1000 resultados para Contact manifold


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The thesis traces the interaction of the Goroka Valley people with European and coastal New Guinean intruders during the pacification stage of contact and change. In this 15 year period the people moved from a traditional subsistence culture to the threshold of a modern, European-influenced technological society. The contact experiences of the inhabitants of the Valley and the outsiders who influenced them are examined, using both oral and documentary sources. A central theme of this study is the attempts by Europeans and their coastal New Guinean collaborators to achieve the pacification of a people for whom warfare has been described as 'the dominant orientation'. The newcomers saw pacification as being inextricably linked with social, economic and religious transformation, and consequently it was pursued by patrol officers, missionaries and soldiers alike. Following an introductory chapter outlining the pre-contact and early-contact history of the Goroka Valley people, there is a discussion of the causes of tribal fighting in Highlands communities and two case studies of violent events which, although occurring beyond the Goroka Valley, had important consequences for those who lived within its bounds. The focus then shifts to the first permanent settlement of the agents of change -initially these were coastal New Guinean evangelists and policemen - and their impact on the local people. A period of consolidation is then described, as both government and missions established a permanent 'European presence in the Valley'. This period was characterised by vigorous pacification coupled with the introduction of innovations in health and education, agriculture, technology, law and religion. The gradual transformation of Goroka Valley society as a result of the people's interaction with the newcomers was abruptly accelerated in 1943, when many hundreds of Allied soldiers occupied the Valley in anticipation of a threatened Japanese invasion. Village life was disrupted as men were conscripted as carriers and labourers and whole communities were obliged to grow food to assist the Allied war effort. Those living close to military airfields-and camps were subject to Japanese aerial attacks and the entire population was exposed to an epidemic of bacillary dysentery introduced by the combatants. However the War also brought some positive effects, including paradoxically, the almost total cessation of tribal fighting, the construction of an ail-weather airstrip at Goroka which ensured its future as a town and administrative and commercial centre, and the compulsory growing of vegetables, coffee, etc, which laid the foundations for a cash economy and material prosperity. The final chapter examines the aftermath of military occupation, the return of civil administration and the implementation of social and economic policies which brought the Goroka Valley people into the rapid-development phase of contact. By 1949 Gorokans were ready to channel their aggressive energies into commercial competitiveness and adopt a cash-crop economy, to accept the European rule of law, to take advantage of Western innovations in medicine, education, transport and communications, to seek employment opportunities at home and in other parts of the country and to modify their primal world view with European religious and secular values. A Stone Age people was in process of being transformed into a modern society.

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Investigates the relationship between painting and photography, with a special focus on techniques using large contact negatives and digital applications. The thesis is comprised of a written exegesis that contextualises and informs upon an exhibition of photographic and digital inkjet montages. It discusses the theoretical and structural issues underpinning the conceptual basis of the research and elaborates upon the applications and processes involved in producing each exhibited image.

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The experiments reported in this thesis investigated the visual information used by observers to judge the time-to-contact (TTC) of approaching objects. The results provide support for the proposition that TTC judgements are based on retinal image expansion rate and observers' prior experience with the objects.

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This research investigated the benefits of children's contact with nature as perceived by adult educators. It was found that contact with nature is perceived to: increase self-confidence and self-esteem; provide opportunities to experience mystery, privacy, and sensory engagement; connect children with school; and accommodate different learning styles and abilities.

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Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to investigate correlations between the molecular changes and postcuring reaction on the surface of a diglycidyl ether of bisphenol A and diglycidylether of bisphenol F based epoxy resin cured with two different amine-based hardeners. The aim of this work was to present a proof of concept that ToF-SIMS has the ability to provide information regarding the reaction steps, path, and mechanism for organic reactions in general and for epoxy resin curing and postcuring reactions in particular. Contact-angle measurements were taken for the cured and postcured epoxy resins to correlate changes in the surface energy with the molecular structure of the surface. Principal components analysis (PCA) of the ToFSIMS positive spectra explained the variance in the molecular information, which was related to the resin curing and postcuring reactions with different hardeners and to the surface energy values. The first principal component captured information related to the chemical phenomena of the curing reaction path, branching, and network density based on changes in the relative ion density of the aliphatic hydrocarbon and the C7H7O+ positive ions. The second principal component captured information related to the difference in the surface energy, which was correlated to the difference in the relative intensity of the CxHyNz+ ions of the samples. PCA of the negative spectra provided insight into the extent of consumption of the hardener molecules in the curing and postcuring reactions of both systems based on the relative ion intensity of the nitrogen-containing negative ions and showed molecular correlations with the sample surface energy.

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This paper presents a novel optical fibre based micro contact probe system with high sensitivity and repeatability. In this optical fibre probe with a fused spherical tip, a fibre Bragg grating has been utilized as a strain sensor in the probe stem. When the probe tip contacts the surface of the part, a strain will be induced along the probe stem and will produce a Bragg wavelength shift. The contact signal can be issued once the wavelength shift signal is produced and demodulated. With the fibre grating sensor element integrated into the probe directly, the probe system shows a high sensitivity. In this work, the strain distributions along the probe stem with the probe under axial and lateral load are analysed. A simulation of the strain distribution was performed using the finite element package ANSYS 11. Performance tests using a piezoelectric transducer stage with a displacement resolution of 1.5 nm yielded a measurement resolution of 60 nm under axial loading.

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Internet-based interventions with therapist support have proven effective for treating a range of mental health conditions. This study examined whether frequency of therapist contact affected treatment outcomes. Fifty-seven people with panic disorder (including 32 with agoraphobia) were randomly allocated to an 8-week Internet-based cognitive behavioural treatment intervention (Panic Online) with either frequent (three e-mails per week) or infrequent (one e-mail per week) support from a psychologist. Posttreatment, intention-to-treat analyses revealed that both treatments were effective at improving panic disorder and agoraphobia severity ratings, panicrelated cognitions, negative affect, and psychological and physical quality of life domains, with no differences between conditions. High end-state functioning was achieved by 28.6% of the frequent and infrequent participants, respectively. Therapist alliance, treatment credibility, and satisfaction also did not differ between groups, despite significantly greater therapist time invested in the frequent contact condition. The results provide evidence that the effectiveness of Internet-based mental health interventions may be independent of the frequency of therapist support and may, therefore, be more cost-effective than previously reported.

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The boundary films generated on a series of inorganic compounds, typical of native films on metal and ceramic surfaces, when exposed to various ionic liquids (ILs) based on the trihexyl(tetradecyl)phosphonium cation have been characterized using multinuclear solid-state NMR. The NMR results indicate that SiO2 and Mg(OH)2 interact strongly with the anion and cation of each IL through a mechanism of adsorption of the anion and subsequent close proximity of the cation in a surface double layer (as observed through 1H−29Si cross polarization experiments). In contrast, Al2O3, MgO, ZnO, and ZrO2 appear less active, strongly suggesting the necessity of hydroxylated surface groups in order to enhance the generation of these interfacial films. Using solid-state NMR to characterize such interfaces not only has the potential to elucidate mechanisms of wear resistance and corrosion protection via ILs, but is also likely to allow their rapid screening for such durability applications.

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This paper directly examines the contact sliding distance experienced during a typical sheet metal stamping process-an area that has largely been neglected in the literature. A method to numerically quantify the sliding distance is proposed. The sliding distance predicted from this method, and the contact pressure obtained from numerical simulation, allow the recently identified time-dependent contact conditions on the die and blank surfaces to be completely characterized. Consequently, a new insight into the wear/galling that occurs at the die radius in sheet metal stamping is gained. The results show that the region close to zero degrees on the die radius is likely to experience the most wear, with the identified transient stage contributing to a large proportion of the total wear. Additionally, the region on the blank surface often observed to be heavily burnished - the die impact line - is estimated to experience the highest wear severity due to the transient contact conditions. The proposed method to numerically quantify the sliding contact conditions can be applied as a general approach to study any other two-body sliding contact situations.

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Vocal recognition may function as a critical factor in maintaining the phocid mother-pup bond during lactation. For vocal recognition to function, the caller must produce individually distinct calls that are recognised by their intended recipient. Mother-pup vocal recognition has been studied extensively in colonial otariids and appears to be characteristic of this family. Although less numerous, empirical studies of phocid species have revealed a range of recognition abilities. This study investigated whether Weddell seal (Leptonychotes weddellii) females produce individually distinct 'pup contact' calls that function during natural pair reunions. Fifteen calls from each of nine females recorded in the Vestfold Hills, Antarctica were analysed. One temporal, nine fundamental frequency and five spectral characteristics were measured. Results of the cross-validated Discriminant Function Analysis revealed that mothers produce individually distinct calls with 56% of calls assigned to the correct individual. The probability of achieving this level of discrimination on novel data by chance alone is highly improbable. Analysis of eight mother-pup reunions recorded near McMurdo Sound, Antarctica further demonstrated that these 'pup contact' calls function during natural pair reunions. Behavioural analysis also revealed that pups were chiefly responsible for establishing and maintaining close contact throughout the reunion process. Our study therefore demonstrates that Weddell seal females produce calls with sufficient stereotypy to allow pups to identify them during pair reunions, providing evidence of a functioning mother-pup vocal recognition system.

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Two curved surfaces of molecularly smooth mica are brought into contact under a controlled load, and their deformed shape is measured using optical interference fringes of equal chromatic order. This technique allows exceptionally accurate measurements of surface profiles at separations down to a molecular scale. Contact between the surfaces can be made either adhesive or nonadhesive by suitable choice of the medium between them. Results have been obtained in both cases and compared with the theories of Hertz (nonadhesive contact) and Johnson, Kendall, and Roberts (adhesive contact).