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Goring-Harford, Heather Jane. "Chromium isotope behaviour in natural waters." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/415532/.
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The isotopes of chromium (Cr) fractionate during terrestrial oxidation reactions that require the presence of oxygen. The main source of Cr to the oceans is via rivers, and thus Cr isotopic signatures (expressed as δ53Cr) preserved in authigenic sediments are increasingly being used to reconstruct the oxygen levels of ancient environments. However, Cr can undergo various reactions in natural waters that may fractionate Cr isotopes. The contribution of these reactions to authigenic sediment δ53Cr values is not well understood, and this limits the interpretation of δ53Cr values measured in ancient archives. This thesis describes the development of a method to accurately and precisely measure Cr isotopic signatures in natural waters with extremely low Cr concentrations, and evaluates the behaviour of Cr isotopes in water samples from a range of environmental settings. Seawater samples from the Atlantic Ocean Oxygen Minimum Zone (OMZ) were analysed to evaluate whether Cr isotopic fractionation was enhanced under depleted oxygen conditions. Results indicate that the Atlantic OMZ is not sufficiently depleted in oxygen to reduce and remove Cr from seawater, although δ53Cr values (1.08 – 1.72‰) were variable due to adsorption of Cr(III) to particles on the shelf, and hydrological mixing. Black Sea seawater samples that had dissolved oxygen concentrations close to zero were enriched in 52Cr, resulting in a δ53Cr that was 0.38‰ lower than the overlying fully oxygenated waters. Samples were also taken from the Celtic Sea to investigate the seasonal variation in the Cr isotopic composition of seawater from a biologically productive, oxic shelf sea. Chromium concentrations and δ53Cr values were affected by organic matter cycling, and, as in the Atlantic OMZ region, interactions of Cr with particles on the shelf and hydrological mixing were locally important. Finally, two transects of the Beaulieu River (UK), a relatively pristine river-estuary system, were sampled to assess the behaviour of Cr during estuarine mixing. Both redox species of Cr (Cr(III) and Cr(VI)) and δ53Cr behaved conservatively during mixing between river water and seawater. The Beaulieu River had relatively low δ53Cr (as low as -0.59‰) compared to most other rivers analysed to date, which suggests that the δ53Cr of Cr supplied to the oceans from rivers may be more variable than previously thought.
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Caple, Matt C. J. "Mechanical behaviour of natural turf sports surfaces." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/7389.
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The understanding of the mechanical behaviour of natural turf pitches is limited, owed in part to the deficiencies in current testing devices and methodologies. This research aimed to advance the understanding of surface mechanical behaviour through in-situ and laboratory experiments, and via the development of new testing devices. An impact testing device, the Dynamic Surface Tester (DST) was developed, with impacts replicating the magnitude of stress applied by athletes onto turfed surfaces during running. Developmental experiments indicated that the device was sensitive to changes in soil condition due to variations (P<0.05) in impact data.
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Whttworth, David John. "Monitoring of trace metal behaviour in natural waters." Thesis, University of Plymouth, 1999. http://hdl.handle.net/10026.1/1732.
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An automated voltammetric dissolved trace metal monitor was developed and validated for in situ analysis of estuarine waters. The system was successfully applied to the determination of Ni concentrations during two studies in the Tamar Estuary. The automated system used Adsorptive Cathodic Stripping Voltammetry (AdCSV) for trace metal analysis with a continuous flow sampling procedure and an on line LTV digestion system to ensure complete breakdown of interfering and metal complexing organic ligands. Its application to the measurement of total dissolved Ni in the Tamar Estuary showed a high measuring frequency of up to 6 fully calibrated samples per hour and trace metal concentrations ranged between Ni --10 nM to -50 nM with a salinity gradient of between -0 to -25. A procedure was developed to evaluate suspended particulate material (SPM) trace metal extraction efficiencies of using EDTA extraction solutions followed by analysis of metals using Inductively Coupled Plasma Mass Spectrometry. The use of EDTA allowed the determination of the easily exchangeable particulate metal fraction using well defined constraints with respect to the competition between EDTA and the particles. Optimum particle extraction time was 72 hours, using 0.05 M EDTA concentration and extractant : particle ratio of 200:1, The extraction procedure was applied to the study of particulate Zn, Ni, Cu, Mn and Mg composition of SPM collected from the Scheldt Estuary. In addition, seasonal investigation of dissolved chemical speciation of Cu, Co, Ni and Zn in the Tamar estuary using AdCSV was undertaken. The results showed contrasting behaviour for these metals with a high seasonal variability of Zn and Co and a low seasonal variability for Cu and Ni. The low concentration of Zn and Co during summer months suggested that low river flow rates, low rainfall caused minimal sediment disturbance thereby reducing the contribution of Co and Zn enrich pore waters to the estuary. Furthermore, it was suggested that uptake of Zn and Cu by phytoplankton could have contributed to the lower concentrations of these elements during the summer survey. The electrochemically non labile fraction of dissolved Cu, Zn, Ni and Co exhibited highest values at high salinities and indicates the importance of organic complexation of these metals in the lower estuary. Furthermore, during the spring surveys elevated fractions of organically complexed Cu, Zn, and Ni were observed and it was suggested that seasonally enhanced levels of primary productivity could have lead to the complexation of these elements by algal exudates and break down products. 0.05 M EDTA extraction protocol was applied to the study of dissolved and particulate Zn, Cu, Co and Ni in the Scheldt estuary. Dissolved Co and Ni exhibited elevated concentrations in the upper estuary, which were related to anthropogenic discharges into the estuary. Its was possible to identify a relationship between particulate organic carbon and particulate Zn, Cu and Ni, which suggested that complexation of these elements by organic particulate material was an important factor in their dissolved/particulate partitioning. Results of dissolved Cu natural complexing ligand titration experiments showed similar behaviour for CUL and K^^^ for the Tamar and Scheldt estuaries with high values at low salinity decreasing to low values at high salinity. The Scheldt generally exhibited higher values for K^^,^ and CUL concentrations ( / ^CU^ -15.7; CUL -200 Cu neq 1"*; S = 1) than the Tamar estuary (/C^^^ 14.0; CUL -170 Cu neq 1"'; S = 0). It was suggested that anthropogenic inputs of nutrients in the Scheldt lead to enhanced levels of phytoplankton activity and complexation of Cu by algal exudates and break down products compared with the Tamar. Total dissolved Ni and Co was undertaken on samples collected from the Atlantic Ocean using detection by AdCSV. The results indicated that Ni and Co exhibited contrasting behaviour in the oceanic waters compared with estuarine waters. The distribution of Co showed low concentrations (mean Co -40 pM) in the Atlantic Ocean and elevated concentration associated with aeolian particulate inputs off the Northwest coast of Africa. In contrast, Ni was relatively homogeneously distributed over large parts of the Atlantic (2.4 ± 0.7 nM). However, both Ni and Co exhibited conservative behaviour during mixing between the Brazilian Current with the Ni and Co enriched Falklands Current indicating the importance of physical water transport on trace metal distribution in oceanic systems.
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Armstrong, Christopher Paul. "A characterisation of the exfoliation behaviour of natural graphites." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238713.
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Øiseth, Ole Andre. "Dynamic behaviour of cablesupported bridges subjected to strong natural wind." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for konstruksjonsteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15114.
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This thesis discusses wind-induced dynamic response of slender cable-supported bridges. The focus has been on prediction of the flutter stability limit and the buffeting response in strong winds. The thesis consists of journal papers that are either submitted or published. Multimode flutter has recently been shown to be the governing phenomenon for the aeroelastic stability limit of long-span cable-supported bridges. In this thesis the multimode flutter phenomenon is thoroughly studied. It is concluded that the most important indicator of possible multimode effects is the shape-wise similarity of the vertical and torsional vibration modes since flutter will not occur if the still-air vibration modes are shape-wise dissimilar. When the stability limit of a long-span bridge is assessed, the shape-wise similarity of all possible mode combinations should be evaluated first. Then the system should be grouped into uncoupled subsystems. The subsystem involving the still-air torsional vibration mode with the lowest natural frequency will most likely provide the lowest stability limit. If this subsystem consists of more than two vibration modes, multimode effects will occur. The reduction of the stability limit will be small if the shape-wise similarities of the vibration modes are not of the same order of magnitude, or if the system consists of two torsional and one vertical mode, and the torsional modes are well separated. If these conditions are not fulfilled, the flutter stability limit should be assessed using a multimode approach. The self-excited forces are particularly important when the wind-induced dynamic response or the flutter stability limit is assessed for slender bridges. The self-excited forces can be modelled simply using quasi-steady theory. Since the quasi-steady theory is frequency independent, the model may be used in both the time and frequency domains. However, it is well known that the traditional quasi-steady theory may severely underestimate the flutter stability limit since no aerodynamic torsional damping is introduced into the model. In this thesis a novel modified quasi-steady theory is suggested. The method takes advantage of that the self-excited forces are most important at the natural frequencies of the combined structure and flow system. This implies that curves providing a frequency-independent description of the self-excited forces can be fitted to the experimental data in the important reduced-frequency range corresponding to the natural frequencies of the system. The suggested model has been applied for the Hardanger Bridge in a comprehensive case study, and it is concluded that the model provides wind-induced response and flutter stability limits of good accuracy. Simplified methods for assessment of the flutter stability limit are still considered important in preliminary designs and when designing medium-span bridges where multimode effects will not reduce the flutter stability limit significantly. The most popular approach is still Selberg’s formula, published almost 50 years ago. Selberg’s formula provides the flutter stability limit with reasonable accuracy if the aerodynamic properties of the cross section are similar to those of a flat plate, and the vertical and torsional modes have an identical shape. In this thesis an alternative analytical approach to Selberg’s formula is suggested. The formulae presented are based on the fundamental flutter equations, and the simplified solution is developed by introducing two assumptions. (i) The quasi-steady model for the self-excited forces outlined above is introduced in the equations of motion. (ii) The critical frequency is assumed to be on the torsional branch of the solution system and can be approximated by the uncoupled system of equations. It is demonstrated that by introducing these two approximations, the complexity of the flutter equations is significantly reduced, and if the still-air damping is neglected, a closed-form solution of the flutter stability limit may be obtained. The formula presented is very similar to Selberg’s formula, but contains coefficients taking into account the actual aerodynamic properties of the cross section and the possible imperfect shape-wise similarity of the vibration modes. The formulae presented are tested for a range of hypothetical structural configurations, in addition to the properties of a few well-known bridges, considering the aerodynamic properties of two cross sections. It is concluded that the proposed formulae provide results of adequate accuracy, and that they can be regarded as engineering approximations of the critical flutter velocity. This thesis also discusses unsteady modelling of the self-excited forces in the time domain. A comprehensive case study, where the wind-induced dynamic response of a slender suspension bridge is assessed in the time domain, is presented. Here, the selfexcited forces have been modelled, using rational functions, indicial functions, a novel modified rational function approach explained and introduced in this thesis, and a further developed modified quasi-steady theory. The quasi-steady model is a further development of the model outlined above. As explained above, in the modified quasisteady theory suggested in this thesis, the experimental results of the aerodynamic derivatives are approximated with curves providing a frequency-independent description of the self-excited forces in the important reduced-frequency range. This implies that the self-excited forces may be accurately modelled at frequencies corresponding to one horizontal, one vertical, and one torsional vibration mode. The further development presented here is to uncouple the aeroelastic system utilizing the right- and left-hand eigenvectors. This implies that the experimental results for the aerodynamic derivatives may be accurately approximated for all the natural frequencies of the aeroelastic system. It is concluded that all the unsteady models evaluated provide an adequate description of the self-excited forces, but that the unsteady models may be challenging to fit to the experimental data since the same coefficients are used in the expressions for the imaginary and real part of the transfer functions, which implies that two sets of data have to be approximated using the same coefficients. It is also seen that the quasi-steady model presented provides satisfying results. The results are in fact of higher accuracy than when some of the unsteady models are applied. As modern bridges become longer, slenderer and lighter, the use of nonlinear methods to evaluate the dynamic response may become necessary. This implies that time domain assessment of the wind-induced dynamic response will become more important in the future. When nonlinearities are introduced into the model, it is an advantage to use the degrees of freedom of the element model directly and not use still-air vibration modes as generalized degrees of freedom. This can be done modelling the self-excited forces at distinct points along the girder, but this will imply that a huge amount of convolution integrals have to be evaluated at each time step. Another approach is suggested in this thesis. The starting point is a traditional beam element with twelve degrees of freedom, where the convolution integrals are added as aerodynamic degrees of freedom in each node. This implies that the convolution integrals do not need to be evaluated explicitly, since their value is calculated just like the response of the structure. Four different aeroelastic beam elements have been developed and tested. It is concluded that the elements provide wind-induced dynamic response and flutter stability limits that correspond very well to results predicted by the traditional multimode approach in the frequency domain. Accurate modelling of the wind field is a crucial issue when predicting the dynamic response of long-span bridges. The wind field is most commonly modelled as a multivariate Gaussian stationary and homogeneous stochastic process, where the turbulence components are assumed independent. Since the wind field is affected by the roughness at the site, the turbulence components will become correlated, since threedimensional eddies are generated by the roughness elements, but this effect is normally neglected. In this thesis the measurements of the fluctuating wind carried out at the Sotra Bride in 1975 are reinvestigated. The cross-spectral densities of all the turbulence components have been determined using auto regressive (AR) models. It is concluded that the cross-spectral density of the u and w components may have a significant influence on the dynamic response, in particular for structures with low natural frequencies. However for the bridge considered, reasonable estimates of the windinduced dynamic response will still be obtained if the cross-spectral density of the u and w components is neglected, but the accuracy of the modelling will be improved if it is included.
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Bentley, Katie Anne. "Adaptive behaviour through morphological plasticity in natural and artificial systems." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1444539/.
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Our concept of intelligence is changing. Embodiment has led to the rise of morphologies in Artificial Intelligence (AI) research. This thesis focuses on two research questions: 1) How can system morphologies, well-adapted to changing environments, be designed? 2) How can adaptive behaviour be generated through morphology? It is the fundamental argument of this thesis that morphological plasticity (MP), the environmentally induced variation in growth or development, can provide a solution to both questions. Specifically, this thesis is based around a detailed study of diatom valve morphogenesis. Diatoms, a unicellular organism, construct intricate siliceous structures (valves) around themselves which exhibit high plasticity to the environment. Diatom valve morphogenesis is a good example of how morphologies can be well-adapted to changing environments, an open problem in AI, and how adaptive behaviour can be generated through morphological processes alone. Through a constructivist approach this thesis contributes to both understanding of MP in natural systems and the design of MP algorithms for artificial adaptive systems. Several original models and frameworks are defined within this thesis: the Nature's Batik Model of basic diatom valve morphogenesis the Cellanimat, a 'Dynamic Morphology' based on the unicell, capable of MP driven adaptive behaviour through its unique 'Artificial Cytoskeleton' model of cytoskeletal dynamics the Environment-Phenotype Map framework and the Cellanimat Colony Model, which combines all previous models for the investigation of MP mechanisms during diatom colony formation. Cellanimat dynamics and optimization are thoroughly investigated and the model is shown to be multi functional, evolvable, scalable and reasonably robust.
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Polatoğlu, İlker Özkan Fehime. "Chemical behaviour of clinoptilolite rich natural zeolite in Aqueous medium /." [S.l. : s.n.], 2005. http://library.iyte.edu.tr/tezler/master/kimyamuh/T000352.pdf.
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Thesis (Master)--İzmir Institute Of Technology, İzmir, 2005.Keywords: Natural zeolite, clinoptilolite, aqueous media, ion exchange, adsorption. Includes bibliographical references (leaves . 70-73).
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Attewell, David. "The Natural Reflectance Signal and its Implications for Vision and Behaviour." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520588.
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Miflah, Hussain Ismail Ahamed. "Higher-level representations of natural images." Thesis, Queen Mary, University of London, 2018. http://qmro.qmul.ac.uk/xmlui/handle/123456789/39759.
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The traditional view of vision is that neurons in early cortical areas process information about simple features (e.g. orientation and spatial frequency) in small, spatially localised regions of visual space (the neuron's receptive field). This piecemeal information is then fed-forward into later stages of the visual system where it gets combined to form coherent and meaningful global (higher-level) representations. The overall aim of this thesis is to examine and quantify this higher level processing; how we encode global features in natural images and to understand the extent to which our perception of these global representations is determined by the local features within images. Using the tilt after-effect as a tool, the first chapter examined the processing of a low level, local feature and found that the orientation of a sinusoidal grating could be encoded in both a retinally and spatially non-specific manner. Chapter 2 then examined these tilt aftereffects to the global orientation of the image (i.e., uprightness). We found that image uprightness was also encoded in a retinally / spatially non-specific manner, but that this global property could be processed largely independently of its local orientation content. Chapter 3 investigated if our increased sensitivity to cardinal (vertical and horizontal) structures compared to inter-cardinal (45° and 135° clockwise of vertical) structures, influenced classification of unambiguous natural images. Participants required relatively less contrast to classify images when they retained near-cardinal as compared to near-inter-cardinal structures. Finally, in chapter 4, we examined category classification when images were ambiguous. Observers were biased to classify ambiguous images, created by combining structures from two distinct image categories, as carpentered (e.g., a house). This could not be explained by differences in sensitivity to local structures and is most likely the result of our long-term exposure to city views. Overall, these results show that higher-level representations are not fully dependent on the lower level features within an image. Furthermore, our knowledge about the environment influences the extent to which we use local features to rapidly identify an image.
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Stamataki, Sofia. "Application of equations of state to gas condensate phase behaviour modelling." Thesis, Heriot-Watt University, 1986. http://hdl.handle.net/10399/2126.
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Gurden, Ross Brian. "Bioinformatics approaches to studying mesenchymal stem cell behaviour on artificial extracellular matrices." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/9039/.
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Stem cells have potential use in tissue engineering and regenerative medicine, and as they underlie the development and maintenance of tissues throughout life, how they function is also of interest. The extracellular matrix presents a variety of physical and chemical signals to stem cells to regulate their behaviour in vivo. Recapitulation of these signals in vitro could enable the control of explanted stem cells to facilitate their study. Biomaterials that display extracellular-matrix inspired cues are one way to do this. By combining surface chemistry and fibronectin, an extracellular matrix protein with cell binding and growth factor binding domains, the conformation of fibronectin was controlled to create artificial extracellular matrices. Adsorbed on a film of poly(ethyl acrylate), fibronectin adopted a network-like conformation which ostensibly increased the exposure of its functional domains, whereas on poly(methyl acrylate) it had an unconnected organisation with more concealed domains. The growth factors bone morphogenetic protein 2 and vascular endothelial growth factor, known to bind to fibronectin, were adsorbed to the network conformation. Prior studies have reported that these artificial extracellular matrices differentially affected cell behaviour. In this work, the growth and differentiation of human bone marrow stromal cell surface marker-1 positive mesenchymal stem cells was characterised on these substrates. It was shown that all combinations of fibronectin conformation and growth factors supported cell adhesion and growth. A high-content image processing and analysis pipeline was developed to take advantage of automated fluorescence microscopy to show that cytoskeletal, nuclei, and differentiation-associated protein features distinguished cells cultured on the artificial extracellular matrices. Those on the isolated conformation and the network conformation with vascular endothelial growth factor were particularly distinct. Further, metabolomics revealed several metabolic pathways that differed in activity between the fibronectin conformations. To analyse the metabolomics data a Quick Results web application was built, which extended the existing Polyomics integrated Metabolomics Pipeline. The application improves the visualisation and interpretation of untargeted liquid chromatography—mass spectrometry metabolomics data. This work gives insights into how these artificial extracellular matrices can control stem cell behaviour, and developed and demonstrated several tools to improve the understanding of these biomaterials and the use of metabolomics data.
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Vithana, Sarath Opatha. "Performance assessment methods for the behaviour of natural and artificial harbour inlets." Title page, contents and synopsis only, 1991. http://web4.library.adelaide.edu.au/theses/09ENS/09ensv844.pdf.
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Pearce, Rebecca. "Blind belief in a commodified natural resource : a grounded theory." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/15037.
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This research examines the application of a Classic Glaserian Grounded Theory methodology to the phenomenon of drought when viewed from the perspective of household water users in southern England. The resulting conceptual work calls into question the effectiveness of water-wise messaging and current Government policies on water management, by highlighting the double assurances afforded to the public through their own observations of the natural cycling of water resources between atmosphere and land, and the continuous operation of the regulated water industry, that together sustain blind belief in the ongoing availability of potable water resources. To establish a clear separation between the development of substantive theory and mixed method studies that claim to take a grounded theory approach that are generally more popular within the discipline of Human Geography, the theory is presented alongside two pieces of work; a collection of modern drought histories and a questionnaire. Developed as part of the necessary process of cycling alternate projects to enable a theory to emerge from the data whilst the researcher is distracted from forcing her own ideas onto it, both these pieces can be viewed separately or as supportive companions to the theory. Additionally, in acknowledging the difficulty in presenting a Classic Grounded Theory in the traditional discussional form, for the benefit of the reader the theory is preceded by an autoethnography, which incorporates descriptive elements taken from field notes and the author’s personal water diary. These works draw data from subjects in three counties in England (Norfolk, Kent, and Devon), following the northwest – southeast rainfall gradient. Supplementary material for the drought histories is drawn from local and national archives and recorded oral histories. The primary emphasis of this work is placed on assessing the merits of each of the methods deployed in addressing environmental social science issues in the context of climate change, which hitherto have been focused on perception questionnaires and the development of popular cultural typologies.
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Davis, Simon. "Optimal foraging behaviour of nectar gathering bumblebees : a doubly labelled water study." Thesis, Liverpool John Moores University, 1995. http://researchonline.ljmu.ac.uk/5099/.
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Andersson, Annelie. "Maternal behaviour, infanticide and welfare in enclosed European wild boars (Sus scrofa)." Licentiate thesis, Linköpings universitet, Zoologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57985.
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European wild boars (Sus scrofa) are kept in Swedish enclosures for hunting and meat production purposes. The sows are known to undergo behavioural changes in connection with farrowing and their natural behaviours may be compromised by the limited area of the enclosure. The general aim of this thesis was to provide detailed quantitative data on wild boar sows when farrowing in captivity and to report whether possible needs can be compromised by the limitations of an enclosure. Specifically, it was aimed to provide a quantitative and functional account of the occurrence of infanticide, and its possible relations to welfare of confined wild boars. A field study was carried out in a hunting enclosure, where 1200 hours of behavioural recordings and data from 22 farrowings were collected. The farrowing period could be divided into three phases: pre-farrowing, isolation and sociality phases (in relation to farrowing: day -14 to -1, day 1 to 8, day 9 to 14 respectively). The activity decreased during isolation and increased in the sociality phase. The average distance to other individuals increased during isolation and decreased in the sociality phase. Habitat use changed towards more protective habitats after farrowing (Paper I). Non-maternal infanticide was documented in 14 out of 22 litters. Infanticide, typically performed by an older and larger sow than the mother, caused the deaths of all neonates in all but one affected litters. We found no effect of relatedness. A questionnaire sent to 112 owners of enclosures in Sweden and Finland resulted in 62 responses. Although the owners were often not able to provide exact figures on reproduction and mortality, nonmaternal infanticide was reported to be the most common cause of piglet mortality. The occurrence of infanticide was unrelated to size of enclosure and to variations in husbandry routines. All together results may suggest that non-maternal infanticide is part of the normal behavioural repertoire in wild boars (Paper II). The studies of this thesis reveals the farrowing period as the most dynamic and perhaps most challenging for wild boar sows in enclosures. There are serious welfare concerns in the husbandry of wild boars in Swedish enclosures. The most obvious welfare problem is non-maternal infanticide, where both sows and piglets are assumed to suffer, and where the outcome from the action must be considered unacceptable. If wild boar husbandry shall be equated with other animal husbandry in our society, it needs to be regulated to overcome many of the presented potential welfare problems in this thesis.Europeiskt vildsvin (Sus scrofa) hålls i svenska hägn för jakt och köttproduktion. I samband med grisning genomgår suggan beteendeförändringar och där kan suggans naturliga beteenden tänkas hindras av de begränsningar som hägnet utgör. Det övergripande syftet med den här avhandlingen var att redovisa detaljerade kvantitativa uppgifter om vildsvinsuggors grisning i ett jakthägn, samt att rapportera om möjliga behov hos suggan äventyras på grund av begränsningarna av ett hägn. Särskilt syftar avhandlingen till att ge en kvantitativ och funktionell beskrivning av förekomsten av infanticid (kultingdödlighet orsakad av artfrände) och dess eventuella påverkan på hägnade vildsvins välfärd. En fältstudie genomfördes i ett jakthägn, där 1200 timmar beteendeobservationer och data från 22 grisningar samlades in. Grisningsperioden kunde delas in i tre faser: grisnings-, isolerings- och sociala fasen (i relation till grisningsdagen: dag -14 till -1, dag 1 till 8, respektive dag 9 till 14). Aktiviteten minskade under isoleringsfasen och ökade i sociala fasen. Det genomsnittliga avståndet till andra individer ökade under isoleringsfasen och minskade i sociala fasen. Habitatutnyttjandet förändrades mot mer skyddande habitat efter grisningen (Paper I). I 14 av 22 kullar observerades icke-maternell infanticid. Infanticiden utfördes vanligtvis av en äldre och större sugga än modern, och var orsaken till att alla kultingar dog i alla utom en av berörda kullar. Det fanns ingen släktskapseffekt på infanticiden. En enkät som skickades till 112 hägnägare i Sverige och Finland resulterade i 62 svar. Trots att ägarna ofta inte kunde ge exakta siffror på reproduktion och dödlighet så rapporterades icke-maternell infanticid som den vanligaste orsaken till kultingdödlighet. Förekomsten av infanticid saknade samband med storlek på hägn och variationer i rutiner för djurhållningen. Resultaten tyder på att icke-maternell infanticid är en del av den normala beteenderepertoaren hos vildsvin (Paper II). Studierna i denna avhandling visar att grisningsperioden kan vara den mest dynamiska och kanske svåraste för vildsvinsuggor i hägn. Det finns allvarliga djurskyddsproblem i djurhållningen av vildsvin i svenska hägn. Det mest uppenbara välfärdsproblemet är icke-maternell infanticid, där både suggor och kultingar antas lida, och där resultatet av beteendet måste anses oacceptabelt. Om vildsvinshållning skall likställas med annan djurhållning i vårt samhälle, behöver den regleras för att övervinna många av de potentiella djurskyddsproblem som påvisas i denna avhandling.
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Champagne, Frances Anne. "Natural variations in maternal behaviour in the rat : neural mechanisms and environmental regulation." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85057.
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Oxytocin-estrogen interactions are critical to the neuroendocrine and behavioural changes that occur in the maternal rat. The question that remains is whether these interactions mediate the expression of individual differences in maternal care and the generational transmission of this behaviour. Maternal licking/grooming (LG) is a normally distributed, stable behaviour in the lactating rat that is transmitted to female offspring. Levels of oxytocin receptor (OTR) binding in the medial preoptic area (MPOA), a region critical for maternal behaviour, are elevated in females exhibiting high vs . low levels of LG. Central administration of a selective OTR antagonist reduces LG behaviour in High LG females to levels comparable to those observed in Low LG females, supporting the functional role of these receptors in LG. The female offspring of High and Low LG mothers differ in estrogen sensitivity in the MPOA. Ovariectomized, estrogen-treated female offspring of High LG mothers exhibit increased OTR binding and Fos immunoreactivity whereas the offspring of Low LG mothers show no estrogen-mediated increases. Estrogen up-regulation of OTR levels is known to involve estrogen receptor alpha. Levels of estrogen receptor alpha in the MPOA are elevated in High LG compared to Low LG mothers and their female offspring. Mesolimbic dopamine activity is a potential downstream target of estrogen-oxytocin interactions, and we have shown that nucleus accumbens dopamine activity and levels of D1 and D3 dopamine receptors are associated with high levels of LG behaviour.Adoption studies suggest that the expression of LG behaviour is environmentally mediated. We have shown that gestational stress can reduce licking/grooming behaviour of High LG mothers and that this reduction is correlated to a stress-induced decrease in OTR binding in the MPOA. These behavioural and neuroendocrine changes are long-term and are passed on to the female offspring of these mothers. Post-weaning isolation also reduces maternal licking/grooming behaviour and OTR binding in the offspring of High LG mothers. Conversely, post-weaning social enrichment enhances LG behaviour and OTR binding in the female offspring of Low LG mothers.
Overall, these studies describe an environmentally regulated estrogen-oxytocin mechanism that mediates the expression of natural variations in maternal care in the rat.
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Doering, Che. "Measurements of the distribution and behaviour of Beryllium-7 in the natural environment." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16513/.
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Beryllium-7 is a cosmogenic radionuclide produced in the atmosphere through the spallation of nitrogen and oxygen nuclei by cosmic-ray-produced neutrons and protons. It is carried in the atmosphere attached to aerosols and is deposited on land and ocean surfaces by wet and dry deposition processes. Beryllium-7 decays by electron capture to lithium-7 and has a half-life of approximately 53 days. It is a potentially useful radionuclide for studying different natural processes. This thesis presents a collection of scientific papers on the occurrence of beryllium-7 in the natural environment, particularly in the Southeast Queensland region of Australia. It shows the results of experimental measurements and discusses their implications. Overall, this thesis contributes to advancing our understanding of the distribution and behaviour of beryllium-7 in the natural environment and provides a foundation for the development of nuclear techniques for the evaluation of environmental problems.
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Copello, Alexandre Georges. "Responding to addiction in the family : natural and assisted change in coping behaviour." Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288573.
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Jackson, Lawrence. "Mother offspring behaviour in mice : the influence of natural and adjusted litter size." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317471.
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Scrafton, Sharon. "Familiarity in natural behaviour : effect of task, objects and environment on gaze allocation." Thesis, University of Dundee, 2015. https://discovery.dundee.ac.uk/en/studentTheses/1d26b52f-81df-49c4-b832-0a0dba489ffb.
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For active tasks we have to appropriately allocate our gaze spatially and temporally so that we are fixating informative areas when the crucial information is available. We know that vision supports action, and several fundamental elements of how this is so have been established, for example that the eye leads the hand during action. What we do not know is whether the spatiotemporal allocation of gaze is consistent regardless of the task, the objects and the level of familiarity we have with the environment. In Chapter 3 we found that visual behaviour changes as a result of the task being undertaken, with more looks to task irrelevant objects, longer eye-hand latencies and more visually guided putdowns of objects made for tea making rather than sandwich making. Analysis revealed that the objects used in the two different tasks did affect eye-hand latencies. In Chapter 4 this issue was explored further and it was found that the properties of objects (glasses) such as glass type (where height may be the important factor) influenced visual guidance if the glass was empty during the set down, but that level of liquid contained, and the material it was made from impacted the likelihood of using visual guidance for a second putdown of the same glass. These results indicate flexibility in terms of the allocation of visual guidance depending on our knowledge of the object properties, and suggest that risk may be an important factor in this. The effect of familiarity with an environment was looked at in three ways. First in Chapter 5 we compared people making tea in familiar environments (their own kitchens) and in novel environments (their experimental partners kitchen). Second we explored the acquisition of familiarity by having participants perform a task in the same environment for 10 consecutive days (Chapter 6) and finally we investigated what information was encoded incidentally by having the participants from Chapter 6 perform a new task in the same environment for two subsequent days. We found that people were faster to complete the same task in a familiar environment than a novel one but that it was not just that search was facilitated and thus shorter, visual behaviours such as visual exploration and looks to task irrelevant objects were fewer when in familiar environments and several elements of the Object Related Action (ORA) also reduced in a temporal nature. We found that during the acquisition of familiarity people encoded information about the layout of objects in the scene which facilitated search in Chapter 7 but there appeared to be no such effect on the ORA, suggesting that object specific information for task irrelevant objects is not incidentally encoded. The findings of this thesis suggest that spatiotemporal allocation of gaze in natural tasks depends on the context of the environment, the properties of objects and our level of prior knowledge.
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Mavraki, Aikaterini. "The effects of environment and microstructure on the mechanical behaviour of natural fibres." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/8340.
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Cawley, James. "Natural repertoires of functional communication in children with learning disabilities and challenging behaviour." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397205.
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GarciÌa-Ortega, Susana. "The environmental behaviour and toxicological effect of propetamphos in an estuarine environment." Thesis, Bangor University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273671.
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Green, Jonathan Andrew. "The behaviour and energetics of macaroni penguins (Eudyptes chrysolophus)." Thesis, University of Birmingham, 2001. http://etheses.bham.ac.uk//id/eprint/4758/.
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Heart rate (f\(_H\)) and rate of oxygen ( V\(_{O2}\) consumption were recorded from adult macaroni penguins while exercising on a treadmill. No differences were found in the relationship between f\(_H\) and V\(_{O2}\) in breeding and moulting female penguins, but a significant difference was found between male and female penguins. These relationships were used to estimate field metabolic rate (FMR) for free-ranging female penguins, which were implanted with heart rate and temperature data loggers. While foraging to provision their chick, FMR was 8.92 ± 0.44 W kg\(^{-1}\) and 9.07 ± 0.42 W kg\(^{-1}\) respectively while at-sea during the brood and crèche phases of the breeding season. While on-shore, the FMR was 6.08 ± 0.43 W kg\(^{-1}\) and 5.64 ± 0.40 W kg\(^{-1}\) respectively for the brood and crèche phases. During their moult fast, male and female penguins showed a pattern of increasing and then decreasing FMR and females had a mean FMR of 5.25 ± 0.88 W kg\(^{-1}\). The peak of energy expenditure was associated with maximum feather loss, probably due to increased costs of thermoregulation. During natural diving, penguins showed complex fluctuations in heart rate. Abdominal temperature fell during dive bouts with the magnitude of this decline increasing with bout length. Put together, these adjustments in heart rate and circulation may be enough to enable all natural dives to be aerobic in nature.
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Tracey, Justine. "Cultural behaviour or natural processes? A review of southern Britain iron age skeletal remains." Thesis, University of Reading, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558773.
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This thesis focuses on the British Iron Age and challenging the current hypotheses of exposing the dead on five Iron Age sites in Hampshire and one from Dorset, England. Current theories are based on anthropological analogies and classical texts to understand and interpret the burial record. However, this research focused on understanding the formation of the burial record employing a new science-based methodology. This new approach is both integrated and multidisciplinary, combining the osteological and context taphonomic physical or material evidence to discern cultural behaviour from natural processes. The approach utilises a wide range of forensic anthropology and taphonomy, including I 'anthropologie de terrain or archaeothanatology, to identify archaeological signatures from three key and interrelated areas: the remains, the deposition context, and the relationship between the corpse and its deposition circumstance. A new system of categorising Iron Age remains was developed to differentiate funerary and depositional behaviour between sites. The results show that during the Iron Age , several depositional practices can be observed: intentional exposure, propitiatory deposits and intentional practices where the body was kept whole in death which ran in parallel with each another. The research also identified the need to integrate burial data from the outset, including associated finds and stratigraphic evidence in order provide a comprehensive account of funerary and depositional practices.
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Laudone, Giuliano Maurizio. "Environmentally friendly technology : the behaviour of natural and synthetic binder systems within paper coatings." Thesis, University of Plymouth, 2005. http://hdl.handle.net/10026.1/2377.
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Coating shrinkage upon drying is a phenomenon well known to the paper coating industry, where it often causes changes in the final structure of the coating layer leading to poor results in terms of gloss, light scattering, surface strength, coverage, uniformity and printability. Such shrinkage has in previous studies been wrongly associated with shrinkage of the polymeric binders used in the coating formulation, by making erroneous comparison with solvent-based paint systems. Natural binders, as starch or proteins, which come from renewable resources and are therefore environmentally friendly, suffer more from this shrinkage phenomenon than synthetic binders. The aim of this research project was to improve the understanding of the processes involved in the drying of a coating layer and to create a model able to describe them. Shrinkage while the coating layer dries has been successfully measured by observing the deflection of coated strips of a synthetic elastically-deformable substrate. Ground calcium carbonate was used as the coating pigment, together with latex binders of both low and high glass transition temperature, Tg, respectively, and also with starch which is a natural film-forming water soluble binder. The final dry coatings were studied with mercury porosimetry and by scanning electron microscopy in order to characterise their porous structure. The flow and rheological properties of the coating colour formulations were measured in order to probe the particle-particle interaction between the different species in the wet coating colour. The void space of the dry coating layers was modelled using Pore-Cor, a software which generates simulated porous networks. A new algorithm was developed to model, within the simulated void space, the effective particles or "skeletal elements" representative of the solid phase of the dried porous system. The water-filled porous structures at the beginning of the shrinkage process (first critical concentration, FCC) were subsequently modelled by creating Pore-Cor structures with the same solid skeletal elements distribution as at the second critical concentration (at which the particles lock their positions), but with higher given porosity to account for the water present The capillary forces acting on the surface of the simulated coating were calculated, and found to be several orders of magnitude larger than the measured shrinkage forces. The shrinkage process was thus described as resulting from the effect of capillary forces in the plane of the coating layer resisted by a stick-slip process, where the capillary forces yield shrinkage only if a resistance force within the drying coating layer holds the structure in place and allows the menisci to form. The stick-slip theory was strongly supported by quantitative comparisons between the experimental forces required to intrude mercury, and the capillary forces within the simulated void structure.
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Newton, P. P. "The role of organic matter in the behaviour of suspended particles in natural water." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381750.
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Nätt, Daniel. "Heritable epigenetic responses to environmental challenges : Effects on behaviour, gene expression and DNA-methylation in the chicken." Doctoral thesis, Linköpings universitet, Zoologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70155.
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Phenotypic variation within populations is a crucial factor in evolution and is mainly thought to be driven by heritable changes in the base sequence of DNA. Among our domesticated species we find some of the most variable species on earth today. This variety of breeds has appeared during a relatively short evolutionary time, and so far genetic studies have been unable to explain but a small portion of this variation, which indicates more novel mechanisms of inheritance and phenotypic plasticity. The aim of this study was therefore to investigate some of these alternative routes in the chicken, especially focusing on transgenerational effects of environmental challenges on behaviour and gene expression in relation to domestication. In two experiments a chronically unpredictable environment induced phenotypic changes in the parents that were mirrored in the unexposed offspring raised without parental contact. This transmission was especially clear in domesticated birds. A third experiment showed that repeated stress events very early in life could change the developmental program making the birds more resistant to stress later in life. Here, the phenotypic changes were also mirrored in the unexposed offspring and associated with inheritance of gene expression. Epigenetic factors, such as DNA-methylation, could play an important role in the mechanism of these transgenerational effects. A fourth experiment showed that wild types and domesticated chickens differed substantially in their patterns of DNA-methylation, where the domesticated breed had increased amount of promoter DNA-methylation. In line with the previous experiments, this breed also showed increased transmission of methylation marks to their offspring. Conclusively, parental exposure of environmental challenges that introduce changes in behaviour, physiology and gene expression can under both chronic and temporal conditions be heritably programmed in the parent and transmitted to the unexposed offspring. Since heritable epigenetic variation between wild type and domesticated chickens is stable and numerous, it is possible that selection for favourable epigenomes could add another level to the evolutionary processes and therefore might explain some of the rapid changes in the history of the domesticated chicken.
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Rusli, Rafeadah. "Interfacial micromechanics of natural cellulose whisker polymer nanocomposites using Raman spectroscopy." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/interfacial-micromechanics-of-natural-cellulose-whisker-polymer-nanocomposites-using-raman-spectroscopy(2eab8693-78b1-4241-bcfb-f7d2ae39fbf6).html.
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Raman spectroscopy has been used to monitor the deformation of natural cellulose whisker polymer nanocomposites. Cotton and tunicate whiskers were used as reinforcements in polymer matrices. Raman spectra from the nanocomposites highlight an intense band located at the 1095 cm-1 position. This band is reported to shift towards a lower wavenumber under the application of tensile deformation. On the other hand, the compressive deformation of the composite gives rise to an increase in the position of this Raman band. The shifts correspond to the direct deformation of the molecular backbone of cellulose, which is dominated by a C-O stretching mode. The Raman band located at 1095 cm-1 is shown to shift non-linearly before it reaches a plateau due to the breakdown of the whisker-matrix interface. The initial shift rate is associated with the stiffness of the cellulose whiskers. The stiffnesses of single whiskers of cotton and tunicate are found to be 58 and 155 GPa respectively, assuming two dimensional (2D) in-plane distribution of whiskers. Cyclic deformation tests of the composites provide an insight into understanding the behaviour of the whisker-polymer matrix interface under tension and compression. It is found that residual compressive stress occurs during each cycle of the deformation. The level of disruption at the whisker-matrix interface is determined by estimating the energy dissipation, which is proportional to the hysteresis area. Local orientation is also observed in the nanocomposites produced by solution casting and subsequent melt pressing. Dark regions of the composites viewed under a polarised optical microscopy are found to represent areas in which the cellulose whiskers form a randomly oriented whisker network. A shift rate for the Raman band initially located at 1095 cm-1 obtained in the dark regions of 12.2 vol% tunicate whisker poly(vinyl acetate) nanocomposites is found to be -0.5±0.07 cm-1%-1, which is lower than -1.2±0.04 cm-1%-1 from the bright regions. Exposure to water and temperature during the deformation of the nanocomposites results in significant changes in stress transfer between the whiskers and the matrix. It is shown that the interface can be 'switched-off' for the poly(vinyl acetate)/whisker system in the presence of water and also at temperature above the glass transition.
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Xu, Xiaolu. "Uranium associations and migration behaviour at the Needle's Eye natural analogue site in SW Scotland." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/10445.
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This thesis investigated uranium (U) migration behaviour at the Needle‟s Eye natural analogue site, located close to Southwick Water, South West Scotland. The results of this study are important for the prediction of U behaviour in the far-field environments of nuclear waste repositories over long time-scales. The Needle‟s Eye natural analogue site was selected because the processes involved in U mobilisation, the direction of water flow and the extent of retention of uranium in peaty soils had already been identified. To this end, previous results demonstrated that groundwater passing through the mineralisation oxidized U and transported it to the peaty area, where 80-90% of the released U has been retained. Sequential extraction of the peaty soils indicated that more than 90% of the solid phase U was bound to the organic fraction. However, in-depth characterisation of U associations within the soil porewaters and the peaty soils at this site was lacking. Therefore, the processes controlling the migration of uranium within this organic-rich system were the main focus of this study. There were five sampling trips carried out from 2007-2011, in which cave drip waters, bog waters and surface soil and soil core samples were selectively collected for analysis by a range of methods described below. The cave drip waters emerging from the mineralisation were oxidizing and slightly alkaline (7.6-7.8), U was mainly in truly dissolved (<3 kDa) forms (Ca2UO2(CO3)30, CaUO2(CO3)32- and UO2(CO3)22-). It is known that the formation of the ternary Ca-UVI-CO3 complexes inhibits the reduction of U and so it is likely that it is UVI that is present within the peaty soils and their associated porewaters. Sampling trip 1 quantified the U concentrations in cave waters and soil core porewaters. By 30 m from the cave, U concentrations in the soil porewaters had decreased by a factor of ~10. Ultrafiltration fractionated the colloidal fraction (3 kDa-0.2 μm) into large (100 kDa-0.2 μm), medium (30-100 kDa) and small (3-30 kDa) colloidal fractions. It was found that U was mainly associated with the large colloid (100 kDa-0.2 μm) but, with increasing distance from the mineralisation, the U distribution became bimodal with both large and small fractions being equally important. Iron (Fe) was exclusively associated with the large colloid fraction in the peaty soil porewaters. Gel electrophoresis and gel filtration, applied to study the interactions of U (and other elements) with humic substances (HS), showed that the associations were quite uniform with increasing depth of the cores and increasing distance from the U mineralisation. Uranium (and other elements including Fe) was associated with the largest humic molecules. Sampling trip 2 involved collection of three more soil cores and ultrafiltration again fractionated the total dissolved porewater into large, medium and small colloids. This time, the truly dissolved (<3 kDa) fraction was also analysed. Again, U was mainly associated with the large colloidal (100 kda-0.2 μm) fraction. With increasing distance and increasing depth, U was still predominantly associated with the large colloidal fraction, but the importance of the truly dissolved (<3 kDa) phase could not be neglected. At the same time, Fe was also mainly associated with the large colloidal fraction. The remainder of the experimental work on samples from trip 2 focused on determining the importance of U associations with both Fe and humic components of the solid phase. Sequential extraction of the whole soil mainly targeted different iron phases and found that U was mainly released in the sodium acetate and sodium dithionite solutions, which indicated U was associated with (i) Fe carbonates; and (ii) crystalline Fe oxides (e.g. goethite, hematite, and akaganetite). However, very little Fe was extracted in the “carbonate-bound” fraction and separate experiments showed that U was not associated with Fe carbonates but instead had been released from the surfaces of HS and humic-bound Fe surfaces. XRD spectroscopy showed that mineral compositions were in reasonable agreement with the sequential extraction results and SEM-EDX analysis indicated that U in the soil was generally not present in crystalline form, as only two particles with high U content were found after 4-hour searching. Exhaustive extraction of HS showed that >90% U was associated with organic substances, in agreement with previous work and novel experiments involving gel electrophoresis in conjunction with sequential extraction was used to study the relationships between U, Fe and the HS. It was demonstrated that ~20-25% U was weakly held by the HS or at humic-bound Fe surfaces, ~45% was incorporated into crystalline Fe oxides which were intimately associated with HS and the remainder was in the form of strong U-CO3-humic complexes. In sampling trip 3, U migration behaviour in the soil porewaters was the focus. A 30-m transect line, comprising seven0-5 cm soil samples, starting at the cave and passing through the peaty area towards the Southwick Water, was established. Soil porewaters from these surface soils were fractionated into colloidal (3 kDa-0.2 μm) fraction and truly dissolved (<3 kDa) phase. There was a major change in U speciation, from Ca2UO2(CO3)3 0,CaUO2(CO3)32- and UO2(CO3)22- in the truly dissolved fractions of waters close to the cave to a predominant association with the highly coloured colloidal fractions as soon as the boggy area was reached. With distance through the boggy area, it was clear that the colloidal U was being incorporated into the solid phase since porewater concentrations had decreased ~100-fold by 30 m from the cave. Ultrafiltration in conjunction with acetate extraction was then used to extract U from the porewater colloids isolated from a soil core (20 m from cave). In the organic-rich portion of the core (0-30 cm), ~60-70% U was colloidally associated and ~85-95% of this U was extracted from the colloidal fraction. This indicated that the interactions between U and the porewater colloids were weak. In sampling trip 4, U associations in the porewater colloids were still the main focus. Gel filtration of porewater colloids confirmed that U, Fe and humic colloids were intimately associated. It was concluded that although U in the cave drip water was mainly in truly dissolved forms, weak U----humic/Fe colloids were formed immediately when U entered the peaty area. In sampling trip 5, results for soil core porewaters showed that Fe in the whole core was mainly in the form of FeII. Thus strongly reducing conditions prevailed through the core which was situated within the peaty area. Combining the results from the five sampling trips, three zones within the peaty area were distinguished. Zone I was characterised by extremely high concentrations of dissolved HS and this was where the change in U speciation from dissolved to colloidal forms took place. Zone II contained most of the soil cores collected during this study and was characterised by strongly reducing conditions and moderate concentrations of HS. Colloidal U was removed to the solid phase as waters flow through this area. Zone III marks the transition to the saltmarsh. Focusing on Zone II, a conceptual model of U behaviour was developed: upon entering the peaty area, U is weakly held by very large humic-Fe colloids. These colloids are removed to the solid phase and over time the associations of U are transformed; some becomes incorporated into stable humic-bound crystalline oxides as a result of redox cycling of Fe, some becomes strongly complexed to HS and the remainder is weakly held by the HS and/or humic-bound Fe surfaces. The crystalline Fe oxides were transformed to Fe sulfides below 30 cm depth but the associated U was not transferred to these sulfides. Instead the weak associations became more important. In the wider context, since only UVI forms soluble complexes with acetate, UVI does not appear to be reduced even under the strongly reducing conditions encountered within waterlogged organic-rich soils. Initial interactions between UVI and porewater colloids appear to be weak but stronger interactions such as incorporation into Fe phases and complexation by HS occur once the colloids and associated U are removed to the solid phase. Waterlogged organic-rich soils appear to be a long-term sink for U but changing climatic conditions leading to the drying out of such soils may ultimately release U in association with smaller, more mobile organic-rich colloids.
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Chruszcz, Bryan. "Foraging and thermoregulatory behaviour of the long-eared bat (Myotis evotis) roosting in natural habitat." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ38573.pdf.
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Bowden, Robert Kirk. "Compression behaviour and shear strength characteristics of a natural silty clay sedimented in the laboratory." Thesis, University of Oxford, 1988. http://ora.ox.ac.uk/objects/uuid:9c10108d-74a7-4d97-a690-ae13a6e90aca.
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The compression behaviour, shear strength characteristics, and material properties of dense slurries and soft settled beds of natural fine-grained sediments were studied experimentally. Slurries of varying initial density, initial height, and pore fluid salinity were settled one-dimensionally, by self-weight, in the laboratory. Settling behaviour was studied in terms of slurry appearance, particle segregation, height of surface versus time, sediment surface and element settlement rates, and the redistribution of sediment with respect to height and time. Consolidation behaviour was studied in terms of sediment compressibility and pore fluid flow. Shear strength was examined "in situ" and elated to the parameters effective stress and specific volume. Instruments and techniques were developed to facilitate the measurement of low effective stresses, low strengths, and high specific volumes. A small scale sediment sampler was developed and used in an attempt to study the arrangement of particles within soft sensitive beds. The experimental results revealed numerous fundamental reasons why theoretical models of settling and consolidation are unsatisfactory when applied to dense flocculated slurries and beds of high specific volume, respectively. For the sediment studied, well-defined compressibility and shear strength relationships were observed. Pore fluid flow relationships were non-unique at high specific volumes. The compression behaviour of slurries was found to have a rational basis in terms of electrochemical forces and degrees of particle association. The experimental results are relevant to engineering practice. Recommendations are made regarding future research.
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Smith, Philip Richard. "The behaviour of natural high compressibility clay with special reference to construction on soft ground." Thesis, University of London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481683.
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Piotrowski, Stephan. "Land property rights and natural resource use an analysis of household behaviour in rural China." Frankfurt, M. Berlin Bern Bruxelles New York, NY Oxford Wien Lang, 2008. http://d-nb.info/992790964/04.
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Shapley, Mark. "The prevalence and natural history of symptoms of menstrual loss and associated health seeking behaviour." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413473.
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Elliott, Lewis Roland. "Physical activity in natural environments : importance of environmental quality, landscape type and promotional materials." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/22411.
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Physical inactivity and disconnection from natural environments threatens human health. However, research has demonstrated that natural environments potentially support health-enhancing physical activity which could confer greater physical and mental health benefits than physical activity in other types of environment. This thesis approached the study of physical activity in natural environments through three related pieces of research. Firstly, an experimental study was carried out to explore how the presence of litter in beach environments affected psychophysiological responses to exercise. Responses to exercise did not differ in littered and clean conditions but there was evidence that order effects influenced findings. Visual attention to the two scenes differed, but did not mediate differences in psychophysiological responses. Secondly, analysis of a national dataset was undertaken to explore the form and quantity of physical activity conducted within natural environments in England. A series of linear regressions revealed that higher-intensity physical activities occurred in countryside environments, but more total energy expenditure occurred in coastal environments. Thirdly, a quantitative content analysis of brochures which promote recreational walking in natural environments was conducted which investigated their use of persuasive behavioural messages. These brochures omitted behavioural techniques which may be effective at motivating inactive individuals to walk. Extending this, an online survey tested whether improving brochure content heightened intentions to walk in natural environments. By designing content based on the theory of planned behaviour, the intentions of inactive individuals to undertake walking in natural environments were increased. The findings from this thesis demonstrate that the protection of natural environments is vital for preserving and promoting active recreation and could contribute to population-level increases in physical activity with theory-based promotion in the future.
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Alison, Jennifer Alison. "From nest building to life-history patterns : does food supplementation influence reproductive behaviour of birds?" Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1351/.
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Supplementary feeding wild birds is a widespread phenomenon. Recently, non-governmental organisations have recommended that the bird-feeding public should feed wild birds throughout the breeding season. Currently, such recommendations are not supported by a large body of research findings to suggest that food supplementation has benefits for breeding birds. To investigate this further I provided two commercially available wild bird foods (peanut cake and mealworms [Tenebrio molitor]) to Blue Tits (Cyanistes caeruleus) and Great Tits (Parus major) breeding in a woodland in Central England from 2007 to 2009. Supplementary feeding significantly advanced nest construction and decreased brood provisioning rates for both species. Supplemented Blue Tits significantly decreased daily incubation activity and increased both the proportion of extra-pair young and proportion of males per brood while supplemented Great Tits decreased incubation recess lengths. Analyses of data from the British Trust for Ornithology’s Nest Record Scheme suggested that probable widespread supplementary feeding of both Blue and Great Tits in urban habitats from 1962 to 2008 influenced breeding parameters across the study period but measuring food availability across wide spatial scales remains problematic. I discuss the implications of my results within an urban garden bird feeding context and provide suggestions for future research.
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Muwanguzi, Abraham Judah Bumalirivu. "Investigating the parameters that influence the behaviour of natural iron ores during the iron production process." Doctoral thesis, KTH, Tillämpad processmetallurgi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-123063.
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In the iron production processes, sinters and pellets are mostly used as raw materials due to their consistency with respect to physical and chemical properties. However, natural iron ores, as mined, are rarely used directly as a feed material for iron processing. This is mainly due to the fact that they have small contents of iron and high concentration of impurities. Moreover, they swell and disintegrate during the descent in the furnace as well as due to low melting and softening temperatures. This work involves an investigation of the parameters that influence the use of natural iron ores as a direct feed material for iron production. Furthermore, it points out ways in which these can be mitigated so as to increase their direct use in iron production. Natural iron ore from Muko deposits in south-western Uganda was used in this study. Initially, characterisation of the physical and chemical properties was performed, to understand the natural composition of the ore. In addition, investigations were done to study the low temperature strength of the ore and its behaviour in the direct reduction zone. Also, simulations were performed with three models using the experimental data from the direct reduction experiments in order to determine the best model for predicting the direct reduction kinetics of natural iron ores. Chemical analyses showed that the Muko ore represents a high grade of hematite with an Fe content of 68% on average. The gangue content (SiO2+Al2O3) in 5 of the 6 investigated iron ore samples was < 4%, which is within the tolerable limits for the dominant iron production processes. The S and P contents were 0001-0.006% and 0.02-0.05% respectively. These can be reduced in the furnace without presenting major processing difficulties. With respect to the mechanical properties, the Muko ore was found to have a Tumble Index value of 88-93 wt%, an Abrasion Index value of 0.5-3.8 wt% and a Shatter Index value of 0.6-2.0 wt%. Therefore, the ore holds its form during the handling and charging processes. Under low temperature investigations, new parameters were discovered that influence the low temperature strength of iron oxides. It was discovered that the positioning of the samples in the reduction furnace together with the original weight (W0) of the samples, have a big influence on the low temperature strength of iron oxide. Higher mechanical degradation (MD) values were obtained in the top furnace reaction zone samples (3-25% at 500oC and 10-21% at 600oC). These were the samples that had the first contact with the reducing gas, as it was flowing through the furnace from top to bottom. Then, the MD values decreased till 5-16% at a 500oC temperature and 6-20% at a 600oC temperature in the middle and bottom reaction zones samples. It was found that the obtained difference between the MD values in the top and other zones can be more than 2 times, particularly at 500oC temperature. Furthermore, the MD values for samples with W0 < 5 g varied from 7-21% well as they decreased to 5-10% on average for samples with W0 ≥ 5 g. Moreover, the MD values for samples taken from the top reaction zone were larger than those from the middle and bottom zones. During direct reduction of the ores in a H2 and CO gas mixture with a ratio of 1.5 and a constant temperature, the reduction degree (RD) increased with a decreased flow rate until an optimum value was established. The RD also increased when the flow rate was kept constant and the temperature increased. An optimum range of 3-4g was found for natural iron ores, within which the highest RD values that are realised for all reduction conditions. In addition, the mechanical stability is greatly enhanced at RD values > 0.7. In the case of microstructure, it was observed that the original microstructure of the samples had no significant impact on the final RD value (only 2-4%). However, it significantly influenced the reduction rate and time of the DR process. The thermo-gravimetric data obtained from the reduction experiments was used to calculate the solid conversion rate. Three models: the Grain Model (GM), the Volumetric Model (VM) and the Random Pore Model (RPM), were used to estimate the reduction kinetics of natural iron ores. The random pore model (RPM) provided the best agreement with the obtained experimental results (r2 = 0.993-0.998). Furthermore, it gave a better prediction of the natural iron oxide conversion and thereby the reduction kinetics. The RPM model was used for the estimation of the effect of original microstructure and porosity of iron ore lumps on the parameters of the reduction process.QC 20130531
Sustainable Technology Development in the Lake Victoria Region
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Rhead, Rebecca Danielle. "Concern for the natural environment and its effect on pro-environmental behaviour amongst the British public." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/concern-for-the-natural-environment-and-its-effect-on-proenvironmental-behaviour-amongst-the-british-public(dabf1d8e-1c31-4fdd-b431-8e3941ce0759).html.
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Reports from the IPCC have been consistent in their findings: climate change is happening and human activity is the cause. The temperature of the earth’s climate has been steadily rising since the industrial revolution, with profoundly negative consequences for the natural environment. Britain is amongst the top 10 global contributors towards climate change, producing more CO2 per capita than China, and yet little is known about the relationship the British public have with the natural environment. Drawing upon DEFRA’s 2009 Survey of Public Attitudes and Behaviours Towards the Environment, a nationally representative sample of the UK, this study aims to (1) explore environmental attitudes in the DEFRA sample; (2) identify the types of environmental concern that exist in the UK and; (3) examine how environmental concern is associated with pro-environmental behaviours. The overall goal is to develop a better understanding this attitude-behaviour relationship. The thesis has 3 main findings. First, environmental concern is formed of three environmental attitudes: (a) a cognitive appraisal of plant and animal welfare (ecocentric attitude); (b) welfare of the human race (human-centric attitude); and (c) a prioritisation of the self, alongside dismissal of environmental problems (denial).Second, members of the British public can be assigned to one of four groups based on their environmental concern: Pro-environment, Neutral, Disengaged and Paradoxical (the latter 2 groups are apathetic towards environmental issues though in different ways).Third, when examining behaviour variation across these environmental concern groups, it was found, unsurprisingly, that membership of the pro- environmental group is strongly predictive of pro-environmental behaviour. What was surprising was that pro-environmental concern predicts a variety of behaviours, both easy and challenging (i.e. easy behaviour such as recycling household waste as well more challenging behaviour such as an increase use of public transportation over driving), whereas previous studies have typically found such behaviours to be unaffected by attitudes. Membership of the Neutral group also predicts pro-environmental behaviours, although this relationship is weaker and exists for fewer measures of behaviour. Disengaged and Paradoxical forms of concern are not significant predictors of behaviour. Upon examining the effect of socio-economic status (SES) on group membership and this attitude-behaviour relationship, it was found that SES does not moderate the attitude-behaviour relationship, but it does influence group membership. Respondents with higher SES were more likely to belong to neutral or pro-environment groups. After reviewing these findings, it is concluded that environmental attitudes do clearly predict behaviour, but a large portion of the UK population do not possess environmental attitudes strong enough to do so (the Disengaged and Paradoxical groups amount to 36% of the population). Future studies should focus on these apathetic groups in an attempt to understand them, determine effective methods of engagement and identify factors that increase the probability of members transitioning out of these groups.
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Pichler, Peter-Paul. "Natural selection, adaptive evolution and diversity in computational ecosystems." Thesis, University of Hertfordshire, 2009. http://hdl.handle.net/2299/4006.
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The central goal of this thesis is to provide additional criteria towards implementing open-ended evolution in an artificial system. Methods inspired by biological evolution are frequently applied to generate autonomous agents too complex to design by hand. Despite substantial progress in the area of evolutionary computation, additional efforts are needed to identify a coherent set of requirements for a system capable of exhibiting open-ended evolutionary dynamics. The thesis provides an extensive discussion of existing models and of the major considerations for designing a computational model of evolution by natural selection. Thus, the work in this thesis constitutes a further step towards determining the requirements for such a system and introduces a concrete implementation of an artificial evolution system to evaluate the developed suggestions. The proposed system improves upon existing models with respect to easy interpretability of agent behaviour, high structural freedom, and a low-level sensor and effector model to allow numerous long-term evolutionary gradients. In a series of experiments, the evolutionary dynamics of the system are examined against the set objectives and, where appropriate, compared with existing systems. Typical agent behaviours are introduced to convey a general overview of the system dynamics. These behaviours are related to properties of the respective agent populations and their evolved morphologies. It is shown that an intuitive classification of observed behaviours coincides with a more formal classification based on morphology. The evolutionary dynamics of the system are evaluated and shown to be unbounded according to the classification provided by Bedau and Packard’s measures of evolutionary activity. Further, it is analysed how observed behavioural complexity relates to the complexity of the agent-side mechanisms subserving these behaviours. It is shown that for the concrete definition of complexity applied, the average complexity continually increases for extended periods of evolutionary time. In combination, these two findings show how the observed behaviours are the result of an ongoing and lasting adaptive evolutionary process as opposed to being artifacts of the seeding process. Finally, the effect of variation in the system on the diversity of evolved behaviour is investigated. It is shown that coupling individual survival and reproductive success can restrict the available evolutionary trajectories in more than the trivial sense of removing another dimension, and conversely, decoupling individual survival from reproductive success can increase the number of evolutionary trajectories. The effect of different reproductive mechanisms is contrasted with that of variation in environmental conditions. The diversity of evolved strategies turns out to be sensitive to the reproductive mechanism while being remarkably robust to the variation of environmental conditions. These findings emphasize the importance of being explicit about the abstractions and assumptions underlying an artificial evolution system, particularly if the system is intended to model aspects of biological evolution.
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Ghorpade, Yashodhan. "Essays on household behaviour at the intersection of conflict and natural disasters : the 2010 floods in Pakistan." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61367/.
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This thesis examines household behaviour at the intersection of natural disasters and conflict. I structure this research around four distinct analytical chapters that use empirical microeconomic analysis to study household-level decisions and outcomes in the year following the 2010 floods in Pakistan. I first examine how does conflict affect household access to cash transfer programmes, and what mechanisms explain such effects. Using IV estimation to overcome endogeneity of conflict exposure and cash transfer receipts, I find that conflict reduces household and community level access to two large cash transfer programmes in Pakistan. The effects are driven by the likely presence of armed rebel groups who possibly resent state-led efforts to win legitimacy through social protection programmes. Next, I examine the effect of conflict on household access to remittances. I use IV estimation to overcome the endogeneity of conflict and remittance receipts and find that conflict exposure reduces household remittance receipts. This effect is driven by security threats associated with armed group presence, which threatens the operations of informal money transfer agents. Further, I find evidence for conflict negatively affecting investment-focused remittances as the effects of conflict are strongest among households more likely to use remittances for investment, than for consumption. These findings are in contrast to the macro literature that tend to view conflict as a factor that affects altruistic motives of remittances but has not examined investment motives in detail. In my third analytical chapter I examine the unintended effects of household aid receipts on violence through a mechanism that has not been studied in much detail: civilian militarisation through the purchase of guns. Using propensity score matching to overcome selection bias, I find that overall, flood relief cash transfers did not lead to any increases in household gun ownership. However recipients who own large tracts of land and live in conflict-affected areas were 8.3% more likely to acquire a gun, compared to a matched group of non-recipient households. The effects are driven by households that lived in displacement camps, which may have enhanced security concerns and the need for guns. This suggests that for groups that have low material but high security needs, exogenous increases in cash, through cash transfers, can increase the likelihood of acquiring guns for use, or for signalling, as a safety good. Finally, I examine the under-studied role of uncertainty of disasters in affecting post-disaster short-term migration decisions. I find that while flooding exposure increases the propensity to migrate, a higher level of uncertainty, represented by more anomalous floods (compared to recurring floods), decreases migration. I also develop a measure of flooding anomaly, based on the likely past exposure to floods at the community level, using satellite data on long term precipitation levels, and distance to the nearest rivers. My research examines important, but hitherto under-studied and challenging relationships that play out in complex emergencies, where many households simultaneously face flooding and violent conflict shocks. The findings are relevant for economic theory, empirical analysis and for policy.
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Uugwanga, Nekulu Selma Takatsu. "Information-seeking behaviour of Faculty of Agriculture and Natural Resources' students at Neudamm Campus, University of Namibia." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/26201.
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This study investigated the information-seeking behaviour of the Faculty of Agriculture and Natural Resources' (FANR) students at Neudamm Campus, University of Namibia (UNAM). It determined their information needs, informationseeking patterns, information use and information evaluation including preferences for information resources. In addition, it considered the challenges students encountered when accessing and using information at Neudamm Library. This was done in order to improve the delivery of information services. Taking a qualitative research approach, this study was guided by Kuhlthau's (2004) Information Search Process model which served as a theoretical framework. Data were collected from a purposively selected sample through focus group discussions that were held with undergraduate students and interviews with postgraduate students and academic staff. The key findings from this analysis are that FANR students need information to write assignments, class tests, examinations and research projects. They value both printed and online resources. However, they are frustrated by the outdated resources, shortage of printed materials, and the limited and restricted access to e-resources. When in the library, they mainly browse for books on library shelves and search for information on the internet, and rarely use library electronic databases. There is a need to train students on the formulation of search strategies and the use of library e-resources. It transpired that students seldom use advanced search strategies, instead they either type short keywords or long sentences on Google search engine. Their challenges include very noisy library study area, ineffective interlibrary loan systems and fellow students' unwillingness to share facilities such as computers. The findings indicate that the library needs to acquire the latest e-resources, provide robust information literacy training and redesign its space to increase study space that students can use to access quality information. Additionally, the university should source funds from external donors to build a state of the art library to accommodate the increasing number of FANR students.
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Hallgren, Lars. "I djupet av ett vattendrag : om konflikt och samverkan vid naturresurshantering = In the depth of a watershed : on conflict and collaboration in natural resource management /." Uppsala : Dept. of Landscape Planning, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a379.pdf.
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Barreto, Casimiro de Almeida. "Traços de personalidade e expressividade a partir de comunicação em linguagem natural para avatares em mundos virtuais 3D." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-26022016-112334/.
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Um fator relevante para a aceitação de metáforas de mundos virtuais 3D como interfaces homem máquina é a supressão do fator estranheza. Tal fator decorre da percepção de comportamentos não naturais entre as representações de usuários (avatares) e robôs (NPCs Non Playable Characters) nestes ambientes virtuais e acontece, principalmente, devido a diferenças sutís entre o comportamento esperado de um ser humano e o apresentado pelas representações virtuais (avatares). Ao conjunto de comportamentos exibidos denominamos persona. Assim, uma maneira de reduzir a barreira de estranheza entre usuários interagindo em mundos virtuais 3D é fazendo com que suas representações (avatares) tenham personas convincentes. Os seres humanos tem suas personas regidas por seus tratos emocionais. As interações com o ambiente e com outros seres humanos fornecem estímulos que modificam o estado emocional com relação ao estado de equilíbrio e, consequentemente, alteram o comportamento exterior observado. O estado emocional de equilíbrio pode ser obtido através da análise de corpo de comunicação em linguagem natural do usuário. Neste trabalho é defendida a tese de que através da análise do corpo das interações em linguagem natural de usuários nas mídias sociais é possível estabelecer um modelo de personalidade e persona que pode ser transposto para a representação dos usuários nem mundos virtuais 3D, de forma que as representações tenham comportamentos tais que reduzem o fator de estranheza. O modelo faz uso das interações recentes nas mídias sociais e das interações nos mundos virtuais 3D para determinar o estado emocional imediato e o comportamento instantâneo e é coerente com o paradigma do modelo OCC. Também é demonstrado que este modelo é evolutivo: pela análise contínua do corpo da comunicação é acompanhada a evolução da personalidade do usuário, bem como se adequa continuamente sua persona. Os traços de personalidade são analizados no modelo Big Five (Neuroticism, Extraversion, Agreeableness, Conscientiousness, Openness) e operacionalizados no modelo PAD (Personality, arousal, dominance). O modelo constrói um campo de personalidade, no espaço PAD, de tal forma que na ausência de excitação o estado emocional do avatar fica em repouso no centro deste campo. As excitações movimentam o estado ao longo dos eixos PAD e provocam mudanças no comportamento observado. A correspondência entre as mudanças de comportamento do avatar e o movimento do estado do usuário no campo emocional aumenta a concordância entre comportamento esperado e observado, reduzindo o fator de estranheza.A key factor for the acceptance of 3D virtual world mataphor as human machine interface is the suppression of the strangeness factor, which appears due the perception of non natural behaviour in representations of users (avatars) and bots (NPCs). Such perception raises mostly due to subtle differences in expected behavior for a human being and observed behavior in virtual representations (avatars and NPCs). In this work we will call persona the set of exhibited behaviors. Thus, a way of diminishing the strangeness valley is by supplying avatars with convincing personas. Human beings rule their personas with intermediation of their emotional traits. Interactions with environment and other beings supply stimuli that change the emotional state from the equilibrium situation and, consequently, change observed behavior. Idle emotional state can be determined through natural language communication corpora analysis. In this thesis we state that through the analysis of user interactions in social media it is possible to establish a model of personality and persona that can be transposed to their representation in 3D virtual worlds, so such representation exhibits behavior that minimize strangeness. The model uses recent interations of user in social media and his interactions inside the 3D virtual world to establish current behavior and is coherent with OCC paradigm. It is also demonstrated that such model is evolutive: by the continuous analysis of communication corpora the user personality behavior is updated and its persona is continually adjusted. Personality traits are analysed in the Big Five model (neuroticism, agreeableness, conscientiousness, openness) and operationalized in the PAD model (personality, arousal, dominance). A personality field is built such as in the absence of inputs, emotional state lies in the center of this field. Inputs move state along PAD axes and cause changes in the observed behavior. Correspondence between avatar behavior changes and state changes of user regarding its emotional field enhance the compliance between expected and observed behavior, reducing strangeness.
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Isaksson, Erik. "The impact of the antidepressant fluoxetine on personality traits in the isopod Asellus aquaticus." Thesis, Linköpings universitet, Biologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-159659.
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Pharmaceuticals that end up in our aquatic environment continue to increase. In recent years, serotonin re-uptake inhibitors (SSRI) have increased in usage as it is considered safer than other substances to treat depression. Fluoxetine (Prozac) is a widely used anti-depressant that commonly leak out after human use to aquatic environments. Although widely spread, the impact of fluoxetine on aquatic animals in is poorly investigated. The objective of this study was to see if fluoxetine impacts the behaviour of freshwater isopod Asellus aquaticus. Asellus aquaticus were exposed to an ecologically relevant concentration of fluoxetine for 28 days. Through a series of behavioural assays designed to measure the personality traits boldness, activity, exploration and escape behaviour, Asellus aquaticus responses were investigated. A. aquaticus can differ greatly in phenotype, from non-pigmentation to dark pigmentation. Further objective was therefore to investigate if pigmentation correlated with any of the measured behavioural responses, due to potential across-reaction between serotonergic and melatoneric systems. I found that fluoxetine reduced boldness, but had no effect on activity, exploration or escape behaviour. Furthermore, I observed no correlation between pigmentation and behaviour measured in fluoxetine exposed, or control animals. These results indicate that fluoxetine at low levels affect boldness of wild A. aquaticus but no other personality traits explored. However, other research contradicts these results and show that fluoxetine can affect a range of behaviours. Taken together fluoxetine can have ecological impact on aquatic environments. Hence, our residual pharmaceuticals can have ranging effects.
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Tapper, Josefine, and Cajsa Baars. "Put your head in the sand or lose a grand? : A natural experiment of the ostrich effect and the disposition effect." Thesis, Linköpings universitet, Nationalekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-150095.
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This thesis presents an attempt to find evidence of the ostrich effect and the disposition effect, as well as individual differences in self-assessed financial knowledge and its effect on these biases. The ostrich effect refers to the tendency to deliberately avoid information that might be negative, by "sticking your head in the sand". The disposition effect refers to people who hold on to losing assets too long while selling winning ones too early. The two effects were examined through a natural experiment which emerged from the stock market crash that occurred February 5th, 2018. The data was collected during an internship at Länsförsäkringar AB and originates from the usage of Länsförsäkringar's application Sparnavigatorn, where customers can manage their savings. The customers login activity and number of placed sales orders were observed. The data material is unique, and the study enabled a unique presentation of real life behaviour within a financial context and an analysis of whether individual differences affect behaviour. To our knowledge, neither the ostrich effect nor the disposition effect have earlier been examined through a large scale natural experiment. The results show no significant indication of the ostrich effect, but rather a relatively constant login activity not affected by the stock market crash. Furthermore, they show a contradictory reaction to what the disposition effect suggests, meaning the respondents place more sales orders during the stock market fall than at the time before and after. The results imply that further research needs to be done to either reject or confirm the existence of the ostrich effect and the disposition effect.
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Crawford, Alistair, and n/a. "Bad Behaviour: The Prevention of Usability Problems Using GSE Models." Griffith University. School of Information and Communication Technology, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20061108.154141.
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The aim of Human Computer Interaction or HCI is to both understand and improve the quality of the users' experience with the systems and technology they interact with. Recent HCI research requirements have stated a need for a unified predictive approach to system design that consolidates system engineering, cognitive modelling, and design principles into a single 'total system approach.' At present, few methods seek to integrate all three of these aspects into a single method and of those that do many are extensions to existing engineering techniques. This thesis, however proposes a new behaviour based approach designed to identify usability problems early in the design process before testing the system with actual users. In order to address the research requirements, this model uses a new design notation called Genetic Software Engineering (GSE) in conjunction with aspects of a cognitive modelling technique called NGOMSL (Natural GOMS Language) as the basis for this approach. GSE's behaviour tree notation, and NGOMSL's goal orientated format are integrated using a set of simple conversion rules defined in this study. Several well established design principles, believed to contribute to the eventual usability of a product, are then modelled in GSE. This thesis addresses the design of simple interfaces and the design of complex ubiquitous technology. The new GSE approach is used to model and predict usability problems in an extensive range of tasks from programming a VCR to making a video recording on a modern mobile phone. The validity of these findings is tested against actual user tests on the same tasks and devices to demonstrate the effectiveness of the GSE approach. Ultimately, the aim of the study is to demonstrate the effectiveness of the new cognitive and engineering based approach at predicting usability problems based on tangible representations of established design principles. This both fulfils the MCI research requirements for a 'total system approach' and establishes a new and novel approach to user interface and system design.
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Mak, Chun Fai Patric. "An investigation into the behaviour of fibre reinforced natural gas powered vechicle (NGV) pressure cylinders under impact loading." Thesis, University of Newcastle Upon Tyne, 1998. http://hdl.handle.net/10443/782.
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Commonly encountered accidental impact, e.g. due to roadway stone hitting, is detrimental not only because it can produce apparent surface defects, but also because barely visible impact damage (BVID) can be induced inside the material, which is not easy to detect by routine inspection. Reliable prediction of the amount of damage of this type induced under known service conditions is particularly important. Therefore, this type of impact was chosen as the focus of the present investigation. A combination of experimental techniques and finite element modelling was used to explore the behaviour of a fibre reinforced natural gas powered vehicle (NGV) pressure cylinder subjected to a low energy impact. In order to identify the modes of failure and understand the structural response, quasi-static indentation tests were carried out on sections of composite pipes and of a composite pressure cylinder. Delamination and matrix cracking were established to be the two major failure modes induced by indentation. Experimental findings were used as a basis for assessing the validity of the modelling approach. Thick shell and three dimensional finite element models were developed using PAFEC, a general purpose finite element code for dynamic and static analysis. It established that the composite pressure cylinder under this type of impact behaves quasi-statically, i.e. the impact phenomenon predominately excites low frequency response. Repeated impact was considered in order to extend the study to include the impact behaviour of a cylinder with pre-existing damage. It was found that a bulging effect was produced in the pressure cylinder at the impact site, where a weak spot was created due to fibre breakage. A fully three dimensional finite element model with static analysis was developed to investigate the damage and material degradation during the BVID phenomenon. The contact pressure distribution based on the Hertzian contact' relationship was applied. Failure mode identification criteria proposed by Hashin (1980) and Chang and Springer (1986) were used to establish the mode and extent of damage in the composite cylinder under quasi-static loading. The predicted failure modes agreed well with the experimental results. Finally, the present study sets out the methodology allowing systematic design of structures having optimal impact tolerance. Based on the findings of this project, suggestions for the improvement of impact resistance of NGV cylinders were given in Chapters ix.
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Spicer, Esme Marelien. "The low-pressure partial-melting behaviour of natural boron-bearing metapelites from the Mt Stafford area, Central Australia." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/18070.
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Thesis (DSc)--University of Stellenbosch, 2011.ENGLISH ABSTRACT: This study has examined the 3 kbar partial melting behaviour of 4 metapelites collected from the highest grade rocks occurring below the anatectic zone of the Mt Stafford area, Arunta Inlier, central Australia. In this area, metasediments are interpreted to have undergone partial melting within the andalusite stability field, possibly as a result of a lowering of the metapelite solidus by the presence of boron in the rocks. Two of the samples were two mica metapelites (MTS70 and MTS71) that both contained significant quantities of tourmaline and were thus boron enriched. The other two samples were biotite metapelites. One of these rocks contains only a trace of tourmaline (MTS8) and the other is tourmaline free (MTS7). Despite expectations that muscovite in the two mica samples would break down via a subsolidus reaction, muscovite was stable to above 750 C due to the incorporation of Ti, phengitic and possibly F components into its structure. Between 750 and 800 C, muscovite melted out completely via a coupled muscovite + biotite fluid-absent incongruent reaction. In the most mica-rich sample this reaction produced ~ 60 % melt at 800 C. In the biotite metapelites, biotite melting began at a temperature below 800 C and was accompanied by very modest melt production at this low temperature. In contrast to the two mica metapelites, the main pulse of melt production in these samples occurred at a temperature between 850 and 950 C. In both these samples biotite + melt coexistence persisted for a temperature range in excess of 150 C, and in MTS8, biotite was still in the run products at 950 C. The very refractory nature of these evolved biotite compositions is most likely a consequence of both the presence of a Ti buffering phase in the assemblage (ilmenite) and the essentially plagioclase-free nature of the starting compositions. Under the fluid-absent conditions of this study tourmaline is clearly a reactant in the partial melting process, but does not appear to shift the fluid-absent incongruent melting reactions markedly. Neither quartz, nor andalusite was completely consumed in the melting reactions, indicating the metastable persistence of andalusite to higher than the wet solidus temperatures. The assemblages do not change much with increasing temperature and mimic the field relationships. The fluid-absent melting experiments indicated that the main pulse of melting occurred between 850 and 950 °C, significantly higher than indicated by the field evidence of 600 to 675 °C, therefor disequilibrium in the experiments can not be ruled out. The presence of a fluid during partial melting at Mt Stafford provides therefor an explanation of the low temperatures at which melting occurred.
AFRIKAANSE OPSOMMING: Die 3 Mpa vloeistof-vrye gedeeltelike smelting van 4 metapeliete, gekollekteer van die hoogste graad rotse net onder die anatektiese sone van die Mt Stafford area, Arunta inlêer, sentraal Australië, is bestudeer. Die metapeliete van hierdie area word geinterpreteer dat hulle gedeeltelike smelting in die andalusiet stabiliteitsveld ondergaan het, moontlik as 'n resultaat van die verlaging van die metapeliet solidus as gevolg van die teenwoordigheid van boor. Twee van die monsters bestudeer was twee-mika metapeliete (MTS70 en MTS71) met beduidende hoeveelhede toermalyn en is dus boor-verryk. Die ander twee monsters was biotiet metapeliete, waarvan een spoorhoeveelhede toermalyn (MTS8) bevat het en die ander toermalyn vry was (MTS7). Ten spyte van verwagtinge dat muskoviet in die twee mika monsters sou afbreek via 'n subsolidus reaksie, was dit stabiel tot bo 750°C as gevolg van die vervanging van Ti, fengitiese en moontlik F komponente in die muskoviet struktuur. Tussen 750 en 800°C het muskoviet heeltemal gesmelt deur die vloeistof-vrye gekoppelde muskoviet+biotiet reaksie. In die monster met die meeste mika het hierdie reaksie ~ 60 % gesmelt by 80°C en lae hoeveelhede smelt is by hierdie lae temperature geproduseer. In kontras met die twee-mika metapeliete het die hoof puls van smeltproduksie in hierdie monsters plaasgevind tussen 850 en 950°C. In beide hierdie monsters het biotiet+smelt 150°C. Biotiet was steeds ongesmelt in MTS8 by 950°. Die hoë refraktoriese natuur van hierdie biotiet samestellings is hoogs waarskynlik 'n gevolg van die teenwoordigheid van 'n Ti-bufferende fase (ilmenite) en die afwesigheid van plagioklaas in die begin samestellings. Toermalyn is duidelik 'n reaktant in hierdie vloeistof-vrye gedeeltelike smelting studie, maar dra nie beduidend by tot die verlaging van die inkongruente smeltingsreaksies nie. Nie kwarts of andalusiet het heeltemal gesmelt oor die temperatuurreeks nie, wat aandui dat die andalusiet stabiel is by temperature hoër as die nat solidus. Die mineraalverspreidings verander nie veel met verhoging in temperatuur nie en mimiek dus die veld verwantskappe. Die vloeistof-vrye smeltings eksperimente het aangedui dat die hoofpuls van smelting tussen 850 en 950°C geskied het, wat aansienlik hoër is soos aangedui uit die veldgetuienis van 600 tot 675°C, dus is die moontlikheid van disekwilibrium gedurende die eksperimente 'n moontlikheid. Die moontlikheid dat vloeistof teenwoordig was tydens die smeltproses by Mt Stafford verskaf dus 'n oplossing vir die lae temperature wat tydens smelting bereik is.
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Coetzee, Gerrit. "The mechanical and volumetric behaviour of sisal fibre reinforced concrete blocks." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80010.
Full textAbstract:
Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Natural fibre reinforced concrete (NFRC) is a type of concrete that has become of particular interest in recent years, due to its potential for being used as a sustainable and economically viable building material. Natural fibres are often cheap and widely available in developing nations. Sisal is one such fibre predominantly grown in Brazil and has been identified as having the potential to be commercially cultivated in Southern Africa. The durability of sisal fibres in a cementitious environment tends to be adversely affected due to the high alkalinity of pore water and the presence of calcium hydroxide. This research dealt with the use of sisal fibre reinforced concrete (SFRC) blocks. It focused on the mechanical and volumetric properties of blocks with varying fibre and condensed silica fume content (CSF). Two different SFRC blocks were produced (solid and hollow) using an average fibre length of 10 mm. Two matrix types were used: one using a 70:30 cement:fly-ash ratio and another using a 60:30:10 cement:fly-ash:CSF ratio by weight. Samples of each matrix type were prepared with 0, 0.5 and 1% fibre content by volume. Hollow blocks were tested for compressive strength and capillary water absorption, while solid blocks were tested for compressive strength, flexural strength, capillary water absorption, dimensional stability, drying shrinkage, density, total water absorption and void content. All tests were performed on samples with an age of 28 days. Solid block compressive tests were also performed on samples with an age of 7 days. The hollow blocks had significantly lower average compression strength than the solids, but an increase in fibre content caused a slight increase in strength. For solid blocks, it was found that the addition of natural fibres decreases the strength, although a partial substitution of cement with CSF, in conjunction with fibres, did increase the strength relative to blocks without CSF. The flexure strength was also lowered somewhat by the addition of fibres, but an increase in ductility was noted, although not quantified. The addition of CSF to fibre-containing blocks led to an increase in capillary water absorption, but a decrease in absorption through immersion. This shows that the addition of CSF does significantly alter the pore system of a cementitious matrix reinforced with natural fibres. Also, the dimensional stability increased with the addition of CSF and fibres. The same can be said for drying shrinkage. Even though an increase in fibre and CSF caused samples to shrink more under drying, they were more stable under cycles of wetting and drying. It was concluded that the addition of fibres to a matrix had a detrimental effect on strength, although ductility did increase. The volumetric properties of concrete were also adversely affected by the addition of fibres, although dimensional stability was improved. The partial substitution of cement with CSF did improve many of the mechanical and volumetric properties of samples containing sisal fibre.
AFRIKAANSE OPSOMMING: Natuurlike vesel bewapende beton (NVBB) is ’n tipe beton wat onlangs heelwat belangstelling ontlok het weens die potensiaal om gebruik te word as ‘n volhoubare en ekonomiese haalbare boumateriaal. Natuurlike vesels is dikwels baie goedkoop en wyd beskikbaar in ontwikkelende lande. Sisal is een so ‘n vesel wat verkry word vanaf die blare van ’n garingboom. Die plant word hoofsaaklik in Brasilië verbou en is al uitgewys weens sy potensiaal om op kommersiële skaal in Suidelike Afrika verbou te word. Die duursaamheid van sisal vesels is geneig om nadelig geaffekteer te word in die teenwoordigheid van kalsium hidroksied en ’n hoë-alkali omgewing, soos gevind in die porie-water van beton. Hierdie navorsing handel oor die gebruik van sisal vesel bewapende beton (SVBB) boublokke. Dit fokus op die meganiese- en duursaamheids eienskappe van blokke met verkillende inhoude van vesel en gekondenseerde silika dampe (GSD). Twee verskillende SVBB blokke is geproduseer (solied en hol) deur gebruik te maak van 10 mm vesels. Twee matriks tipes is gebruik: een met ’n 70:30 sement:vliegas verhouding en een met ’n 60:30:10 sement:vliegas:GSD verhouding, volgens gewig. Blokke van elke matriks tipe is geproduseer met 0, 0.5 en 1% vesel inhoud, volgens volume. Hol blokke is getoets vir druksterkte en kapillêre water absorpsie, terwyl soliede blokke getoets is vir druksterkte, buigsterkte, kapillêre water absorpsie, dimensionele stabiliteit, krimp onder uitdroging, digtheid, totale water absorpsie en luginhoud. Alle toetse is gedoen op blokke met ’n ouderdom van 28 dae. Druktoetse is ook gedoen op soliede blokke met ’n ouderdom van 7 dae. Die hol blokke het ’n aansienlike laer gemiddelde druksterkte as die soliede blokke gehad, maar ’n toename in veselinhoud het gelei tot ’n effense verhoging in druksterkte. ’n Toename in veselinhoud van soliede blokke het gelei tot ’n afname in druksterkte, alhoewel ’n gedeeltelike vervanging van sement met GSD gelei het tot ’n hoër druksterkte vir blokke met vesels. Die buigsterkte van soliede blokke het ook afgeneem met ’n verhoging in veselinhoud. ’n Verhoging in duktiliteit is waargeneem met ’n toename in veselinhoud, alhoewel dit nie gekwantifiseer is nie. Die toevoeging van GSD tot blokke bevattende vesels het gelei tot ’n verhoging in kapillêre water absorpsie, maar ’n verlaging in totale water absorpsie. Dit kan daarop wys dat die toevoeging van GSD die poriestelsel van NVBB noemenswaardig verander. Beide die dimensionele stabiliteit en krimp onder uitdroging het toegeneem met die toevoeging van GSD en vesels tot die blokke. Dus, die toevoeging het gelei tot ’n hoër krimpvervorming tydens uitdroging en ’n hoër stabiliteit tydens nat/droog siklusse. Daar is tot die gevolgtrekking gekom dat die toevoeging van sisal vesels tot ’n beton blok oor die algemeen ’n negatiewe effek het op sterkte, alhoewel duktiliteit toeneem. Die volumetriese eienskappe van beton word ook negatief geaffekteer met die toevoeging van sisal vesels, alhoewel dimensionele stabiliteit verbeter. Die gedeeltelike vervanging van sement met GSD lei tot die verbetering van beide meganiese en volumetriese eienskappe van beton blokke wat sisal vesels bevat.