogical studies. Minor intrusive rocks are similar in composition to those occurring throughout Galloway with two notable exceptions of more basic composition. The chemistry of the minor of the Fleet pluton are described the western margin to the Fleet pluton are described in detail for the first time. A distinct mineralogical zoning pattern is spatially related to the granite and consists of an inner zone within the pluton and generally close to the contact in the country rocks, containing dominant chalco-pyrite, pyrrhotite, pyrite and high temperature ores such as pentlandite and arsenopyrite with a quartzose gangue. Outer zones contain veins of sphalerite and mixed carbonate and quartz gangue, and give way to an outermost zone of galena with carbonate and barytes gangue. Geochemical studies on separated ore minerals has enabled the distinction of ores from particular zones and give an indication of their relative temperatures of formation. Wallrock alteration is described and is generally consistent in its characteristics with the changing mineralogy of the vein deposits. The ore deposits are related to the geophysically predicted granite batholith beneath the Southern Uplands, but more specifically to the Fleet pluton. The mineralogy and geochemistry of the deposits are consistent with this, but geochronological studies from other areas suggest that the ores may be at least 40 my younger than the granite. A hypothesis for the origin of the hydrothermal deposits is presented and is based upon data outlined above.
16

Presentations for subsemigroups of groups

Cain, Alan James January 2005 (has links)
This thesis studies subsemigroups of groups from three perspectives: automatic structures, ordinary semigroup presentations, and Malcev presentaions. [A Malcev presentation is a presentation of a special type for a semigroup that can be embedded into a group. A group-embeddable semigroup is Malcev coherent if all of its finitely generated subsemigroups admit finite Malcev presentations.] The theory of synchronous and asynchronous automatic structures for semigroups is expounded, particularly for group-embeddable semigroups. In particular, automatic semigroups embeddable into groups are shown to inherit many of the pleasant geometric properties of automatic groups. It is proved that group- embeddable automatic semigroups admit finite Malcev presentations, and such presentations can be found effectively. An algorithm is exhibited to test whether an automatic semigroup is a free semigroup. Cancellativity of automatic semigroups is proved to be undecidable. Study is made of several classes of groups: virtually free groups; groups that satisfy semigroup laws (in particular [virtually] nilpotent and [virtually] abelian groups); polycyclic groups; free and direct products of certain groups; and one-relator groups. For each of these classes, the question of Malcev coherence is considered, together with the problems of whether finitely generated subsemigroups are finitely presented or automatic. This study yields closure and containment results regarding the class of Malcev coherent groups. The property of having a finite Malcev presentation is shown to be preserved under finite Rees index extensions and subsemigroups. Other concepts of index are also studied.
17

The dispersive action of concentrated salts on collagen

Candlish, John Kerr January 1963 (has links)
1. The literature concerning the dispersion off collagen by concentrated salt solutions has been reviewed; the literature concerning the reconstitution off native type collagen fibres has boon briefly reviewed, as has recent literature on the properties off the substrate for this work, calf skin collagen. 2. It has been shown that the dispersion off collagen by KI and CaCl2, involves, above a threshold concentration off salt, a highly reversible denaturation of the protein. 3. This denaturation has been shown to result in the dissociation off collagen into three subunits at various concentrations off salt. It has been proposed on the basis of these fractionations that the collagen employed consists off a population off units with varying degrees off resistance to depolymerisation, and therefore varying degrees off intramolecular cohesion. 4. It is considered that the available evidence favours as the mechanism off denaturation the reorientation off water in the solvent by KI or CaCl2 rather than the direct binding off salt molecules or ions to the protein. 5. Collagen fibres thermally reconstituted in the presence of various physiological substances have been shown to have different degrees of resistance to re-dispersion by KI and urea. Substances which appear to render the collagen more resistant are some anions, all amino acids tested, and L-ascorbic acid. 6. The effect of ascorbic acid and related substances on the resistance to re-dispersion of thermally reconstituted collagen has been studied in some detail and it is considered that the stabilising effect of this substance is due to its ionising enol grouping. The literature concerning a possible interaction of L-ascorbic acid with collagen in vivo has been reviewed and it has been proposed that the acid may have both an intracellular and extracellular function in repair tissue. 7. It has been demonstrated that non-protein nitrogen can be prepared from collagen in a number of ways, some of which do not involve extremes of pH or temperature throughout the entire manipulation of the collagen, Evidence for and against the assigning of a specific biological function to this non-protein nitrogen has been discussed.
18

The development of predation in cats

Caro, T. M. January 1979 (has links)
This study is concerned with some of the processes that occur during the development of behaviour, and these are examined in the context how predatory behaviour develops in domestic cats, initially some of the problems that have beleaguered the study of behavioural development are examined and current issues in this field ae outlined. The experimental design of the study, the definitions of recorded behaviour and the methods of data analysis are then discussed. The study then focusses on the multiple effects that experiences in development can have on adult behaviour. It shows that cats were better able to catch prey as adults if they had had experiences of it as kittens, that cats specialized on the type of prey with which they had had prior experiences, and that little generalization to other prey types occurred in cats with experience of one prey type. Several other factors likely to affect adult predatory behaviour were than examined. Both the presence of the mother during kittens' exposure to prey, and experience of prey as adults were found to improve adult predatory competence. Object play had no effect on predatory behaviour. The study went on to relate the development of social play in kittens to the development of predatory behaviour. Some aspects of play became more associated with predatory behaviour aspects grew older, others less so. Different patterns of play appeared to increasingly come under separate types of control as kittens developed. One of the factors affecting the development of predatory behaviour, the effect of the mother, was then examined in detail. Some of the ways in which mothers encouraged their offspring to interact with prey were outlined together with the ways that offspring responded to the mother's predatory behaviour. Finally, the relationship between predatory behaviour in kittens and their subsequent predatory behaviour as adults was investigated. Many aspects of kitten predation were found to correlate with adult predatory activity. Some individuals that were poor predators as kittens showed competent predatory behaviour as adults. The implications of those findings were discussed in relation to the development of predatory behaviour, the development of play and the timing of events in kitten ontogeny.
19

Morfometria do processo odontóide em espécimens obtidos na cidade do Recife

Limeira do Santos Neto, Francisco January 2007 (has links)
Made available in DSpace on 2014-06-12T16:28:31Z (GMT). No. of bitstreams: 2 arquivo5644_1.pdf: 4391035 bytes, checksum: 187ae162cac5b6548c286ff025a2af9f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / As fraturas do processo odontóide aumentam sua freqüência a partir da idade adulta, chegando a ser a fratura mais freqüente da coluna vertebral após os 80 anos de idade. Seu tratamento exige conhecimento detalhado da anatomia vertebral para se obter uma fixação adequada e menor imobilização pósoperatória, reduzindo a morbidade e a mortalidade. O objetivo do estudo foi a mensuração direta do processo odontóide e a sua relação com a vértebra C2 em cadáveres adultos. Foram analisadas 64 vértebras C2 de cadáveres adultos, pertencentes ao acervo do Departamento de Anatomia do Centro de Ciências da Saúde da Universidade Federal de Pernambuco, no período de outubro de 2006 a fevereiro de 2007. Sendo 32 vértebras de indivíduos do gênero masculino e 32 do feminino, que foram submetidas mensurações diretas com paquímetro de precisão para altura do odontóide e suas relações com o corpo de C2, os diâmetros coronais e sagitais maiores e menores e sua angulação em relação ao corpo de C2 através de radiografias. As dimensões dos processos odontóide são variáveis, sendo a altura média no grupo feminino igual a 14,16 ± 1,10mm e no masculino igual a 15,21 ± 1,15mm. O diâmetro transverso menor foi 8,81 ± 0,47mm para o grupo feminino, enquanto que foi 9,38 ± 0,84mm para o masculino. O ângulo de inclinação variou de 0 a 26º no sentido posterior para os dois grupos. Foram observados dois grupos morfologicamente distintos de processo odontóide classificados de base estreita e corpo alargado e base larga e corpo estreito. Pode-se concluir que a morfometria, morfologia e a angulação dos processos odontóides são variáveis: a altura média do processo odontóide está abaixo de 15mm; o diâmetro transverso do processo odontóide é menor do que o ântero-posterior; as médias das circunferências do corpo do odontóide são significantemente maiores do que as da base, tanto no tipo pediculado quanto no séssil. A fixação do odontóide exige planejamento tomográfico prévio
20

Posterior atlantoaxial fixation: A cadaveric and fluoroscopic step-by-step technical guide

Baaj, AliA, Sattarov, Kamran, Skoch, Jesse, Abbasifard, Salman, Patel, AparS, Avila, MauricioJ, Walter, ChristinaM January 2015 (has links)
UA Open Access Publishing Fund / Background: Atlantoaxial surgical fixation is widely employed treatment strategy for a myriad of pathologies affecting the stability of the atlantoaxial joint. The most common technique used in adults, and in certain cases in children, involves a posterior construct with C1 lateral mass screws, and C2 pars or pedicle screws. This technical note aims to provide a step‑by‑step guide to this procedure using cadaveric and fluoroscopic images. Methods: An embalmed, human, cadaveric, specimen was used for this study. The subject did not have obvious occipital‑cervical pathology. Dissections and techniques were performed to mimic actual surgical technique. Photographs were taken during each step, and the critical aspects of each step were highlighted. Fluoroscopic images from a real patient undergoing C1/C2 fixation were also utilized to further highlight the anatomic‑radiographic relationships. This study was performed without external or industry funding. Results: Photographic and radiographic pictures and drawings are presented to illustrate the pertinent anatomy and technical aspects of this technique. The nuances of each step, including complication avoidance strategies are also highlighted. Conclusions: Given the widespread utilization of this technique, described step‑by‑step guide is timely for surgeons and trainees alike.

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