To see the other types of publications on this topic, follow the link: Light-Behaviour.
Dissertations / Theses on the topic 'Light-Behaviour'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Light-Behaviour.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Al-Akaidi, Marwan Muhammad Hussain. "Prediction of the behaviour of light in light pipes for LCD instrument clusters." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/26992.
Full textAbstract:
Liquid Crystal Displays are commonly used in automotive dashboards. The back lighting necessary for a Liquid Crystal Display (LCD) can be achieved by the use of a light source and a light box, light pipe, or a diffusing screen. The space constraints of an automobile dashboard often mean that the light pipe is the most suitable method of illumination. At present an optimum design for the light pipe is obtained by a "Cut and Try" approach in which several light pipes are usually moulded and tested before a satisfactory candidate is found. This thesis reports on experimental and theoretical work to improve the legibility and readability of 'on' and 'off' segments of liquid crystal displays and to automate the design of the light pipes using Computer-Aided Design.
2
Lee, David Tsu-Long. "Behaviour of corrosion-protection coatings in light alloys." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:bfbcec97-5f42-4eb3-aaec-ba5443e953ba.
Full textAbstract:
Anionic chromate (VI) compounds are inhibitive pigments and have been effectively incorporated into organic coatings to protect metal surfaces from aggressive ions, but their risk as a human carcinogen and being harmful to the environment has led to the search of suitable alternatives. Aluminium alloy, AA2024-T3, is the substrate metal alloy used in the experiments and can be found in aircraft fuselage structures due to their high strength-to-weight ratio. However, the presence of intermetallic particles increases susceptibility to localised corrosion. To investigate the protection mechanisms of primers on light alloys, many different factors must be taken into account; from aluminium alloy corrosion processes, the effects of intermetallic additions to coating chemistry, morphology and inhibitive pigments. The chemical environment in which the samples are tested in will also affect the corrosion mechanisms of the alloy as well as the performance of the coatings and release of pigments. It will be important to consider which factors are operating under particular conditions so that experimental results can then be best interpreted. As part of this project, potentiodynamic polarisation, electrochemical impedance spectroscopy and electrochemical noise analysis have been used to investigate the protective mechanisms in which chromate-based paints protect against corrosion and UV-Visible spectroscopy, scanning acoustic microscopy and optical microscopy have been used to investigate pigment release mechanism to identify what characteristics are important when developing new primers.
3
Thompson, Claire Elisabeth. "The effects of light intensity on turkey eyes and behaviour." Thesis, University of Leeds, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250913.
Full text
4
Maddocks, Samantha Annice. "The effect of light quality on avian behaviour and welfare." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364870.
Full text
5
Flajšmanová, Jana. "Behaviour of Objects in Structured Light Fields and Low Pressures." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-444991.
Full textAbstract:
Studium chování opticky zachycených částic nám umožňuje porozumět základním fyzikálním jevům plynoucím z interakce světla a hmoty. Předkládaná práce podává vysvětlení zesílení tažné síly působící na opticky svázané částice ve strukturovaném světelném poli, tzv. tažném svazku. Ukazujeme, že pohyb dvou opticky svázaných objektů v tažném svazku je silně závislý na jejich vzájemné vzdálenosti a prostorové orientaci, což rozšiřuje možnosti manipulace hmoty pomocí světla. Následně se práce zaměřuje na levitaci opticky zachycených částic ve vakuu. Představujeme novou metodologii na charakterizaci vlastností slabě nelinearního Duffingova oscilátoru reprezentovaného opticky levitující částicí. Metoda je založena na průměrování trajektorií s určitou počáteční pozicí ve fázovém prostoru sestávajícím z polohy a rychlosti částice a poskytuje informaci o parametrech oscilátoru přímo ze zaznamenaného pohybu. Náš inovativní postup je srovnán s běžně užívanou metodou založenou na analýze spektrální hustoty polohy částice a za využití numerických simulací ukazujeme její použitelnost i v nízkých tlacích, kde nelinearita hraje významnou roli.
6
Tinkler, E. "Behaviour and ecology of the light-bellied goose wintering in Ireland." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487463.
Full textAbstract:
The behaviour, ecology and energetics of the East Canadian High Arctic light-bellied brent goose (Bronto bernicla hrota) was investigated to determine winter feeding Site selection on Strangford Lough, Co Down, Northern Ireland. The seasonal use of mudflats, saltmarsh and improved pasture was assessed to evaluate the role these habitats play in fulfilling the energy requirements of the geese throughout the wintering period. Brent geese began feeding on eelgrasses Zostera spp. on arrival in late August early September. Single adults arrived first and were in poorer physical condition than paired or family adults which arrived later. Differences in distribution of feeding and physical condition suggests that families are more able than paired or single birds to maintain access to a better quality/quantity food supply over the winter. The activity budget and net energy results highlight the importance of Zostera spp. and the energetic constraints faced by brent geese feeding on Zostera spp. over winter. Position-sensitive radio telemetry provided an accurate and effective method for determining the time spent feeding by individual brent geese throughout the 24hour period in late winter early spring. At this time brent geese rely heavily on the contribution from improved pasture in order to meet their daily net energy . requirement prior to spring migration. Brent geese engaged in night time feeding, exclusively on the mudflats. Night-time feeding occurred from October to April, peaking in mid-winter. This activity appears to be a strategy for the geese to meet their energy requirements during shorter, colder winter days. Feeding on saltmarsh vegetation occurs subsequent to the depletion of Zostera spp. and at a critical time in mid winter and is constrained by the availability and quality, rather than quantity, of the food resource. The study's findings would suggest that for the future conservation of the geese the main conservation requirements for the population is the maintenance of intertidal habitat quality together with the creation of inland refuaes in areas where there may be conflict with agricultural interests.
7
Lacroix, Daniel. "Behaviour of Light-frame Wood Stud Walls Subjected to Blast Loading." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24339.
Full textAbstract:
Deliberate and accidental explosions along with the heightened risk of loss of life and property damage during such events have highlighted the need for research in the behaviour of materials under high strain rates. Where an extensive body of research is available on steel and concrete structures, little to no details on how to address the design or retrofitting of wood structures subjected to a blast threat are available. Studies reported in the literature that focused on full scale light-frame wood structures did not quantify the increase in capacity due to the dynamic loading while the studies that did quantify the increase mostly stems from small clear specimens that are not representative of the behaviour of structural size members with defects. Tests on larger-scale specimens have mostly focused on the material properties and not the structural behaviour of subsystems. Advancements in design and construction techniques have greatly contributed to the emergence of taller and safer wood structures which increase potential for blast threat. This thesis presents results on the flexural behaviour of light-frame wood stud walls subjected to shock wave loading using the University of Ottawa shock tube. The emphasis is on the overall behaviour of the wall subsystem, especially the interaction between the sheathing and the studs through the nailed connection.
The approach employed in this experimental program was holistic, where the specimens were investigated at the component and the subsystem levels. Twenty walls consisting of 38 mm x 140 mm machine stress-rated (MSR) studs spaced 406 mm on center and sheathed with two different types and sheathing thicknesses were tested to failure under static and dynamic loads. The experimental results were used to determine dynamic increase factors (DIFs) and a material predictive model was validated using experimental data. The implications of the code are also discussed and compared to the experimental data.
Once validated, an equivalent single-degree-of-freedom (SDOF) model incorporating partial composite action was used to evaluate current analysis and design assumptions. The results showed that a shock tube can effectively be used to generate high strain-rate flexural response in wood members and that the material predictive model was found suitable to effectively predict the displacement resulting from shock wave loading. Furthermore, it was found that current analysis and design approaches overestimated the wall displacements.
8
Johansson, Carin. "The behaviour of light weight wooden joist floors at low frequiencies." Licentiate thesis, Luleå, 1994. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25979.
Full text
9
Parmar, Chetan Kumar. "Spectroscopic and light stability behaviour of photographic dyes at oil aqueous interfaces." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249525.
Full text
10
Arab, Tala Mustapha. "The effect of supplementary light on the behaviour and performance of cattle." Thesis, Bangor University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245311.
Full text
11
Watz, Johan. "Winter behaviour of stream salmonids: effects of temperature, light, and ice cover." Licentiate thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-26809.
Full textAbstract:
In boreal streams, stream salmonids typically face low water temperatures and variable ice conditions during winter, and thus stream salmonids are expected to use different behavioural strategies to cope with these environmental conditions. The studies presented in this thesis explore how temperature, light intensity, and surface ice affect salmonid behaviour, with focus on drift-feeding and ventilation rates. The first paper reports results from a laboratory study designed to measure prey capture probabilities and reaction distances of drift-feeding Atlantic salmon, brown trout, and European grayling at light intensities simulating daylight and moonlight at seven temperatures ranging from 2 to 11°C. There was a positive relationship between water temperature and prey capture probability for all three species at both light levels, but the temperature-dependence did not scale according to the Metabolic Theory of Ecology. Reaction distance was also positively related to temperature for the three species, which may explain the temperature effects on prey capture probability. The results from this study should be of interest for those working with energetic-based drift-foraging models. In the second paper, the effects of ice cover on the diel behaviour and ventilation rate of brown trout were studied in a laboratory stream. Ice cover is believed to afford protection against endothermic predators, and thus the need for vigilance should be reduced under ice cover. This hypothesis was tested by observing ventilation rates at night, dawn, and during the day in the presence and absence of real, light-permeable surface ice. Further, trout were offered drifting prey during the day to test if ice cover increased daytime foraging activity. Ice cover reduced ventilation rates at dawn and during the day, but not at night. Moreover, trout made more daytime foraging attempts in the presence of ice cover than in its absence. These results suggest that ice cover affects the behaviour of brown trout and presumably has a positive effect on winter survival. Global warming, by reducing the extent or duration of surface ice, may therefore have negative consequences for many lotic fish populations in boreal streams.BAKSIDESTEXT In boreal streams, salmonids typically face low water temperatures and variable ice conditions from autumn to spring. The studies presented in this thesis explore how temperature, light intensity, and ice cover affect salmonid behaviour, with focus on drift-feeding and ventilation rates. In Paper I, drift-foraging was studied at light intensities simulating daylight and moonlight at seven temperatures ranging from 2 to 11°C. There was a positive relationship between temperature and foraging success at both light levels, but the temperature-dependence did not scale according to the Metabolic Theory of Ecology. Moreover, reaction distance was positively related to temperature. In Paper II, the effects of ice cover on behaviour and ventilation rate of brown trout were studied. Ice cover is believed to afford protection against predators, and thus the need for vigilance should be reduced under ice. This hypothesis was tested by observing ventilation rates at night, dawn, and during the day in the presence and absence of surface ice. Ice cover reduced ventilation rates and increased daytime foraging activity, suggesting that ice cover presumably has a positive effect on winter survival.
12
Valdimarsson, Sveinn Kari. "Effect of temperature and light on overwintering behaviour of juvenile Atlantic salmon." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264110.
Full text
13
Holtmann, Sven. "Goldstone mode effects and critical behaviour of QCD with 2 light quark flavours." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971814430.
Full text
14
Cerveira, Ana M. "Geographic variation in behaviour and dim light adaptation in Cyrba algerina (Araneae, Salticidae)." Thesis, University of Canterbury. Biological Sciences, 2007. http://hdl.handle.net/10092/1489.
Full textAbstract:
Cyrba algerina is a salticid (Salticidae) spider that lives on the undersides of stones. Two populations were studied, Sintra and Algarve (Portugal), and shown to have similar phenology but different dominant prey. Life cycle in the laboratory was similar for the two populations, but Sintra matured at larger size than Algarve individuals, with these differences potentially having a genetic basis. Sintra individuals used prey-specific prey-capture behaviour against allopatric (Oecobius amboseli) and sympatric (O. machadoi, Trachyzelotes bardiae) spider and insect (bristletails) species. In contrast, Algarve C. algerina only adopted specialised capture behaviour against bristletails. Sintra, but not Algarve, individuals responded to the odour of O. machadoi and T. bardiae, and showed preference for T. bardiae over O. machadoi. Interpopulation variation in the use of specific prey-capture behaviour and in sensitivity to odour cues from prey is directly related to the prey available to individuals from each population, suggesting local adaptation to local prey. Preference for oecobiids seems to be controlled by an experiencetriggered developmental switch. The optics and histology of C. algerina’s principal eye suggest that living in a microhabitat with dim ambient light has favoured sensitivity at the expense of spatial acuity. Short focal length, reduced power of the eye’s diverging lens, and wide, contiguous rhabdomeres, seem to minimise the visual constraints imposed by the low light levels in C. algerina’s microhabitat. While relying solely on vision, C. algerina can detect, identify and capture prey in dim-light conditions under which other salticids perform poorly. C. algerina’s behaviour suggest use of temporal summation to improve its visual performance in dim light.
15
Tinsley, Matthew. "Experimenter familiarity and light intensity effects on open field behaviour of Rattus norvegicus /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09SPS/09spst592.pdf.
Full text
16
Schmidt, Nico [Verfasser]. "Phase transformation behaviour of polylactide probed by small angle light scattering / Nico Schmidt." Paderborn : Universitätsbibliothek, 2020. http://d-nb.info/1209601370/34.
Full text
17
Lomas, Caroline Anne. "The effect of supplementary light on the behaviour, physiology and productivity of cattle." Thesis, Bangor University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239841.
Full text
18
Hardisty, Paul Edward. "Characterization, occurrence and behaviour of light non-aqueous phase liquids in fractured rock." Thesis, University of London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244612.
Full text
19
Richardson, Gillian. "The effect of light-induced eye damage on the behaviour of Nephrops norvegicus." Thesis, University of Leicester, 1996. http://hdl.handle.net/2381/34210.
Full textAbstract:
Nephrops norvegicus is susceptible to irreversible eye damage following exposure to daylight when brought to the surface during fishing operations. This study investigated the significance of blinding on the behaviour of undersized eye-damaged N. norvegicus after being returned to the sea bed. Field-based and laboratory-based experiments showed that sighted and blinded N. norvegicus possess similar 24 h nocturnal activity rhythms. In the laboratory, N. norvegicus performed a higher level of activity after they were blinded but in the field there was no significant difference in activity levels of the sighted and blinded individuals. The effect of blinding on the predator avoidance behaviour of N. norvegicus was assessed using either the presence or odour of a predatory fish (cod, Gadus morhua). Avoidance behaviour of both sighted and blinded N. norvegicus was elicited by both types of cod stimuli, but blinded N. norvegicus were affected to a lesser extent than the sighted ones. It was also shown that avoidance behaviour of both sighted and blinded N. norvegicus is elicited equally by a predator species (G. morhua) and a non-predatory species (Pollachius virens). Contests between individual N. norvegicus were studied in the laboratory and a full description is given of all types of the agonistic behaviour performed. The relative status of two opponents was unaffected if either the dominant or the subordinate opponent was blinded. The duration and content of contests were largely unchanged after blinding one opponent. There was no evidence from laboratory-based experiments, that blinding has any effect on the ability of N. norvegicus to gain shelter and to locate food items. It was also shown that blinded N. norvegicus are able to find a baited creel in a laboratory situation. These results provide evidence to suggest that, in respect of these important behaviours, there is no major difference between sighted and blinded N. norvegicus.
20
Prayitno, Dwi Sunarti. "The effects of colour and intensity of light on the behaviour and performance of broilers." Thesis, Bangor University, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387208.
Full text
21
Greenwood, Verity Jane. "The effects of the artificial light environment on avian behaviour and physiological indicators of stress." Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274670.
Full text
22
Khan, Akram. "Composite Behaviour of Normalweight and Lightweight Concrete Panels With Partially Embedded Light-Gauge Steel Channels." Thesis, University of New Brunswick, 2010. http://hdl.handle.net/1882/1092.
Full textAbstract:
This research investigates prefabricated light-gauge steel and concrete panels using
reliable and commercially viable shear connectors. An analytical and experimental
investigation was undertaken to study the flexural behaviour of light-gauge steel and
concrete composite panels under uniform pressure. Normalweight and lightweight
concrete panels were fabricated by embedding 16-gauge 41 mm x 203 mm steel channel
sections (running parallel to each other) to a depth of 38 mm into a 64 mm thick
concrete slab. Push-out tests were also conducted to evaluate the efficiency of three
types of shear connection mechanism; natural surface bonding, predrilled holes, and
punched holes. Only two types of shear connectors (predrilled holes and punched holes)
were used in the full-scale panel specimens.
Results show that the predrilled holes and punched holes provide full shear transfer
between the steel and concrete. The ultimate load carrying capacity of the lightweight
concrete panels exhibited similar behaviour to the normalweight concrete panels. All the
panels exhibited good load carrying capacity and ductility, and satisfied the
serviceability limit state of deflection. Thus, the proposed panels present a potential for
a commercially viable composite floor system for building construction utilizing a
maximum span of 2330 mm.
23
Kirk, Richard Ernest. "Investigation of the plasma behaviour in the dense plasma focus using laser light scattering techniques." Thesis, Royal Holloway, University of London, 1985. http://repository.royalholloway.ac.uk/items/9ff4cc6f-3a85-428f-84e4-a402d57b03f3/1/.
Full textAbstract:
The frequency spectrum of density fluctuations in a Plasma Focus device has been investigated by Thomson scattering of laser light. A ruby laser scattering diagnostic has been developed to enable the co-operatively scattered ion feature, Si(k,w) to be measured simultaneously along different density fluctuation k vectors. Data derived from this apparatus is interpreted in terms of the time and space variations of local plasma parameters such as electron and ion temperatures, drift velocity, bulk velocity and level of turbulence. The total scattered intensity, Si(k) is shown to depend on the direction in whichthe fluctuations are sampled by the scattering geometry, with scattered intensities along a Je vector parallel to the current flow enhanced considerably above thermal levels. The data is found to be most satisfactorily interpreted in terms of a double radial shell model of the plasma, each shell with its own characteristic particle temperatures, density, drift and bulk velocity. At peak compression of the pinch onto the z-axis of symmetry for example, the core plasma has typically electron and ion temperatures Te = 200 eV, Ti = 250 eV respectively, while the outer sheath region exhibits a shot to shot variation in the temperature structure, with Te=2.3 keV, Ti=850 eV and Te = L.65 keV, Ti = 1.4 keV respectively. An examination of the relative enhancementand broadening of Si(k,w) along the various k-vectors has been interpretedin terms of current driven turbulence. The various mechanisms for inducing turbulence have been considered and lower-hybrid drift, electron-cyclotron drift and ion acoustic instabilities are thought to play a role in the various phases of the plasma discharge. The development of the multiple Je scattering diagnostic has overcome the ambiguity in interpreting scattering results from an irreproduceable inhomogeneous plasma. This problem has restricted the interpretation of the results in previous scattering experiments on the Plasma Focus using single Je vector scattering arrangements.
24
Singh, Prasoon. "Investigation of sex-based differences inresponses to artificial light of the greater waxmoth (Galleria mellonella)." Thesis, Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-45257.
Full textAbstract:
Artificial light at night (ALAN) is becoming a greater threat to nocturnal species. Aside from the overall increase in light output, replacing outdated monochromatic street lighting with light-emitting diode (LED) lights with a broad emission spectrum could raise this issue more. However, studies evaluating the effect of artificial lights on nocturnal species, such as moths, are scarce. This study examines any variations in moth attraction as well as any other sex-based behavioural differences (mating behaviour – wing fanning, trajectory-circular movement, overall movement time) between male and female moths in the presence of warm-white light. This study used warm-white light LED (2718 K) and Galleria mellonella moth, reared in the lab and completed the experiment under standardised conditions in an enclosed setting. I found the male moths (100%) were significantly (p = 0.024) attracted to warm-white light LED compare to female moths (37%). While other behaviours such as wing fanning, circular movement, overall moving time, and favoured light illuminance for rest weren't significantly different (p > 0.05). In the future, it will be important to investigate the effects of warm-white light LED with different lower CCT (< 2718K) on moths, as well as the sex differences in their behaviour both in a controlled and an open environment. This will help authorities to decide on outdoor lighting systems in different countries and continents.
25
Singh, Prasoon. "Investigation of sex-based differences in responses to artificial light of the greater waxmoth (Galleria mellonella)." Thesis, Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-45257.
Full textAbstract:
Artificial light at night (ALAN) is becoming a greater threat to nocturnal species. Aside from the overall increase in light output, replacing outdated monochromatic street lighting with light-emitting diode (LED) lights with a broad emission spectrum could raise this issue more. However, studies evaluating the effect of artificial lights on nocturnal species, such as moths, are scarce. This study examines any variations in moth attraction as well as any other sex-based behavioural differences (mating behaviour – wing fanning, trajectory-circular movement, overall movement time) between male and female moths in the presence of warm-white light. This study used warm-white light LED (2718 K) and Galleria mellonella moth, reared in the lab and completed the experiment under standardised conditions in an enclosed setting. I found the male moths (100%) were significantly (p = 0.024) attracted to warm-white light LED compare to female moths (37%). While other behaviours such as wing fanning, circular movement, overall moving time, and favoured light illuminance for rest weren't significantly different (p > 0.05). In the future, it will be important to investigate the effects of warm-white light LED with different lower CCT (< 2718K) on moths, as well as the sex differences in their behaviour both in a controlled and an open environment. This will help authorities to decide on outdoor lighting systems in different countries and continents.
26
Rittger, Lena [Verfasser], Andrea [Gutachter] Kiesel, and Wilfried [Gutachter] Kunde. "Driving Behaviour and Driver Assistance at Traffic Light Intersections / Lena Rittger. Gutachter: Andrea Kiesel ; Wilfried Kunde." Würzburg : Universität Würzburg, 2015. http://d-nb.info/1111636737/34.
Full text
27
Wong, Chi-wing Andy. "A study of road traffic accidents in relation to public light bus driving behaviour in Hong Kong." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36628761.
Full text
28
Wong, Chi-wing Andy, and 黃志榮. "A study of road traffic accidents in relation to public light bus driving behaviour in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36628761.
Full text
29
Cha, Seunghyun. "Stochastic space-use prediction in light of spatial choice behaviour : modelling space preference of work-related activities." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709375.
Full text
30
Benouaich, Abigail. "Bring Light to Gaza. An exploration of solar and ecologically-sensitive light programs for the Deir al-Balah refugee camp." Thesis, KTH, Ljusdesign, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280044.
Full textAbstract:
In Gaza, daily blackouts have lasted for over eleven years. Until recently, Palestinian families have received only four hours of power each day. Since Israel’s withdrawal from the region in 2005, the political discourse around the Right of Return has forced refugees to live in terrible conditions and darkness. The fear was that any transformation of the camps will bring about an integration of the refugee community with the local environment and thus any improvements to Gaza’s infrastructure and housing was seen as a direct erosion of the Right of Return. Can bringing light to Gaza transcend this boundary of temporality and restore hope to this impoverished community? With recent solar lighting ideas emerging to help solve Gaza’s energy shortage by solar energy companies such as SunBox and LittleSun, I plan to develop a solar urban lighting project for Gaza’s smallest refugee camp - Deir al-Balah (DEB) - to help improve security at night for residents and provide the community with opportunities to socialise in public common areas. In response to an ‘Improvement Plan’ conducted by the United Nations Relief and Works Agency (UNRWA) in 2017, which identifies DEB camp’s limited access to electricity and street lighting, I’d like to explore how a solar and ecologically-sensitive lighting programs can improve Gazan’s daily lives, by bringing clean, reliable and affordable energy access.
31
Brown, Kenneth. "An examination of some factors in motivating religious behaviour in the light of Maslow's analysis of human psychological needs." Thesis, Keele University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250425.
Full text
32
Ebel, Marc. "Digital music consumption on the Internet : consumer behaviour in the light of digital piracy, legal alternatives and ethical considerations." Thesis, University of South Wales, 2014. https://pure.southwales.ac.uk/en/studentthesis/digital-music-consumption-on-the-internet(a351c4f6-b984-4383-8e41-4b9a3c2c988a).html.
Full textAbstract:
Purpose: The purpose of this research is to evaluate the usage behaviour of legal and illegal digital music services on the internet and derive a theoretical model that includes the determinants for these behaviours. Based on this model, hidden heterogeneity will be examined amongst the sample population to extract different user-groups with similar attitudes, perceptions and behaviours and to derive and describe these different customer segments of digital music consumers. Design/methodology/approach: A theoretical framework has been developed through a synthesis of the Theory of Planned Behaviour (TPB), Unified Theory of Usage and Acceptance of Technology (UTAUT) and ethical decision making theories. A structured self- completion online-questionnaire has been conducted in Germany and Partial Least Square Structural Equation Modelling (PLS-SEM) has been applied to analyse and validate the theoretical model. Hidden heterogeneity has been analysed using the Finite Mixture (FIMIX) algorithm for PLS-SEM to derive three different customer segments amongst the sample population. Findings: The cause-and-effect model has been proven valid and has revealed the most important antecedents of the usage of legal vs. illegal digital music services on the internet: performance expectancy, facilitating conditions, habit and usage behaviour, perceived risks and benefits, and attitudes including moral and ethical considerations. Besides this, three different segments of customers have been identified, which show different values, opinions and behaviours with the other segments, but homogeneous within the segments. The segments are: Legal Power-Users, Digital Laggards and Young Indifferents. Practical implications: The cause-and-effect model and the three customer segments inform practice for a better understanding of the digital music customer and provide important inputs for the development of new products and services, positioning of the services and communication strategies for current and future services as well as policy makers. Originality/value: Two research gaps have been closed: (1) newer legal digital music services have hardly been examined in the literature and (2) only student samples have been used in digital piracy studies. This study is the first to fill both gaps in expanding the scope explicitly to legal vs. illegal services and to a sample population beyond students. The synthesis of theoretical models to a more comprehensive model to understand the usage and determinants of digital music services has been created. The identification of the three customer segments with the FIMIX algorithm and their real-life description is a contribution to practice, knowledge and methodology. Additionally the research shows, that the evaluation of hidden heterogeneity enriches the pure SEM-analysis, has even improved the evaluation of the overall model and should be a new standard for future SEM-research.
33
McGeachie, William J. "The effects of air temperature, wind vectors and nocturnal illumination on the behaviour of moths at mercury-vapour light-traps." Thesis, Cranfield University, 1987. http://dspace.lib.cranfield.ac.uk/handle/1826/11424.
Full textAbstract:
Field experiments, with 125 watt Mercury-Vapour light-traps, are described in this Thesis. Catches of moths in water traps arranged in a circular mosaic pattern around the light-trap were distributed bivariate normal. Comparisons between the bivariate mean moth vector and the mean wind vector suggested that the wind vector determined the distribution of moths around the light-trap. In light winds, less than 1 metre/second, moths were randomly distributed around the trap. In stronger winds the direction of moth displacement from the trap was associated with the direction component of the mean wind velocity. A second experiment with light and water traps was used to estimate the effective light-trap radius. Two light-traps, surrounded by water traps, were separated by up to 25 metres on different evenings. When one light-trap was downwind of another the catch was significantly greater in the downwind trap. However, in crosswind conditions the two catches were similar. Bivariate methods were used to estimate that the effective trap radius was between 10 and 25 metres. A further experiment, using multivariate correlation and regression analysis, found that air temperature, windspeed and moonlight affected light-trap catches. An algorithm is described to enable the calculation of moonlight illuminance. Increased windspeed and increased moonlight illuminance tended to decrease the light-trap catch, however, increased air temperature was associated with an increase in light-trap catch. These effects varied depending on family and species. A final experiment used a remote sensing technique to estimate light-trap efficiency. A 10 cubic metre volume around the light-trap was observed using a video camera. Moth tracks recorded were classified into New Arrivals, Passers By and Local Flights. The number of these tracks was compared to the lighttrap catch so that efficiency estimates could be obtained. Results suggested that at ground level, 125 watt Mercury-Vapour light-traps are only 20 % efficient within this 10 cubic metre volume.
34
Coop, Simon. "Nonlinear behaviour of ultracold atoms in optical dipole traps : large atomic light shifts, a quantum phase transition, and interaction-dependent dynamics." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/663161.
Full textAbstract:
This thesis reports on theory and results from two experiments related to nonlinear behaviour in ensembles of optically-trapped ultracold atoms.
The first experiment, performed at ICFO in Barcelona, regards the prediction and measurement of strong ac Stark shifts (light shifts). We present a numerical method based on Floquet's theorem for calculating light shifts to all orders with fewer approximations than the usual calculation based on second-order perturbation theory. The method is experimentally validated by performing absorption spectroscopy of a optically-trapped cloud of cold 87Rb atoms in three scenarios.
1) The atoms are trapped in a singly-polarised monochromatic dipole trap with a wavelength detuned aprox 30nm from the nearest atomic transition. 2) A bichromatic two-polarisation trap, where one wavelength is much closer to atomic transitions (aprox 0:01nm detuning), and finally 3) Another monochromatic trap but with the wavelength variable and scanned close to atomic transitions, again with
aprox 0:01nm detuning but three times the intensity of the near-resonant light in the previous experiment, producing nonlinear light shifts of the D2 transition upto aprox 1 GHz. We discuss the potential application of the method to the accuratemeasurement of electric dipole transition matrix elements. The method is extendedto calculate atomic energy level shifts in the presence of light and staticmagnetic fields.
The second experiment was performed at LENS in Florence, and involves 39K atoms with tunable interactions cooled into the ground- and first-excited state of a two-mode optical potential. We derive a diferential equation to describe behaviour of a two-mode quantum system with tunable interactions, and then solve it to model behaviour of the system in the three distinct regimes of attractive, zero, and repulsive interatomic interactions. With attractive interactions the system is shown to exhibit a quantum phase transition, and with repulsive interactions is shown to exhibit nonlinear dynamics, including behaviour analogous to a superconducting Josephson junction.
As background material the thesis presents a summary of standard laser cooling and trapping echniques, namely Doppler cooling, o+ o- polarisation gradient cooling, magneto-optical trapping, and optical trapping. Optical traps are discussed in detail. We discuss relevant basic physics, derive and analyse a technique for using light shifts to characterise an optical trap, discuss optical Bose-Einstein condensation and control of light intensity to reduce noise-induced heating. Also described is a theoretical proposal for optical evaporation with a constant-depth trap.Esta tesis describe la investigación teórica y los resultados de dos experimentos relacionados con el comportamiento no lineal en un conjuntos de áatomos ultrafríos atrapados ópticamente. En el primer experimento, realizado en ICFO en Barcelona, se presenta la predicción y unos resultados de fuertes cambios de ac Stark (light shifts). Se explica un método numérico basado en el teorema de Floquet para calcular light shifts a todos órdenes con menos aproximaciones que el método habitualmente usado basado en teoría de perturbaciones de segundo orden. El método se valida experimentalmente mediante la realización de espectroscopía de absorción en una nube de átomos de 87Rb ópticamente atrapados en tres escenarios distintos. En el primero, los átomos están atrapados en una trampa de dipolo monocromática de polarización única con una longitud de onda desintonizada 30nm a la transición atómica más cercana. En el segundo se emplea una trampa bicromática de dos polarizaciones, donde una longitud de onda está mucho más cerca de las transiciones atámicas (0.01nm fuera de resonancia). En el tercer y ultimo escenario, se usa una trampa monocromática con la longitud de onda variable y escaneado cerca de transiciones atómicas, nuevamente con 0.01nm desintonizada pero tres veces más intensa que la luz casi resonante del experimento anterior, produciendo light shifts no lineales de la transición D2 hasta 1 GHz. Se discute la aplicabilidad del método para la medición precisa de los elementos de la matriz de transición dipolar eléctrica. Por último, el método se extiende permitiendo calcular los cambios de niveles de energía atómica en presencia de luz y campos magnéticos estáticos. El segundo experimento que se describe en esta tesis se realizó en LENS, en Florencia, e involucra átomos de 39K con interacciones sintonizables en átomos fríos ocupando al estado fundamental y el primer estado excitado de un potencial óptico de dos modos. Se deriva una ecuación diferencial para describir el comportamiento de un sistema cuántico de dos modos con nteracciones sintonizables. Esta se resuelve para modelar el comportamiento del sistema en tres regímenes distintos de interacciones inter-atómicas: atractivas, nulas y repulsivas. En el caso de interacciones atractivas se muestra que el sistema exhibe una transición de fase cuántica. En presencia de interacciones repulsivas el sistema muestra dinámica no lineal, incluyendo un comportamiento análogo a una unión superconductora de Josephson. Como material de referencia, la tesis presenta un resumen de las técnicas estándar de enfriamiento y atrapamiento láser, concretamente enfriamiento Doppler, enfriamiento por gradiente de polarización, atrapamiento magneto-óptico y atrapamiento óptico. Las trampas ópticas se revisan en detalle. Discutimos la física básica relevante, derivamos y analizamos una técnica para usar los light shift para caracterizar una trampa óptica. Analizamos la condensación óptica de Bose-Einstein y el control de la intensidad de la luz para reducir el calentamiento inducido por el ruido. También se presenta una propuesta teórica para la evaporación óptica con una trampa de profundidad constante.
35
Matera, Joana Leonie [Verfasser], and Till [Akademischer Betreuer] Roenneberg. "Chronobiology meets work life : chronotype-dependent nap behaviour and light exposure on work- and free days / Joana Leonie Matera. Betreuer: Till Roenneberg." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2015. http://d-nb.info/1079477489/34.
Full text
36
Krebs, Sabrina. "Whom do we trust? : People’s Voting Behaviour and Trust in Western European Countries under the light of the Crisis of Democracy Discourse." Thesis, Linköping University, Department of Management and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-14904.
Full textAbstract:
The debate about a possible crisis of democracy has been present over 30 years. Questionable is what researchers mean when talking about a potential crisis. What are the factors that are causing it? Are we in a crisis of democracy in Western European countries?The goal of this thesis is to evaluate how different authors characterize what some call a crisis of democracy, to define core topics and to test one of these on empirical data. This will be achieved by firstly, analyzing pieces of literature related to the scientific crisis of democracy debate. Secondly, using Hirschmann’s theory of exit and voice, mass data from will be categorized and analyzed under the light of participation and trust in political institutions.Issues that return are overload on government, individualism, participation and a new culture versus old structure. Analyzing people’s trust in political institutions depending on their intention to go to national elections shows trends: people lose trust in the institutions government, parliament and political parties. Separating the data into groups of potential voters, non-voters and blank voters shows that the latter two show a greater mistrust in political institutions and less interest in politics.Overall, the debate on a potential crisis of democracy is multifaceted and varies between different authors. People are less active in traditional ways of participating, but that does not mean that Western European democracies stand before collapse. It could however mean that new forms of participation are needed to engage people in politics again.
37
Puvanendran, Velmurugu. "Effect of prey concentration and light on the foraging behaviour, growth and survival of Atlantic cod larvae (Gadus morhua) under laboratory conditions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ42484.pdf.
Full text
38
Londei, Marina. "Motori di Rendering a confronto in Blender: Teoria e Applicazioni." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9516/.
Full textAbstract:
L'elaborato prende in esame alcuni motori di rendering, studiandone e descrivendone le caratteristiche sia dal punto di vista teorico-matematico che pratico, con un'ampia introduzione sulla teoria del rendering e sui diversi modelli di illuminazione.
39
Karim, Ali Abdul Jabbar, Johan Lessner, and Mehrdad Moridnejad. "Model calibration of a wooden building block." Thesis, Linnéuniversitetet, Institutionen för bygg- och energiteknik (BE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-26271.
Full textAbstract:
Constructing multi floor buildings by light weight material have increased recently. There are many advantages of using light weight material, such as wood, for the environment. However, one of the deficiencies of lightweight material is the acoustic performance. Transmission of sound and vibration through floors in multi floor buildings in wood is a drawback to be considered. There are many studies that have addressed this issue. It is most common to make a finite element models well as experiments in laboratory. In these studies the material properties in the FE model are probably often adjusted to correlate to the laboratory experiments, since there is a large spread in material properties found in literature. This thesis however tries to elaborate on the actual material properties of the included wooden elements. Dynamic testing is done to determine the spread (here spread means gap between material properties) in material properties of wooden elements. The materials tested are chipboards and two types of wooden beams. The examined beams are both normal wooden beams and laminated veneer lumber beams. When the dynamic behaviour is known for the wooden parts, they are assembled to two small floor systems. The floor systems consist of four beams and one wooden board. The assembly is dynamically tested in laboratory and in FE software. The FE model used the known material properties for each individual building part. The results from the FE model correlate well with the laboratory tests. This shows that when material properties are known a FE model can predict the real behaviour. However, the examined material properties show a large spread from beam to beam, etc and a better knowledge about the material properties of used wooden parts is needed.Att bygga flervåningshus med lätta byggmaterial har blivit allt vanligare. Det finns många fördelar med att använda lätta material, såsom trä. En av fördelarna är att det är skonsamt för miljön. Emellertid är en av bristerna i lättviktsmaterial den akustiska prestandan. Överföring av ljud och vibrationer genom golv i flervåningshus i trä är en nackdel att överväga. Det finns flera studier som har behandlat denna fråga. Ofta görs finita element modeller samt tester i laboratorium. I dessa studier justerar man materialegenskaperna i FE-modellen för att korrelera mot laboratorieexperiment. Detta eftersom det finns en stor spridning i materialegenskaperna för trä i litteraturen. Med detta examensarbete, undersöks de faktiska materialegenskaperna hos träelementen genom försök. Dynamiska tester utförs för att bestämma spridningen i materialegenskaper. De testade materialen är spånskivor och två typer av träbalkar. De undersökta balkarna är både normala träreglar och laminerade faner balkar. När det dynamiska beteendet är känt för trädelarna, monteras de ihop till två små golvsystem. Golvsystemen består av fyra balkar och en träskiva. Den assemblerade modellen testas både dynamiskt i ett praktiskt försök och i ett FE program. I FEmodellen används de tidigare framtagna faktiska materialegenskaper för varje ingående enskild byggnadsdel. Resultaten från FE-modellen korrelerar väl med de praktiska experimenten. Med detta examensarbete visas att när materialegenskaperna är kända kan FE-modellen förutsäga det verkliga beteendet. De undersökta materialegenskaperna visar dock en stor spridning från balk till balk, etc. och mer kunskap om materialegenskaper hos trädelar behövs.
40
Lawson, Siobhan. "Can real time data be used as an effective input for lighting control to influence human behaviour in a physical space against the backdrop of the global shift toward an experience economy?" Thesis, KTH, Ljusdesign, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297947.
Full textAbstract:
The use of real time data as an input for lighting control is an emerging element for designers to implement into lighting schemes but does it add any value or have the ability to influence human behaviour? The recent development in technological capabilities, the demand within the emerging experience economy and the hybridisation of digital and physical realms make this a current and relevant investigation. This study aims to understand the relationship between light and behaviour and the potential of real time data to enhance it by initiating and curating lighting effect in a physical space. In this context, the experience economy describes the business model of providing meaningful and memorable experiences to customers as a core feature of a product or service while real time data describes the harvesting of information as it happens. Through reviewing literature and interviewing professionals in the field of both light and data the results conclude that light does influence behaviour in the context of attention, movement and emotion. Analysis of case studies and technological enablers indicate in-space sensors to be a valuable source of data which can be used effectively to trigger light scenes that respond instantly, with relevance to occupants inhabiting the built environment. Trend reports and industry luminaries forecast strong predictions for the merging of physical and digital worlds as a means of providing memorable and meaningful experiences for retail consumers. It is recommended that lighting designers educate themselves in preparation for the inevitable growing demand for such experiences.
41
Forsyth, Lise Wilma. "'Above everything else, he was a wee boy who wanted to be claimed' : a grounded theory based exploration of Scottish female foster carers' experience of difficult to manage behaviour in light of their attachment characteristics." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/31003.
Full textAbstract:
Background: The role of foster carer is a complex and emotionally demanding one. This is particularly true in the presence of difficult behaviour which can, at times, leave the foster carer feeling overwhelmed and increases the risk of placement breaking down. It is therefore important to find ways to support foster carers. The present study sought to explore the lived experience of foster carers caring for children who presented with difficult to manage behaviour, with consideration given to their attachment characteristics. Aim: The primary aim of this study was to generate a grounded theory of foster carers’ experience of caring for a child who presents with difficult to manage behaviour, in order to inform supports. Method: The study adopted a qualitatively driven mixed methods design (QUAL+quan). Grounded theory (Glaser & Strauss, 1967) was used as the primary component. Eight female foster carers, with either past or present experience of caring for a child who they felt presented them with difficult to manage behaviour, were interviewed. Interviews were recorded and transcribed. Adult attachment data was gathered to elaborate and enhance the interpretation of the foster carers’ narratives. Foster carer’s attachment characteristics were measured using The Relationship Scales Questionnaire (RSQ: Griffin & Bartholomew, 1994), and the presence of behavioural difficulties were confirmed using the Assessment Checklist for Children (ACC: Tarren-Sweeney, 2007). Results: A core category emerged from the grounded theory analysis (‘Making Sense’) in addition to five main categories (‘Personal Impact’, ‘What Helps’, ‘What Makes it Difficult’, ‘Responding’ and ‘The Relationship’). The overarching theme to emerge from the research was the influence foster carer’s level of reflection and understanding of the behaviour (their mentalizing capacity) had on their experience of the child’s difficult behaviour, which appeared to relate to their attachment characteristics in addition to a number of internal and external factors. Consideration is given to the psychological process that emerged from the categories generated from the foster carers’ narratives, and the consequent proposed ground theory. Conclusions: The findings confirm the complexity of the foster caring role, and suggest the positive impact foster carer’s reflective stance can have on their experience of difficult behaviour in the child they care for. Research strengths and limitations are discussed, in addition to clinical practice and research implications.
42
Pozo, Cano Ana del. "Influencia de la luz y los patrones de alimentación sobre el reloj molecular, fisiología digestiva y comportamiento de dos peces teleósteos : lubina (Dicentrarchus labrax) y pez cebra (Danio rerio)= Influence of light and feeding patterns on the molecular clock, digestive physiology and behaviour of two teleost fishes: seabass (Dicentrarchus labrax) and zebrafish (Danio rerio)." Doctoral thesis, Universidad de Murcia, 2013. http://hdl.handle.net/10803/117684.
Full textAbstract:
Tesis por compendio de publicacionesLa luz y los patrones de alimentación influyeron sobre el comportamiento, fisiología y reloj molecular de dos peces teleósteos. Se clonaron dos criptocromos de lubina (cry1 y cry2), expresándose en todos los tejidos estudiados y mostrando ritmos diarios de expresión en cerebro, hígado y corazón (excepto cry2). La fase (día/noche) de alimentación a demanda en lubina afecta a los patrones diarios de actividad amilasa intestinal y expresión de period1 en tejidos periféricos (i.e. hígado), pero no en cerebro. Durante las inversiones estacionales de alimentación de la lubina, mostraron mayores valores de glucosa sanguínea durante la fase de alimentación, revelando también los mayores valores medios en lubinas nocturnas invierno. El pez cebra utilizó un nuevo comedero a demanda, mostrando independencia de fase entre ritmos circadianos de alimentación (nocturno) y locomoción (diurno), con diferentes periodicidades. Además la actividad y posición del pez cebra resultó espectro-dependiente, provocando mayores efectos las longitudes de onda cortas.
Thesis summary in English Light and feeding patterns influence on the behaviour, physiology and molecular clock of two teleost fish. Two cryptochromes (cry1 and cry2) were cloned, being expressed in all studied tissues and showing daily rhythm of expression in brain, liver and heart (except cry2). The self-seabass feeding phase (day/night) affected on daily patterns of intestinal amylase activity and on the period1 expression in peripheral tissues (i.e. liver), but not in brain. During the seasonal feeding inversions in seabass, the highest blood glucose levels were shown during their feeding phase, revealing also the highest values in nocturnal seabass in winter. Zebrafish used a new self-feeding system, displaying phase-independence between feeding (nocturnal) and locomotor (diurnal) circadian rhythms, with different periodicities. Moreover, the zebrafish activity and vertical position were spectrum-dependent, being the main effects provoked by short-wavelengths.
43
Gonçalves, Ana Sofia Ribeiro. "Validação do modelo de ansiedade Light / Dark Exploration Test em ratos Wistar." Master's thesis, Instituto Superior de Psicologia Aplicada, 2007. http://hdl.handle.net/10400.12/558.
Full textAbstract:
Dissertação de Mestrado em EtologiaOs modelos elevated plus-maze e light/dark são amplamente utilizados no estudo de compostos ansiolíticos e dos mecanismos neurobiológicos de ansiedade. O elevated plus-maze (EPM) e o open-field (OF) são testes validados para avaliação da ansiedade em ratos e ratinhos. O teste ligh/dark (LD) também é utilizado nos modelos de ansiedade, no entanto, só foi validado para modelos em ratinhos. Para validar o teste LD como um modelo de ansiedade em ratos avaliaram-se os parâmetros: validade construtiva, validade exterior e validade preditiva. Estes parâmetros foram analisados através de avaliações comportamentais. neuroquímicas e hormonais na presença e ausência de compostos ansiolíticos, e de uma análise comparativa destas avaliações nos testes EPM e LD. Foi ainda estabelecida uma análise comparativa dos dados comportamentais entre o teste OF e os testes EPM e LD. Cada rato (estirpe Wistar) (200-220g) foi colocado no centro do aparelho OF e deixado a explorá-lo durante 20 minutos. Os primeiros 5 minutos foram utilizados para avaliar os comportamentos de ansiedade e os últimos 15 minutos para avaliar a actividade locomotora. Uma semana depois cada rato foi colocado no aparelho EPM (n=6) ou no aparelho LD (n=6) durante 5 minutos. Foram ainda submetidos a estes testes, na mesma ordem, indivíduos tratados com diazepam (0,5mg/kg) (n=6 para cada teste) e propranolol (10mg/kg) (n=6 para cada teste) numa solução de soro fisiológico de 2ml/kg e indivíduos tratados com soro fisiológico (n=6 para cada teste). As sessões experimentais foram registadas por uma câmara de vídeo colocada um metro acima do aparelho e as medidas comportamentais foram registadas e analisadas utilizando o software Noldus Observer. Imediatamente após cada sessão de EPM ou LD os animais foram sacrificados, tendo-se recolhido sangue para doseamento hormonal e dissecado a amígdala e o hipocampo para posterior análise neuroquímica. As concentrações de dopamina (DA), serotonina (5-HT) e dos seus metabolitos foram quantificadas por cromatografia líquida de alta performance combinada com detecção electroquímica. Os níveis de corticosterona no plasma foram medidos por ensaio imunoenzimático. Os resultados comportamentais mostram que os testes EPM e LD induzem respostas comportamentais semelhantes sugerindo que os comportamentos registados nos testes reflectem o mesmo estado psicológico - ansiedade. Esta generalização das respostas comportamentais em diferentes modelos de ansiedade contribui para uma possível validade construtiva do modelo LD para ratos. No entanto, este parâmetro de validade é comprometido pelos resultados neuroquímicos destes animais uma vez que não revelam alterações nas concentrações das monoaminas nas áreas cerebrais analisadas. Por outro lado, a semelhança dos resultados neuroquímicos nos testes LD e EPM indica que estes testes são muito influenciáveis pelas condições e procedimentos usados, uma ideia reforçada pelo aumento dos níveis de serotonina no hipocampo dos indivíduos injectados com soro. Estes resultados evidenciam a importância e a necessidade de uniformizar protocolos e de controlar cautelosamente os procedimentos em todas a etapas da experiência, para possibilitar a utilização destes modelos como indutores de ansiedade. O diazepam e o propranolol não causaram efeitos ansiolíticos nas respostas comportamentais, no entanto, não podemos esquecer que as doses aplicadas são inferiores às utilizadas noutros estudos que mostraram efeitos ansiolíticos. Por outro lado, os dados relativos aos efeitos dos agentes ansiolíticos mostram que os fármacos têm efeitos opostos no rato, tanto no EPM como no LD. Além disso, esse efeito reflecte-se a nível comportamental e neuroquímico. A nível comportamental o diazepam induziu uma redução do estado de alerta enquanto que o propanolol induziu um aumento do estado de alerta. A nível neuroquímico o diazepam induziu uma diminuição dos níveis de serotonina no hipocampo ao contrário do propranolol que induziu um aumento dos níveis de serotonina na mesma área cerebral. Estes resultados sugerem que o propranolol parece ter um efeito ansiogénico originado pela manipulação dos animais aliada ao bloqueio, pelo propranolol, dos processos de reconsolidação da memória activa, o que eliminou os efeitos de habituação ao stress induzido pela manipulação. Estas alterações neuroquimicas foram observadas apenas nos ratos expostos ao EPM indicando que o EPM e o LD desencadeiam aspectos distintos de ansiedade. Estes resultados comprometem a validade preditiva do modelo mas os procedimentos realizados são insuficientes para concluir acerca deste parâmetro. Nas respostas hormonais produzidas por estes testes não foi verificado um aumento nos níveis de corticosterona após a exposição aos testes de ansiedade, no entanto, estes dados podem ter sido influenciados por aspectos da variação circadiana o que torna difícil inferir sobre o critério de validade exterior. A heterogeneidade das formas patológicas de ansiedade existentes toma difícil que um modelo de ansiedade reúna os 3 critérios de validade, no entanto, este trabalho indica que o modelo LD não é um modelo de ansiedade ideal para ratos. Os resultados deste estudo são mais uma contribuição para a evidência crescente da importância e necessidade de uma análise complexa baseada em observações comportamentais no aperfeiçoamento da credibilidade e sensibilidade destes modelos animais.
44
Angeli, Anastasia. "Public tendencies and perception of brightness and light in Odenplan." Thesis, KTH, Ljusdesign, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297649.
Full textAbstract:
This research paper is discussing light, and brightness in particular, in terms of perception, taking Odenplan as a case study.Some links between light characteristics and behaviour patterns, such as lingering, have been made, raising the discussion about the qualities of the artificial lighting that would add to convivial urban spaces at nighttime, attempting at differentiating between how people think they would behave and how they actually behave in a public square, and the impact of artificial lighting on public tendencies, suggesting if people feel comfortable and safe in the space, then they tend to perceive the space brighter. The research has shown that it is hard to draw conclusions when it comes to perceived qualities of light. Different research methods have been used with the intention of suggesting a methodology to be explored by others, including literature review, empirical study, informal interviews and word association survey.
45
Darcy, Greg. "Structural behaviour of an innovative cold-formed steel building system." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16589/.
Full textAbstract:
Cold-formed steel structures have been in service for many years and are used as shelters for both domestic and industrial purposes. To produce an economical product, manufacturers have typically based their designs on the simple portal frame concept. As there is almost a direct relationship between overall cost and the weight of steel in a portal frame structure, it is of great importance to provide a structure with the minimum amount of steel whilst providing structural adequacy. Portal frame sheds have been refined continuously for many years, with only minimal amounts of savings in steel. Therefore, to provide even greater savings in steel, an innovative building system is required. Modern Garages Australia (MGA) is one of the leading cold-formed steel shed manufacturers in Queensland. MGA has recently developed such an innovative building system that has significant economic savings when compared with portal frame structures. The MGA building system has two key differences to that of the conventional portal frame system. These differences are that the MGA system has no conventional frames or framing system, and it has no purlins or girts. This results in the MGA system being completely fabricated from thin cladding, which significantly reduces the quantity of steel. However, the key problem with this building system is that the load paths and structural behaviour are unknown, and therefore the structure cannot be analysed using conventional methods. Therefore, the objectives of this research were to first investigate the structural behaviour of this new building system and its adequacy for an ultimate design wind speed of 41 m/s using full scale testing. The next objectives were to use finite element analysis to optimise the original MGA building system so that it is adequate for an ultimate design wind speed of 41 m/s, and to develop a new improved cold-formed steel building system that has greater structural efficiency than the original MGA building system. This thesis presents the details of the innovative MGA building system, full scale test setup, testing program, finite element analysis of the MGA building system and the results. Details and results from the optimisation of the MGA building system, and the development of a new improved cold-formed steel building system are also presented. The full scale experimental investigation considered the required loadings of cross wind, longitudinal wind and live load test cases and simulated them on the test structure accurately using an innovative load simulation system. The wind loads were calculated for a 41 m/s ultimate design wind speed. Full scale test program included both non-destructive and destructive tests. The finite element analyses contained in this thesis have considered cross wind, longitudinal wind and live load cases, as well as the destructive load case of the MGA building system. A number of different model types were created and their results were compared with the experimental results. In general, two main model types were created. The first type consisted of a 'strip' of the MGA building system (Strip model) and the second modelled the full structure (Full model). Both of these model types were further divided into models which contained no contact surfaces and those which contained contact surfaces to simulate the interfaces between the various components such as the brackets and cladding. The experimental test results showed that the MGA test structure is not suitable for an ultimate design wind speed of 41 m/s. This conclusion is a result of a number of observed failures that occurred during the extensive testing program. These failures included local buckling, crushing failures, and distortional buckling of the cladding panels. Extremely large deflections were also observed. It was calculated that for the MGA building system to be adequate for the design wind speed of 41 m/s, a cladding thickness of 0.8 mm was required. This also agreed well with the finite element analysis results which concluded that a cladding thickness of 0.8 mm was required. In order to avoid the increased use of steel in the building system, a new improved cold-formed steel building system was developed and its details are provided in this thesis. A finite element model of this new improved cold-formed steel building system was created and the results showed that the new building system was able to achieve a load step equivalent to an ultimate design wind speed of 50.4 m/s and was approximately 250% stiffer than the original MGA building system, without any increase in the overall weight of the building system. It is recommended that this new improved cold-formed steel building system be further developed with the aid of finite element modelling and be tested using a similar full scale testing program that was used for the original MGA building system.
46
Twumasi, Ricardo. "Working late : exploring the new dynamics of later life working in light of changes in age related legislation, policy and practice." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/21765.
Full textAbstract:
Demographic changes have facilitated longer, healthier lives, and legislative changes have encouraged extended working lives through the increasing of state pension age, equalisation of state pensions, and the removal of the default retirement age. Recent age discrimination legislation has begun to combat age discrimination within the employment context of the UK. Legal precedent has also been established during the course of this research through case law, as a result of high profile age discrimination cases reaching the Supreme Court. Through several interview studies, this thesis explores the experiences, views and attitudes of employees, employers, job seekers and retired individuals. Utilising focus groups, this thesis also presents data from a range of charity representatives, human resources professionals, line managers, employment advisors, health and safety practitioners, and trade union representatives in order to explore the influence of changes in later life working policy and practice. The research of this thesis also includes a consultation exercise to engage the potential users of the research and develops a policy and practice framework providing recommendations which could lead to better outcomes and improved opportunities for older workers. Finally, a series of video case studies presents the research findings in an accessible visual format. This varied use of communication methods was specifically selected in order to increase the impact of the research and potential user audience. Research findings highlighted that managing age diversity was perceived as essential for employee motivation and organisational competitiveness. In particular, interviewees from generationally diverse workforces also reported a more positive attitude to age. Evidence from this thesis presents direct examples of age discrimination limiting the employment opportunities of older workers. Potential victims of age discrimination often struggle to gather evidence to support their perception that they may have been mistreated due to their age. Especially for job seekers, the perception of age discrimination presents a significant barrier to confidence, motivation, and opportunities during the employment search. These concerns are also exacerbated by the most widely reported barrier to securing employment for older jobseekers which was insufficient feedback. While a small minority of employers discussed discriminatory practices, the majority were positive towards age diversity and embraced the benefits of older workers. Responsibility for retirement transitions and performance management as older employees reach the end of their careers were issues employers reported struggling with in light of the removal of the default retirement age. The findings of this thesis highlight the importance of challenging age stereotypes and embracing the opportunities that a multi-generational workforce offers in order to increase equality of opportunity and promote age positive organisational culture. All parts of society have a shared responsibility to change attitudes towards older workers, and offer workers of all ages the equality they deserve.
47
Ranawaka, Thanuja. "Distortional buckling behaviour of cold-formed steel compression members at elevated temperatures." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16417/.
Full textAbstract:
In recent times, light gauge cold-formed steel sections have been used extensively in residential, industrial and commercial buildings as primary load bearing structural components. This is because cold-formed steel sections have a very high strength to weight ratio compared with thicker hot-rolled steel sections, and their manufacturing process is simple and cost-effective. However, these members are susceptible to various buckling modes including local and distortional buckling and their ultimate strength behaviour is governed by these buckling modes. Fire safety design of building structures has received greater attention in recent times due to continuing loss of properties and lives during fires. Hence, there is a need to fully evaluate the performance of light gauge cold-formed steel structures under fire conditions. Past fire research has focused heavily on heavier, hot-rolled steel members. The buckling behaviour of light gauge cold-formed steel members under fire conditions is not well understood. The buckling effects associated with thin steels are significant and have to be taken into account in fire safety design. Therefore, a research project based on extensive experimental and numerical studies was undertaken at the Queensland University of Technology to investigate the distortional buckling behaviour of light gauge cold-formed steel compression members under simulated fire conditions. As the first phase of this research program more than 115 tensile coupon tests of light gauge cold-formed steels including two steel grades and five thicknesses were conducted at elevated temperatures. Accurate mechanical properties including the yield strength, elasticity modulus and stress-strain curves were all determined at elevated temperatures since the deterioration of the mechanical properties is one of the major parameters in the structural design under fire conditions. An appropriate stress-strain model was also developed by considering the inelastic characteristics. The results obtained from the tensile coupon tests were then used to predict the ultimate strength of cold-formed steel compression members. In the second phase of this research more than 170 laboratory experiments were undertaken to investigate the distortional buckling behaviour of light gauge coldformed steel compression members at ambient and elevated temperatures. Two types of cross sections were selected with various thicknesses (nominal thicknesses are 0.6, 0.8, and 0.95 mm) and both low and high strength steels (G250 and G550 steels with minimum yield strengths of 250 and 550 MPa). The experiments were conducted at six different temperatures in the range of 20 to 800°C. A finite element model of the tested compression members was then developed and validated with the help of experimental results. The degradation of mechanical properties with increasing temperatures was included in finite element analyses. An extensive series of parametric analyses was undertaken using the validated finite element model to investigate the effect of all the influential parameters such as section geometry, steel thickness and grade, mechanical properties and temperature. The resulting large data base of ultimate loads of compression members subject to distortional buckling was then used to review the adequacy of the current design rules at ambient temperature. The current design rules were reasonably accurate in general, but in order to improve the accuracy further, this research has developed new design equations to determine the ultimate loads of compression members at ambient temperature. The developed equation was then simply modified by including the relevant mechanical properties at elevated temperatures. It was found that this simple modification based on reduced mechanical properties gave reasonable results, but not at higher temperatures. Therefore, they were further modified to obtain a more accurate design equation at elevated temperatures. The accuracy of new design rules was then verified by comparing their predictions with the results obtained from the parametric study. This thesis presents a description of the experimental and numerical studies undertaken in this research and the results including comparison with simply modified current design rules. It describes the laboratory experiments at ambient and elevated temperatures. It also describes the finite element models of cold-formed steel compression members developed in this research that included the appropriate mechanical properties, initial geometric imperfections and residual stresses. Finally, it presents the details of the new design equations proposed for the light gauge coldformed steel compression members subjected to distortional buckling effects at elevated temperatures.
48
Beaugeard, Erika. "Comment faire face à l’urbanisation ? Étude écophysiologique des bénéfices et contraintes d’un mode de vie urbain chez les passereaux." Thesis, La Rochelle, 2020. http://www.theses.fr/2020LAROS010.
Full textAbstract:
L’urbanisation est l’un des phénomènes majeurs qui impactent la biodiversité à l’échelle mondiale. Les nombreuses contraintes associées au milieu urbain (perte d’habitat, changement des ressources, pollutions chimique, lumineuse et sonore, etc.) modifient la diversité et la répartition des espèces animales, et peuvent avoir de lourdes conséquences à l’échelle individuelle. Or, le développement constant du milieu urbain nécessite de mettre à jour les études sur les effets de ce milieu sur les espèces animales, et en particulier sur les oiseaux, qui rendent de nombreux services écosystémiques à l’homme. Dans ce contexte, nous avons cherché à étudier les bénéfices et contraintes du milieu urbain chez les oiseaux, en se plaçant à trois échelles différentes : biodiversité, population et individu. Dans un premier temps, nous avons réalisé une étude spatiale de la biodiversité aviaire à Niort. Nous avons pu mettre en évidence l’importance de maintenir des infrastructures vertes et connectées en ville, pour favoriser la présence des espèces communes comme celles moins adaptées au milieu urbain. Dans un deuxième temps, nous avons cherché à évaluer l’état des populations de moineaux domestiques en ville, ceux-ci étant en fort déclin dans les grandes villes européennes. À l’aide d’une étude corrélative, nous avons démontré que le milieu urbain est particulièrement stressant pour les moineaux en développement. Également, l’analyse d’un stress hydrique en conditions expérimentales nous a permis de constater que les moineaux adultes sont également très sensibles aux changements des conditions de l’environnement. Dans un troisième temps, l’application d’une contrainte du milieu urbain (pollution lumineuse) sur les moineaux au cours de la reproduction a permis de mettre en évidence des changements rapides du comportement individuel en réponse à cette contrainte. Les résultats de ces différentes approches démontrent que les effets de l’urbanisation sur les oiseaux sont complexes, et que les suivis démographiques doivent être associés à des études précises de l’habitat urbain et des contraintes associées pour mieux comprendre l’évolution des populations d’oiseaux en villeUrbanization is one of major phenomena that impact biodiversity in the world. Numerous constraints associated with urban environment (habitat loss, changes in resources, chemical, light and noise pollutions, etc.) modify wildlife diversity and species distribution, and can have detrimental consequences on individuals. However, constant development of urbanization implies to update studies on the effects of urban environment on animal species, and particularly on birds, as they fulfill numerous ecosystem services for humans. In that context, we studied the benefits and costs of urban life for birds, working at three different levels: biodiversity, population and individual. First, we realized a spatial study on avian biodiversity in Niort (France). We highlighted the need to maintain green and connected infrastructures in cities, to favor common species as less adapted species to urban environment. Second, we evaluated the population state of house sparrows in cities, as they are strongly declining in large European cities. With the use of a correlative study, we showed that urban environment is very stressful for developing sparrows. Moreover, the analysis of osmotic stress in experimental conditions allowed to find that adult sparrows are also sensitive to changes of environmental conditions. Third, the application of a constraint of urban environment (light pollution) on house sparrows during reproduction revealed rapid changes in individual behavior in response to this constraint. Finally, results of these different approaches show that the effects of urbanization on birds are complex, and that demographic surveys need to be coupled with precise studies of urban habitat and associated constraints to better understand the evolution of bird populations in cities
49
Heva, Yasintha Bandula. "Behaviour and design of cold-formed steel compression members at elevated termperatures." Queensland University of Technology, 2009. http://eprints.qut.edu.au/29310/.
Full textAbstract:
Cold-formed steel members have been widely used in residential, industrial and commercial buildings as primary load bearing structural elements and non-load bearing structural elements (partitions) due to their advantages such as higher strength to weight ratio over the other structural materials such as hot-rolled steel, timber and concrete. Cold-formed steel members are often made from thin steel sheets and hence they are more susceptible to various buckling modes. Generally short columns are susceptible to local or distortional buckling while long columns to flexural or flexural-torsional buckling. Fire safety design of building structures is an essential requirement as fire events can cause loss of property and lives. Therefore it is essential to understand the fire performance of light gauge cold-formed steel structures under fire conditions. The buckling behaviour of cold-formed steel compression members under fire conditions is not well investigated yet and hence there is a lack of knowledge on the fire performance of cold-formed steel compression members. Current cold-formed steel design standards do not provide adequate design guidelines for the fire design of cold-formed steel compression members. Therefore a research project based on extensive experimental and numerical studies was undertaken at the Queensland University of Technology to investigate the buckling behaviour of light gauge cold-formed steel compression members under simulated fire conditions. As the first phase of this research, a detailed review was undertaken on the mechanical properties of light gauge cold-formed steels at elevated temperatures and the most reliable predictive models for mechanical properties and stress-strain models based on detailed experimental investigations were identified. Their accuracy was verified experimentally by carrying out a series of tensile coupon tests at ambient and elevated temperatures. As the second phase of this research, local buckling behaviour was investigated based on the experimental and numerical investigations at ambient and elevated temperatures. First a series of 91 local buckling tests was carried out at ambient and elevated temperatures on lipped and unlipped channels made of G250-0.95, G550-0.95, G250-1.95 and G450-1.90 cold-formed steels. Suitable finite element models were then developed to simulate the experimental conditions. These models were converted to ideal finite element models to undertake detailed parametric study. Finally all the ultimate load capacity results for local buckling were compared with the available design methods based on AS/NZS 4600, BS 5950 Part 5, Eurocode 3 Part 1.2 and the direct strength method (DSM), and suitable recommendations were made for the fire design of cold-formed steel compression members subject to local buckling. As the third phase of this research, flexural-torsional buckling behaviour was investigated experimentally and numerically. Two series of 39 flexural-torsional buckling tests were undertaken at ambient and elevated temperatures. The first series consisted 2800 mm long columns of G550-0.95, G250-1.95 and G450-1.90 cold-formed steel lipped channel columns while the second series contained 1800 mm long lipped channel columns of the same steel thickness and strength grades. All the experimental tests were simulated using a suitable finite element model, and the same model was used in a detailed parametric study following validation. Based on the comparison of results from the experimental and parametric studies with the available design methods, suitable design recommendations were made. This thesis presents a detailed description of the experimental and numerical studies undertaken on the mechanical properties and the local and flexural-torsional bucking behaviour of cold-formed steel compression member at ambient and elevated temperatures. It also describes the currently available ambient temperature design methods and their accuracy when used for fire design with appropriately reduced mechanical properties at elevated temperatures. Available fire design methods are also included and their accuracy in predicting the ultimate load capacity at elevated temperatures was investigated. This research has shown that the current ambient temperature design methods are capable of predicting the local and flexural-torsional buckling capacities of cold-formed steel compression members at elevated temperatures with the use of reduced mechanical properties. However, the elevated temperature design method in Eurocode 3 Part 1.2 is overly conservative and hence unsuitable, particularly in the case of flexural-torsional buckling at elevated temperatures.
50
Hagos, Bereket Abrha. "Microstructural and chemical behaviour of irradiated graphite waste under repository conditions." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/microstructural-and-chemical-behaviour-of-irradiated-graphite-waste-under-repository-conditions(45b519ef-2f67-4aca-9b92-94a975e12875).html.
Full textAbstract:
A procedure to evaluate the leaching properties of radionuclides from irradiated graphite waste has been developed by combining ANSI 16.1 (USA) and NEN 7345 (Netherlands) standardised diffusion leaching techniques. The ANSI 16.1 standard has been followed to the acquire the leachates and to determine the leach rate/ diffusion coefficient and NEN 7345 standard technique has been used to determine the diffusion mechanism of radionuclides. The investigation employs simulated Drigg groundwater as a leachant using semi-dynamic technique for the production of leachate specimens. From gamma spectroscopy analysis the principal radionuclides present in terms of activity were 60Co, 137Cs, 134Cs, 155Eu, 133Ba and 46Sc. The dominant radionuclides are 60Co, 134Cs and 133Ba which together account for about 91 % of the total activity. The 91 % can be broken down into 73.4 % 60Co, 9.1 % 134Cs and 8.1 % 133Ba. Analysis of total beta and total beta without tritium activity release from Magnox graphite was measured using liquid scintillating counting. Preliminary results show that there is an initial high release of activity and decreases when the leaching period increases. This may be due to the depletion of contaminants which were absorbed by the internal pore networks and the surface. During the leaching test approximately 275.33 ± 18.20 Bq of 3H and 106.26 ± 7.01 Bq of 14C was released into the leachant within 91 days. Irradiation induced damages to the nuclear graphite crystal structure have been shown to cause disruption of the bonding across the basal planes. Moreover, the closures of Mrozowski cracks have been observed in nuclear graphite, the bulk property are governed by the porosity, in particular, at the nanometre scale. Therefore, knowledge of the crystallite structure and porosity distribution is very important; as it will assist in understand the affects of irradiated damage and location and the mechanism of the leaching of radionuclides. The work reported herein contributed several key findings to the international work on graphite leaching to offer guidance leading toward obtaining leaching data in the future: (a) the effective diffusion coefficient for 14C from graphite waste has been determined. The diffusion process for 14C has two stages resulting two different values of diffusion coefficient, i.e., for the fast and slow components; (b) the controlling leaching mechanism for 3H radionuclide from graphite is shown to be surface wash–off; and for that of 14C radionuclide the initial controlling leaching mechanism is surface wash-off following by diffusion which is the major transport mechanism ; (c) The weight loss originates from the open pore structure which has been opened up by radiolytic oxidation; at the higher weight losses much of the closed porosity in the graphite has been opened. The investigation indicates that weigh loss has a major influence on the leaching of elements from the irradiated graphite; and (d) the analysis of the pores in nuclear graphite can be categorised into three types. These three types of pores are: (1) small pores narrow which are slit-shaped pores in the binder phase or matrix, (2) gas evolution pores or gas entrapment pores within the binder phase or matrix and (3) lenticular pores which are large cracks within the filler particles. It is shown in this thesis that by using tomography to study the morphology of the different pores coupled with the distribution of impurities an understanding of the role of porosity in leaching is possible.