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1
Yeung, Shu-pui, e 楊樹培. "Odour mitigation measures for odour reduction in the Kai Tak Nullah". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B3125570X.
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Webb, Paul. "Electronic odour sensing systems". Thesis, University of Warwick, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332850.
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Elliott, Joanne Margaret. "Conducting polymer odour sensors". Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242764.
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4
Sohn, Jae Ho. "Process studies of odour emissions from effluent ponds using machine-based odour measurement". University of Southern Queensland, Faculty of Engineering and Surveying, 2005. http://eprints.usq.edu.au/archive/00001511/.
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Odours caused by intensive piggery operations have become a major environmental issue in the piggery industry in Australia. Effluent ponds are the major source of odours in typical piggeries. It is assumed that the odour emissions from ponds are mainly driven by pond loading rate. However, there are few data to corroborate this concept. Allied to this is the need for a convenient and low cost method of odour measurement, which can be used as an alternative method for current olfactometry. The present odour measurement methods using olfactometry is time-consuming, expensive and often impractical because of its fundamental problem of using subjective human panels. In addition, one of the major problems in odour measurement lies in the air sampling method. Wind tunnels have been accepted as a preferred method for the sampling of odour from area sources. However, current wind tunnels do not consider meteorological factors, which directly affect the odour emission rates. A machine-based odour quantification method and a novel wind tunnel were developed and evaluated in this Ph D study. These methods were then used in a demonstration trial to investigate the effects of pond loading rate on odour emissions. The AromaScan A32S electronic nose, and an artificial neural network were used to develop the machine based odour quantification method. The sensor data analysed by the AromaScan were used to train an ANN, to correlate the responses to the actual odour concentration provided by a human olfactometry panel. Preprocessing techniques and different network architectures were evaluated through network simulation to find an optimal artificial neural network model. The simulation results showed that the two-layer back-propagation neural network can be trained to predict piggery odour concentrations correctly with a low mean squared error. The trained ANN was able to predict the odour concentration of nine unknown air samples with a value for the coefficient of correlation, r2 of 0.59. A novel wind tunnel was developed for odour sampling. The USQ wind tunnel was designed to have a capability to control wind speed and airflow rate. The tunnel was evaluated in terms of the aerodynamics of the airflow inside the tunnel, nd the gas recovery efficiency rate, in order to further improve the performance of the wind tunnel. The USQ wind tunnel showed that sample recovery efficiencies ranging from 61.7 to 106.8%, while the average result from the entire trial was 81.1%. The optimal sample recovery efficiency of the tunnel was observed to be 88.9% from statistical analysis. Consequently, it can be suggested that the tunnel will give estimates of the odour emission rate with significant level of precision. However, the tunnel needs to be calibrated to compensate for the error caused by different airflow rates and odour emission rates. In addition, the installation of a perforated baffle upstream of the sampling section was suggested to improve its performance. To investigate the relationship between the pond loading rate and odour emission rate, replicable experimental studies were conducted using a novel experimental facility and the machine based odour quantification method. The experimental facility consisted of reactor vessels to simulate the operation of effluent ponds and the USQ wind tunnel for odour sampling. A strong relationship between organic loading rate (OLR) and physical and chemical parameters was observed except pH and NH3-N. The pH was not affected by OLR due to the buffering capacity of piggery effluent. EC and COD were suggested as indicators to estimate the operating condition of the piggery effluent ponds because the regression results show that these two parameters can be predicted accurately by OLR. The time averaged odour emission rates from the reactor vessels showed a strong relationship with OLR. Consequently, it can be concluded that heavily loaded effluent ponds would produce more odours. The effect of hydraulic retention time (HRT) was examined. The HRT was increased from 30 days to 60 days, resulting in a significant decrease in odour emission rates from the reactor vessels. This decrease ranged from 59.1% to 54.9%, with an average of 57.1%. Therefore, it can be concluded that the increasing HRT will decrease the odour emission rate. This trial confirmed the value of the project methodology in obtaining unambiguous data on odour emission processes. However, more data are required for a wider range of OLR, HRT and other pertained variables before a usable model can be formulated.
5
Andersson, Johan. "Odour Communication in Pieris Butterflies". Doctoral thesis, KTH, Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3699.
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6
McQueen, Rachel, e n/a. "Axillary odour in apparel textiles". University of Otago. Department of Clothing and Textile Sciences, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070307.120703.
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The axilla is a major source of human body odour from which the characteristic musky, urinous or acidic odours emanate, and are predominantly due to bacterial metabolism of the protein-rich fluid secreted by the apocrine and sebaceous glands located in this area (Senol and Fireman, 1999). Clothing has been implicated in contributing to body odour intensity, possibly even increasing the intensity (Dravnieks, et al., 1968; Shelley, et al., 1953) by the transfer of secretions, skin debris and bacteria from the body to the fabric substrate. Despite much anecdotal evidence indicating that some fibres and fabrics are better at limiting odour intensity than others, there appears to be no published research confirming this. The purpose of this study therefore, was to determine whether fabrics varying in fibre content (cotton, wool, polyester) and fabric knit structure (interlock, single jersey, 1x1 rib) differed in the extent to which they retained and emanated axillary odour following wear, and whether the intensity of odour was linked to the number of bacteria transferred to the fabrics. A procedure for collecting odour on fabrics was developed as was a method for evaluating odour through use of a sensory panel. Total aerobic bacteria and aerobic coryneform bacteria extracted from the fabrics were counted to determine if an association between bacterial counts and fabrics existed. Sensory analysis recognises the unique capability of humans as odour-detecting instruments whereas, instrumental analysis has the potential to offer information on the concentration and identification of axillary compounds, which a human assessor cannot. To investigate a new method for detecting axillary odour on apparel fabrics, proton transfer reaction mass spectrometry (PTR-MS) was used to analyse volatiles emitted from fabrics differing in fibre type.
After removal of garments from the human body, axillary odour can be detected on fabrics, with the intensity of odour being strongly influenced by the fibre type from which the fabrics had been made. Polyester fabrics emanated odour of high intensity, cotton that of mid-low odour intensity, and wool fabrics were low odour. Fabric structural properties such as thickness, mass per unit area and openness of knit structure also had an effect on odour intensity. However, as the principal factor influencing odour intensity was fibre, only fabrics characterised by a high intensity (i.e. polyester) were influenced by structural properties. Differences in odour intensity among fabrics were not necessarily related to bacterial numbers, and no �inherent antimicrobial� properties were evident for any of the fabrics. Bacterial populations persisted in all fabrics up to 28 days. A decline in numbers was apparent for high-odour polyester fabrics, while numbers in low-odour wool fabrics remained relatively stable. PTR-MS detected compounds likely to be short-chain carboxylic acids which increased in the headspace above the polyester fabrics after 7 days. However, this increase was not evident for either the wool or cotton fabrics. Therefore, bacterial numbers per se cannot be a predictor of the odour intensity emanating from fabrics at least on the basis of these fabrics and fibres. The intensity of axillary odour emanating from fabrics was found inversely related to fibre hygroscopicity.
Keywords:fibre content, fabric structure, axillary odour, sensory analysis, bacteria, corynebacteria, instrumental analysis, PTR-MS
7
Qu, Guoliang. "The measurement of odour concentration". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0014/NQ60016.pdf.
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King, Russell. "Odour responses and discrimination strategies". Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313895.
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Huotari, M. (Matti). "Odour sensing by insect olfactory receptor neurons: measurements of odours based on action potential analysis". Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514275918.
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Abstract
This thesis is a study of the odour responses of insect olfactory (or odorant) receptor neurons (ORN) of blowfly (Calliphora vicina), mosquito (Aedes communis), fruitflies (Drosophila melanogaster and D. virilis) and large pine weevil (Hylobius abietis). A power-law dependence (similar to Stevens' law in psychophysics) was obtained for the action potential rate of ORN responses vs. odour concentration in measurements with metal microelectrodes from blowfly ORNs and an analysis system was developed for the extracellularily recorded action potentials (or nerve pulses).
Odour exposure sequences were used to study action potential rates quantitatively as a function of odour concentration in air exposure. For an odour exposure sequence, a known initial amount of the odour compound in a filter paper inside a Pasteur pipette at the beginning of repeated exposures caused a gradual dilution of the odour concentration in the exposure sequence. The concentration at each exposure was calculated according to the discrete multiple headspace extraction and dilution (DMHED) method. The estimated odour concentration was assumed to obey in the method an exponential law with respect to the exposure number in the sequence. Despite that many uncontrollable parameters remain for measuring quantitatively the characteristics of the ORNs, the results obtained, e.g., sensitivity, specificity, adaptability, and the power-law realation are both biologically and technically very interesting.
A time-to-voltage converter (TVC) was utilized for the response analysis in determining action potential intervals originating from a single ORN. A precision analysis of TVC was also performed.
With the mosquito (Aedes communis), fruitflies (Drosophila melanogaster and D. virilis) and large pine weevil (Hylobius abietis) antennae were tested for inhibitory and excitatory effects to find out repellents and attractants. Human sweat was found to cause strong stimulus exposure in the responses of the mosquito ORNs and Neutroil® caused inhibitory responses in pine weevil ORNs, respectively.
The power-law exponents for blowfly ORNs were about 0.19 in the case of 1-hexanol (HX), 0.065 in the case of 1,4-diaminobutane (14DAB) and 0.32 in the case of butyric acid (BA). The corresponding Stevens' law exponent values 0.39 and 0.33 have been reported for HX and BA, respectively, by Patte et al. (1975).
10
Ma, Yue 1971. "Software development for odour impact assessment". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80128.
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Odour impacts are the source of many complaints in communities and, as such, methods for odour impact assessment are needed. Such assessments would benefit from the development of parameters that could be used to quantify and reflect the magnitudes of odour impacts experience by the community. Therefore, numerous parameters that can be used to assess odour impacts have been proposed in this research. These parameters account for variations in odour concentration, probability of response, degree of annoyance and population density that clearly influence the degree of impact of an odorous emission on a community. Most of these parameters require the evaluation of areas enclosed within contours and volumes under contours and, as such, are calculation intensive. In order to simplify the calculation of these parameters, algorithms have been developed and implemented into a user-friendly interface called OdorImp. This software was tested by applying it to three sets of synthetic data and two sets of data arising from actual case-studies. Comparisons were made between the results from OdorImp and exact values derived from simple cases and other values calculated using a commercial contour-evaluation program. It was demonstrated that the algorithms implemented in OdorImp are accurate and can be used to reliably evaluate the proposed odour impact parameters.
11
Leiferkus, Jan. "Disease diagnosis based on odour detection". Thesis, Cranfield University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274049.
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Nimmermark, Sven. "Odour impact : odour release, dispersion and influence on human well-being with specific focus on animal production /". Alnarp : Dept. of Agricultural Biosystems and Technology (JBT), Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a494.pdf.
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Montreer, Pascale. "Identification des molécules responsables de l'odeur d'un mélange gazeux – Vers une automatisation de la démarche". Thesis, IMT Mines Alès, 2019. http://www.theses.fr/2019EMAL0007.
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Dans le milieu industriel, les matériaux générant une odeur désagréable représentent une problématique majeure.En effet, l’odeur fait très souvent partie des critères de sélection, d’achat et d’utilisation d’un produit par le consommateur. Si un matériau a une odeur désagréable, il risque d’être rejeté par le consommateur qui considérera sa qualité comme mauvaise ou altérée.Améliorer la qualité odorante d’un matériau constitue donc un enjeu industriel et économique important.Dans ce contexte, le travail réalisé dans le cadre de cette thèse consiste à développer un protocole permettant d’identifier le ou les composés chimiques responsables de l’odeur désagréable d’un matériau. Ce protocole est développé sous forme d’un outil automatisé combinant une succession de techniques statistiques.L’un des piliers de ce travail est la recherche de corrélations entre la composition de la matrice gazeuse émise par le matériau (mesures physico-chimiques) et l’odeur associée à cette matrice (mesures olfactométriques). Pour atteindre cet objectif, un important travail d'investigation sur les seuils de perception olfactive (fiabilité et complétude des données) a été réaliséIn the industrial environment, materials generating an unpleasant smell are a major problem.Indeed, the smell is often part of the criteria for the selection, purchase and use of a product by the consumer. If a material has an unpleasant smell, it may be rejected by the consumer who will consider its quality as bad or distorted.Improving the odorant quality of a material is therefore an important industrial and economic challenge.In this context, the thesis project consists in developing an analytical protocol to identify the chemical compounds responsible for the unpleasant odor of a material. This analytical protocol is developed as an automated tool combining a succession of statistical techniques.One of the pillars of this work is the search for correlations between the composition of the gaseous matrix emitted by the material (physico-chemical measurements) and the odour associated with this matrix (olfactometric measurements). To achieve this objective, an important investigation work on odour detection thresholds (reliability and completeness of data) was carried out
14
Jinks, Anthony L., of Western Sydney Hawkesbury University, Faculty of Science and Technology e School of Food Science. "The Perception of complex odour mixtures by humans". THESIS_FST_SFS_Jinks_A.xml, 1999. http://handle.uws.edu.au:8081/1959.7/313.
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In two parts, this thesis examined the perception of odour mixtures by humans. Several experiments were carried out and results shown. Part 1 established that peripheral interaction in the form of competition for transduction pathway resources is not of primary importance in determining the perceptual characteristics of odour mixtures. Other peripheral mechanisms, central factors and limitations in human cognitive processing would also appear to play an important role.Taking into account the temporal processing results found in Part 1, Part 2 sought to establish the capacity of humans to analyse odour mixtures in greater than two components in terms of the perceived order of components, and the identity of those components. Overall, the research demonstrated that two properties of simple binary odour mixtures, namely the temporal order and perceived strengths of components, are not primarily characterised by the transduction pathway those components putatively operate in human ORNs.Doctor of Philosophy (PhD)
15
Forestell, Catherine Ann. "Conditioned taste and odour preferences in rats". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq24842.pdf.
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Zhou, Xiaojing. "Odour emissions from swine operations in Manitoba". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62876.pdf.
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Lin, Xing Jun 1960. "Simulation of odour dispersion around natural windbreaks". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102997.
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The research objective was to calibrate a model to simulate odour dispersion downwind from natural windbreaks and then, use this model to observe the effect of windbreak characteristics and climatic conditions on the size of the odour dispersion plume. Computational fluid dynamic (CFD) models were used for the simulations because of their capability in reproducing turbulent wind conditions. The model was initially calibrated to ensure the proper velocity recovery ratio (VRR), and then to reproduce odour plumes measured in the field by three groups of four panellists.The visual and statistical analysis of the field panellist observations indicated that a windbreak with an optical porosity of 0.35 could reduce by 21% the length of the odour dispersion plume, as compared to a site without a windbreak. Also, these analyses indicated that the site with a windbreak offering an optical porosity of 0.55 had no significant impact on the length of the odour plume, as compared to the site without a windbreak.
The models selected for the simulations were the Fluent 6.2 standard k-epsilon and SST k-o models. Their odour dispersion calibration indicated that both models can accurately reproduce the field measured odour hedonic tone and odour concentration by transforming the odour mass fraction computed by the models into the hedonic tone with a power function, and then into the odour concentration with an exponential function. The correlations between the simulated and measured absolute HT and between the simulated and measured odour concentrations were statistically significant (P < 0.01). However, the SST k-o was preferred over the standard k-epsilon because it could physically better reproduce the high turbulence conditions created by the windbreak.
The SST k-o model simulations indicated that odour plume length was mostly affected by windbreak porosity and height, as well as distance from the source. In terms of climatic conditions, odour plume size was mostly affected for atmospheric stability conditions which generally established ambient wind speed and rate of change of temperature. Wind direction has an impact on the length of the odour plume and the formation of a fin intensifying odour concentration near the windbreak, where an angle of 45º produces the shortest odour plume and the largest fin.
Key words: Simulation; odour; dispersion; natural Windbreak; CFD.
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So, Tak-wing, e 蘇德榮. "Odour nuisance from restaurants and its control". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31252734.
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Singleton-Jones, Nicola. "A fundamental study into odour in footwear". Thesis, Nottingham Trent University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389685.
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So, Tak-wing. "Odour nuisance from restaurants and its control /". [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13498563.
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Hitchin, Suzanne. "Perceptual methods for environmental assessment : odour and landfill". Thesis, Cranfield University, 1998. http://dspace.lib.cranfield.ac.uk/handle/1826/11024.
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This thesis investigates the phenomenon of environmental annoyance from waste management, specifically landfill odours. The research study identifies the scope and significance of parameters that influence the extent of impact and includes these in a framework that can be used to influence the design and development of a population response model for odours. The research design considers the physiological, lifestyle and location factors that influence exposure and response to landfill odour and addresses three research objectives: • To produce a framework within which a community based population response model could be developed. • Determine and demonstrate the variability of response within a popUlation exposed to landfill odour. • To determine and demonstrate how spatial and temporal factors also contribute to the differential exposure and response of individuals to odour pollution. The research activity involved the design and implementation of an odour monitoring panel. Volunteers were recruited in the vicinity of two landfill sites where they monitored daily for odours for three months. This programme provided information on their routine activities and exposure to odour at the time. The thesis concludes by noting the following: • Location and climatic factors may generate more variability (at this scale of sample) than interpersonal differences. • The results from laboratory experiments examining hedonic properties were not repeated in the external environment. • The response levels between males and females were inconsistent with current knowledge and research assessing gender differences in the ability to detect odours. Additionally, the research demonstrates how data on the detection of odour in communities could be included in research activity that links olfactometry and the experience of odour in the environment.
22
Jinks, Anthony. "The perception of complex odour mixtures by humans /". [Richmond, N.S.W.] : School of Food Sciences, University of Western Sydney, 1999. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030507.151554/index.html.
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Sievert, Thorbjörn. "Behavioural responses of mice to predator odour components". Thesis, Linköpings universitet, Biologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119355.
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Having means to detect and avoid potential predators is a necessity for prey species. Most mammalian prey species are able to detect odours emitted by predators and to adapt their behaviour accordingly. These odour cues are therefore considered to act as semiochemicals. Predator odours consist of several dozen different odourants. In order to assess if single odourants elicit aversive behavioural reactions, predator-naïve CD-1 mice were presented with six odourants which are part of body-borne odours of different mammalian predator species. A two-compartment chamber was used in order to assess place-preference, motor activity and faecal excretions when the animals were simultaneously presented with a predator odourant and a blank control. Further trials were performed to assess whether the odourant concentrations had an influence on the behaviours. The only odourant that elicited a significant aversion was 3-methyl-1-butanethiol, a compound found in the anal gland secretion of skunks, when presented at a factor of 100 above the olfactory detection threshold of mice. Two other concentrations of 3-methyl-1-butanethiol did not elicit significant behavioural changes. Based on the present study, only one out of six selected predator odourants elicited a significant aversive response in CD-1 mice. This suggests that more than one odour component, or perhaps even the full mixture of odourants, may be necessary for CD-1 mice to respond to a predator odour with aversive behaviour.
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Bartlett, Jon G. "Automated gas and odour sensing using semiconducting polymers". Thesis, University of Manchester, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284116.
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Lytridis, Christodoulos. "Cooperative robotic search strategies for odour source localisation". Thesis, University of Portsmouth, 2005. https://researchportal.port.ac.uk/portal/en/theses/cooperative-robotic-search-strategies-for-odour-source-localisation(9cafb45a-5881-42cc-956c-514ead3298d8).html.
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Tsakaloyannis, Michael K. "Development of a regulatory strategy for odour impact assessment". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29633.pdf.
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DeBruyn, Jacob C. "Biofiltration for odour control from swine housing in Manitoba". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ57529.pdf.
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Sjöström, Desirée. "Behavioural responses in mice exposed to predator odour components". Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108103.
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It is essential for prey species to be able to detect predators to avoid them. The sense of smell is used by a number of prey species for this purpose. The aim of the present study was to assess if one of the odourants that make up a predator odour is sufficient to induce a behavioural response in mice (Mus musculus). Two predator odourants were used, 2,2-dimethylthietane and methyl-2-phenylethyl sulfide, which are both found in the secretions of natural predators of mice. An odourant found in fruits, n-pentyl acetate, was also used. All three odourants were presented at a concentration that was a factor of 100 above the olfactory detection threshold of mice. Ten adult predator-naïve CD-1 mice were individually put in a two-compartment chamber one of which contained an odourant while the other contained a near-odourless solvent (diethyl phthalate). The results indicated that methyl-2-phenylethyl sulfide was actively avoided by the mice. Towards 2,2-dimethylthietane and n-pentyl acetate, in contrast, the mice behaved indifferent. Further, the results suggest a significant correlation between the number of switches between the two compartments of the test chamber and the test sessions when the animals were presented with n-pentyl acetate, but not when they were presented with the predator odourants. The results support the notion of an innate fear response towards the predator odourant methyl-2-phenylethyl sulfide in mice, but further studies with more animals and different concentrations of the odourants are necessary.
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Beaman, A. L. "A new approach to the assessment of odour nuisance". Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382967.
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Chong, Kwok Ying. "Encoding of odour blends in the moth antennal lobe". Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/30242.
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Olfaction is a vital sense that informs moths of their environment, and as such moths are adept at chemical sensing. Natural odours are often complex mixtures of different compounds. Thus, odour components can interact along the olfactory pathway in a nonlinear fashion such that the mixture is not perceived simply as the sum of its components. Here an investigation is made into possible nonlinear interactions in the olfactory system of moths at two stages along the olfactory pathway. These are the input to and the output from the antennal lobe, the region of the insect brain responsible for the first neural processing of odour information.;The input to the antennal lobes is the neural representation of odours carried by the receptor neurons. By use of a calcium sensitive dye, this activity was observed optically as odour-evoked changes in Ca2+ concentration in the moth Spodoptera littoralis. This reveals the input pattern to functionally distinct neuropil in the antennal lobes, the so-called glomeruli. Such a calcium imaging analysis requires the identification of the glomeruli, and a novel method was developed to facilitate the automatic identification of olfactory glomeruli. By applying unsupervised clustering analysis to sets of calcium images, glomeruli were functionally identified. Binary odour blend responses were then analysed for nonlinear interactions, but no strong interactions were found.;The output from the antennal lobe, the projection neuron responses, was assessed by computational models. It was demonstrated in pheromone processing models that a spatiotemporal odour code is better able to encode for blend ratios than a spatial code. And it was shown that a spatiotemporal general odour model produces nonlinear component interactions, despite the data-motivated input having none.
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Pugh, Simon. "Taint and odour phenomena in carton-board packaging systems". Thesis, University of Leeds, 1998. http://etheses.whiterose.ac.uk/1765/.
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Unsaturated lipids exist in carton-board and can be the precursors of odorous compounds. Two unsaturated lipids that can be present are oleic acid (cis 9-octadecenoic acid) and linoleic acid (cis, cis 9,12-octadecadienoic acid). These lipids can be present in the free acid form, as alkyl ester derivatives and in the triglyceride form. These lipids are able to undergo oxidation. Such oxidation leads to the formation of a number of odorous compounds. Oxidation proceeds via hydroperoxide intermediates to produce aldehydes, ketones, alcohols, furans, lower fatty acids, alkenes and alkanes, the majority of which are odorous. The aldehydes, in particular, have very low odour and taste detection thresholds, needing to be present only in very small amounts in a packaging material to cause a taint problem. Typically, taints associated with these compounds are described as 'rancid', 'pungent', 'soapy' and 'green'. Static headspace GC/MS analyses have identified a number of odorous compounds formed from oxidation reactions, within standard samples of wood pulp obtained from carton-board manufacturers. These oxidation reactions are affected to various extents, by a number of factors such as the temperature, the nature of the fatty acids, the presence of oxidation catalysts such as transition metal ions, the availability of oxygen, the humidity and the presence of photosensitising agents. Breakdown pathways and reaction schemes are presented in context as are kinetic details of odorous product formation. UV curable inks are commonly used in the printing of carton-board packaging materials. These inks contain photoinitiators which have the potential to affect the oxidation rate and extent of formation of unsaturated lipids, resulting in the formation of odorous compounds within the carton-board matrix. Static headspace analysis, dynamic headspace analysis and vacuum extraction procedures have identified a number of volatile components, that are odorous, in the inks and varnishes. These compounds, which include by-products arising from photoinitiators, amine photoactivators and residual solvents, have the potential to cause 'ink', 'varnishy', 'plasticy' taints in a packaged food system if these components are able to migrate from the carton.
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Stubbs, Shannon. "Behavioural responses of wolves (Canis lupus) and dogs (Canis lupus familiaris) to the odour of mammalian blood and to a blood odour component". Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-173151.
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Domestication is accompanied by marked changes in the phenotype of the domesticated form of a species relative to its wild ancestor. The domestic dog and its wild ancestor, the wolf, are a widely used model system to study the effects of domestication on cognition and behaviour. The aim of this study was therefore to compare the behavioural responses of wolves (Canis lupus) and domestic dogs (Canis lupus familiaris) to different odour stimuli. To this end, wooden logs were impregnated with one of four odours and repeatedly placed into the enclosure of a wolf or dog pack. The dogs (n=10) and wolves (n=9) both performed a significantly higher number of interactions with the wooden logs when these were impregnated with real blood compared to the blood odour component trans-4,5-epoxy-(E)-2-decenal, the fruity odour iso-pentyl acetate and the solvent diethyl phthalate. No significant difference in the frequency of interactions per animal was found between the wolves and dogs with any of the four odour stimuli. Sniffing was the most frequent behaviour in both wolves and dogs, followed by licking, biting, toying, and pawing. The only qualitative difference in behaviour was that the dogs, but not the wolves, displayed guarding behaviour when presented with the odorized wooden logs. The results of the present study suggest that domestication had little, if any, effect on olfactory behaviour in domesticated dogs. The results also indicate that odour-impregnated wooden logs are a suitable method of olfactory enrichment for captive wolves and domestic dogs.
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Hotson, Suzanne. "A longitudinal study of cortical EEG to olfactory stimulation, involving inter- and intra-subjective responses". Thesis, University of Warwick, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386869.
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Searle, Graham Ellis. "Dynamic modelling of electronic nose systems". Thesis, University of Warwick, 2002. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251118.
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Russell, Benjamin Gallard School of Biological Earth & Environmental Sciences UNSW. "The role of odour in Australian mammalian predator/prey interactions". Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2005. http://handle.unsw.edu.au/1959.4/25144.
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Odour plays an important role in many predator/prey interactions. In the northern hemisphere, many mammalian prey species have been shown to respond to predator odours. It is also widely assumed that mammalian predators utilise odours to locate their prey. This thesis explores the importance of odour in Australian mammalian predator/prey interactions. Responses of native Australian species to the faecal odour of two predators; the native tiger quoll Dasyurus maculatus and the introduced red fox Vulpes vulpes, were evaluated through live-trapping and focussed behavioural studies of captive animals. Tiger quoll responses to prey olfactory cues were investigated in a captive experiment. Native rodents (bush rats Rattus fuscipes, swamp rats R. lutreolus and eastern chestnut mice Pseudomys gracilicaudatus) equally avoided traps scented with either quoll or fox faeces, and in captive experiments, bush rats and swamp rats reduced their average speed in response to both predator odours. Of the marsupial species, northern brown bandicoots Isoodon macrourus and common brushtail possums Trichosurus vulpecula were captured more frequently in quoll-scented traps than unscented traps or foxscented traps, while captures of brown antechinus Antechinus stuarttii, long-nosed bandicoots Perameles nasuta and southern brown bandicoot I. obesulus were unaffected by the either predator odour. In captive experiments, brown antechinus, long-nosed and northern brown bandicoots decreased their foraging in response to both predator odours, and spent less time in areas scented with quoll faeces. Tiger quolls didn't appear to detect odour sources from a distance of >65 cm, but they did follow scent trails and spent more time in areas scented with the urine and faeces of potential prey. Chemical analysis revealed no common components in fox and quoll odour which prey species could be responding to. Therefore, these native species have evolved to respond to fox odour since foxes were introduced to Australia 130 years ago. The stronger response of native rodents to fox odour may be a legacy of their co-evolution with canid predators prior to entering Australia. A better understanding of how odour is utilised in Australian predator/prey interactions may lead to a greater ability to protect Australia's unique mammalian fauna from introduced predators.
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Gorgy, Tamer G. Alexan. "Validation of an air dispersion model for odour impact assessment". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19687.
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Odorous emissions can result in physiological and psychological discomfort when released and subsequently perceived by people in the neighbouring community. Regulatory agencies, as well as members of the industrial and agricultural sectors, are obliged to develop methods for mitigating or preventing odorous impacts on communities. It has been proposed that combined application of the Industrial Source Complex-Short Term3 (ISCST3) dispersion model and the Odour Impact Model (OIM) can provide an improved basis for predicting odorous impacts. The objective of this investigation was to validate the use of ISCST3 and the OEM to predict the impact of emissions from a hog farm in rural Quebec in terms of probability of response and degree of annoyance. This was accomplished by predicting the impact through modelling for comparison with on-site field measurements that were conducted on three different occasions. The ISCST3 dispersion model was used to predict odour concentrations in the region in the immediate vicinity of the farm. Subsequently, the predicted concentrations were used in combination with the dose-response curves of the OIM to predict the probability of response and annoyance that would be experienced in the region surrounding the hog farm. When compared to field measurements, it was concluded that the model resulted in reasonably accurate predictions provided that the predicted one-hour time-averaged concentrations from the dispersion model were first transformed to one-minute timeaveraged values. Overall, once this transformation was made, there was a tendency to slightly under predict the probability of response and to slightly over predict the degree of annoyance. The difference in these tendencies may result from differences in the ways that odour are characterized in the laboratory as compared to how they are experienced in the field.
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Wong, Ying-kin, e 黃英健. "Odour control and management in Hong Kong sewage treatment infrastructures". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194556.
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Many complaints were received from the residential area around the Shatin Sewage Treatment Works (STSTW) about the presence of odour. The dominant odour marker H2S was selected to be studied. A review of the odour measurement and sampling methods, together with the specification of the standard limits and health effects were made. The formation process of H2S was investigated and the abatement and control measures in terms of physical, chemical and biological techniques were compared. The monthly rate of H2S emission in the atmosphere was calculated from the soluble sulfide and the measured wastewater flow at the inlet works, primary sedimentation tanks, aeration tanks, and sludge digestive and storage tanks, and the H2S mapping was carried out at the same places. Meteorological data including wind speed, wind direction, temperature and pressure were collected. The effect of temperature and pH on H2S generation is shown, and the effectiveness of odour control and deodourization processes was studied. A Gaussian dispersion model of Industrial Source Complex version 3 (ISC3) was applied in predicting the ground H2S level at various air sensitive receivers in the vicinity of STSTW. None of the places exceeded the recommended H2S concentration of World Health Organization (WHO) and the odour is a localized problem in STSTW of 35% area having H2S ranging in 0.01--‐0.023ppm. Recommendations are suggested in both short-term improvement in operation and maintenance practice and long-term design and construction of sewage treatment facilities.published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management
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Enayet, Samia. "Evaluation of odour abatement causes following electro-dewatering of biosolids". Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123224.
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Biosolids being recycled to the land for agriculture is not only cost-effective for municipalities but it is also beneficial to the environment. To protect public and environmental health, however, land application of biosolids is regulated for concentrations of pathogens and chemical contaminants, and for production of odours. Electro-dewatering (ED) of residual biosolids from wastewater treatment is a newly commercialized technology which can produce a drier biosolids cake compared to other advanced dewatering technologies. Additionally, it has been demonstrated that ED inactivates pathogen indicators below the detection limit and reduces the regrowth potential. In the current study, using olfactometry and headspace gas chromatography - mass spectrometry (GC/MS), reduced production of odours during storage of dewatered biosolids was documented, and possible mechanisms leading to this reduction were examined.The study compared centrifuged secondary biosolids as the untreated sample control with the same biosolids that had been either electro-dewatered for 10 min or simply heat-treated for 10 min as a secondary control. These samples were incubated at room temperature under anaerobic conditions. Qualitative analysis of the head space by a trained olfactometric panel showed that ED biosolids possessed lower perceived odour concentrations when characterized by detection threshold and recognition threshold compared to the untreated and the heat-treated biosolids (detection thresholds were 13,000 for ED biosolids, 25,000 for untreated biosolids, and 18,000 for heat-treated biosolids). Quantitative analysis by GC/MS of reduced sulphur compounds (methanethiol, dimethyl sulphide and dimethyl disulphide) showed relatively high concentrations for the untreated and heat treated samples, but these compounds remained below the detection limit (78 ppmv for methanethiol, 59 ppmv for dimethyl sulphide and 8 ppmv for dimethyl disulphide) for the ED samples during 14 days of anaerobic incubation. To investigate the reason for the lower odour production by ED biosolids, several factors were examined: (1) the lower pH of the electro-dewatered biosolids (pH 4.5-4.8 vs. pH 6.8-7.5 for the untreated and heat-treated biosolids), (2) the removal of odour precursors by ED, (3) the production of inhibitory compounds during ED. The low pH hypothesis was tested by increasing the pH of the ED biosolids to the level found in the untreated biosolids before anaerobic incubation. Increasing the pH of ED biosolids led to an increase in methanethiol generation. This suggests that lowering the pH of biosolids is one of the main factors causing the abatement of odour production by ED. The removal of odour precursor hypothesis was tested by adding back the filtrate extracted by ED. As the filtrate had a very high pH of 12.8, which also changed the pH of the ED biosolids, the filtrate pH was manipulated such that the pH of the resulting biosolids would be either ~4.5 or ~7. As in the pH-specific experiments, methanethiol emissions were not detected for all samples with a low pH, whereas methanethiol emissions from the high pH samples were increased in the ED biosolids with added filtrate. These methanethiol emissions were above those of the untreated, ED biosolids without filtrate and the heat-treated biosolids. These final results indicate that the dominant factor responsible for reduced odours in ED biosolids is the low pH, but that the removal of precursors may also contribute to lowering odour production. Once these factors were taken into account, there was no clear evidence that ED produced inhibitory compounds. Finally, these experiments confirmed that bacterial pathogen indicators did not regrow under the conditions tested. Therefore, it can be concluded that, under the conditions tested, ED achieved irreversible inactivation of pathogen indicator organisms and reduced odour production by lowering the pH.L'électro-déshydratation (ED) des biosolides résiduels découlant du traitement des eaux usées est une technologie nouvellement commercialisée qui peut produire des biosolides plus secs que d'autres technologies de déshydratation avancées. Dans l'étude présentée dans ce mémoire, la réduction de la production d'odeurs durant l'entreposage des biosolides déshydratés a été documentée et les mécanismes possibles conduisant à cette réduction ont été examinés en utilisant l'olfactométrie et la spectrométrie de masse (GC/MS) en phase gazeuse de l'espace de tête. L'étude a comparé des biosolides secondaires centrifugés en tant que contrôle (échantillons non traité) avec les mêmes biosolides qui avaient été soit électro-déshydratées pendant 10 min, soit simplement traité à la chaleur pendant 10 min comme un contrôle secondaire. L'analyse qualitative de l'espace gazeux au-dessus des échantillons par un panel olfactométrique a montré que les biosolides électro-déshydratés produisaient des concentrations perçus d'odeurs inférieure selon les seuils de détection et de reconnaissance des odeurs par rapport aux échantillons non traités ou traités à la chaleur (seuils de détection étaient 13 000 pour les biosolides électro-déshydratés, 25 000 pour les biosolides non traités, et 18 000 pour les biosolides traités à la chaleur). L'analyse de GC/MS des composés soufrés réduits (méthanethiol, sulfure de diméthyle et le disulfure de diméthyle) a montré des concentrations relativement élevées pour les échantillons non traités et traités à la chaleur, mais ces composés sont restés sous la limite de détection pour les échantillons électro-déshydratés et incubés en anaérobie pendant 14 jours.Pour determiner la cause de la réduction de la production d'odeur par les biosolides électro-déshydratés, plusieurs hypothèses ont été émises: (1) le pH inférieur des biosolides électro-déshydratée (pH 4,5-4,8 vs pH 6.8 à 7.5 pour les biosolides non-traités et traités thermiquement), (2) l'élimination des précurseurs d'odeur par le processus d'électro-déshydratation, (3) la production de composés inhibiteurs au cours de l'électro-déshydratation. L'hypothèse d'un pH faible a été testée en augmentant le pH des biosolides électro-déshydratées au niveau des biosolides non traitées avant l'incubation anaérobie. L'augmentation du pH des boues électro-déshydratées a conduit à une augmentation de la production méthanethiol. Ceci suggère que l'abaissement du pH des boues est l'un des principaux facteurs responsables de la réduction de la production d'odeur par électro- déshydratation. L'hypothèse de la suppression du précurseur d'odeur a été testée en rajoutant le filtrat extrait par l'électro-déshydratation. Comme le filtrat présente un pH très élevé (12.8), le filtrat pH a été manipulé de telle sorte que le pH des biosolides résultant serait soit de ~ 4.5 ou de ~ 7. Comme dans les expériences spécifiques au pH, les émissions de méthanethiol n'ont pas été détectées pour les échantillons dont le pH était bas, alors que les émissions méthanethiol à partir des échantillons à pH élevé ont augmentés dans les biosolides électro-déshydratées avec filtrat ajoutée. Ces émissions de méthanethiol étaient supérieures à ceux des biosolides électro-déshydratées sans filtrat, des biosolids non traités et des biosolides traités à la chaleur. Ces derniers résultats indiquent que le facteur dominant responsable de la réduction des odeurs dans les biosolides électro-déshydratées est le faible pH, mais que l'élimination des précurseurs peut également contribuer à réduire la production d'odeurs. Une fois que ces facteurs eurent été pris en compte, il n'y avait pas de preuve claire que l'électro-déshydratation produit des composés inhibiteurs. Par conséquent, on peut conclure que, dans les conditions testées, l'électro-déshydratation atteint une inactivation irréversible d'organisme indicateur d'agent pathogène et a réduit la production d'odeur par abaissement du pH.
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Anglesea, John Robert Edward. "The optimisation of multisensor arrays in electronic odour sensing systems". Thesis, University of Derby, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270027.
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Elshaw, Mark. "An assessment of the performance of electronic odour sensing systems". Thesis, University of Derby, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312607.
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Rennie, Paul John. "The skin microflora and the formation of human axillary odour". Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246346.
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Dawes, C. A. "Odour pollution problems within the district of the Wrekin Council". Thesis, Aston University, 1987. http://publications.aston.ac.uk/9699/.
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This thesis is concerned with various aspects of Air Pollution due to smell, the impact it has on communities exposed to it, the means by which it may be controlled and the manner in which a local authority may investigate the problems it causes. The approach is a practical one drawing on examples occurring within a Local Authority's experience and for that reason the research is anecdotal and is not a comprehensive treatise on the full range of options available. Odour Pollution is not yet a well organised discipline and might be considered esoteric as it is necessary to incorporate elements of science and the humanities. It has been necessary to range widely across a number of aspects of the subject so that discussion is often restricted but many references have been included to enable a reader to pursue a particular point in greater depth. In a 'fuzzy' subject there is often a yawning gap separating theory and practice, thus case studies have been used to illustrate the interplay of various disciplines in resolution of a problem. The essence of any science is observation and measurement. Observation has been made of the spread of odour pollution through a community and also of relevant meterological data so that a mathematical model could be constructed and its predictions checked. It has been used to explore the results of some options for odour control. Measurements of odour perception and human behaviour seldom have the precision and accuracy of the physical sciences. However methods of social research enabled individual perception of odour pollution to be quantified and an insight gained into reaction of a community exposed to it. Odours have four attributes that can be measured and together provide a complete description of its perception. No objective techniques of measurement have yet been developed but in this thesis simple, structured procedures of subjective assessment have been improvised and their use enabled the functioning of the components of an odour control system to be assessed. Such data enabled the action of the system to be communicated using terms that are understood by a non specialist audience.
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Freudenthal, Kai. "Odour control by selective absorption using solubility agents and washing oils". [Hamburg] [TuTech Innovation], 2009. http://d-nb.info/999304356/34.
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Poletti, Sophia C., Annachiara Cavazzana, Cagdas Guducu, Maria Larsson e Thomas Hummel. "Indistinguishable odour enantiomers: Differences between peripheral and central-nervous electrophysiological responses". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230788.
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The ability of humans to discriminate enantiomeric odour pairs is substance –specific. Current literature suggests that psychophysical discrimination of odour enantiomers mainly depends on the peripheral processing at the level of the olfactory sensory neurons (OSN). To study the influence of central processing in discrimination, we investigated differences in the electrophysiological responses to psychophysically indistinguishable (+)- and (−)- rose oxide enantiomers at peripheral and central-nervous levels in humans. We recorded the electro-olfactogram (EOG) from the olfactory epithelium and the EEG-derived olfactory event-related potentials (OERP). Results from a psychophysical three alternative forced choice test indicated indistinguishability of the two odour enantiomers. In a total of 19 young participants EOG could be recorded in 74 and OERP in 95% of subjects. Significantly different EOG amplitudes and latencies were recorded in response to the 2 stimuli. However, no such differences in amplitude or latency emerged for the OERP. In conclusion, although the pair of enantiomer could be discriminated at a peripheral level this did not lead to a central-nervous/cognitive differentiation of the two stimuli.
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Kowadlo, Gideon. "Robot odour localisation in enclosed and cluttered environments using naïve physics". Monash University. Faculty of Engineering. Department of Electrical and Computer Systems Engineering, 2007. http://arrow.monash.edu.au/hdl/1959.1/53471.
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Odour localisation is the problem of finding the source of an odour or other volatile chemical. It promises many valuable practical and humanitarian applications. Most localisation methods require a robot to reactively track an odour plume along its entire length. This approach is time consuming and may be not be possible in a cluttered indoor environment, where airflow tends to form sectors of circulating airflow. Such environments may be encountered in crawl-ways under floors, roof cavities, mines, caves, tree-canopies, air-ducts, sewers or tunnel systems. Operation in these places is important for such applications as search and rescue and locating the sources of toxic chemicals in an industrial setting. This thesis addresses odour localisation in this class of environments. The solution consists of a sense-map-plan-act style control scheme (and low level behaviour based controller) with two main stages. Firstly, the airflow in the environment is modelled using naive physics rules which are encapsulated into an algorithm named a Naive Reasoning Machine. It was used in preference to conventional methods as it is fast, does not require boundary conditions, and most importantly, provides approximate solutions to the degree of accuracy required for the task, with analogical data structures that are readily useful to a reasoning algorithm. Secondly, a reasoning algorithm navigates the robot to specific target locations that are determined with a physical map, the airflow map, and knowledge of odour dispersal. Sensor measurements at the target positions provide information regarding the likelihood that odour was emitted from potential odour source locations. The target positions and their traversal are determined so that all the potential odour source sites are accounted for. The core method provides values corresponding to the confidence that the odour source is located in a given region. A second search stage exploiting vision is then used to locate the specific location of the odour source within the predicted region. This comprises the second part of a bi-modal, two-stage search, with each stage exploiting complementary sensing modalities. Single hypothesis airflow modelling faces limitations due to the fact that large differences between airflow topologies are predicted for only small variations in a physical map. This is due to uncertainties in the map and approximations in the modelling process. Furthermore, there are uncertainties regarding the flow direction through inlet/outlet ducts. A method is presented for dealing with these uncertainties, by generating multiple airflow hypotheses. As the robot performs odour localisation, airflow in the environment is measured and used to adjust the confidences of the hypotheses using Bayesian inference. The best hypothesis is then selected, which allows the completion of the localisation task. This method improves the robustness of odour localisation in the presence of uncertainties, making it possible where the single hypothesis method would fail. It also demonstrates the potential for integrating naive physics into a statistical framework. Extensive experimental results are presented to support the methods described above.
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Bell, Rati. "Anterior and lateral thalamic lesions in object-odour paired associate learning". Thesis, University of Canterbury. Biological Sciences, 2007. http://hdl.handle.net/10092/1450.
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Diencephalic amnesia is thought to be the result of damage to a single thalamic structure that is responsible for the memory impairment. However, an alternative view is that different thalamic structures contribute to the memory impairment in subtly different ways. Paired-associate learning is one important measure of learning and memory that is highly sensitive to disruption in people with amnesia or dementia. The current study will investigate the influence of lesions to two thalamic subregions, the anterior thalamic nuclei (AT) and the lateral thalamic nuclei (LT) in an object-odour paired associate learning task. Each of these subregions has been suggested by the literature as critical for amnesia after thalamus injury. The current study does not involve a place/ space component. Both AT and LT lesions caused impairments in the object-odour paired associate task, but not in the simple discrimination tasks. The results of this study provide new evidence to suggest that the anterior thalamic region may be responsible for more than spatial memory processing. This result is inconsistent with those of Aggleton & Brown (1999) that consider the AT to be part of an 'extended hippocampal system'. The deficits observed from LT lesions in this study provide new insight into the lateral thalamic region's role in pattern processing.
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Carlsson, Mikael A. "A sensory map of the odour world in the moth brain /". Alnarp : Swedish University of Agricultural Sciences, 2003. http://diss-epsilon.slu.se/archive/00000339/.
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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003.Appendix consists of reprints and manuscripts of five papers co-authored with others. Includes bibliographical references. Also partially available electronically via World Wide Web in PDF format; online version lacks appendix.
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Portman, Katherine Louise. "Characterising the binding interactions and thermodynamics of odour binding protein 3". Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/13704/.
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Odour Binding Proteins (OBPs) are found in the olfactory system of a range of species. Whilst invertebrate OBP function is well understood, the exact function of these proteins in the vertebrate nasal mucus is not fully understood. Multiple subtypes of rat OBPs have been identified and found to share less than 30% sequence identity. Studies have suggested each rat OBP binds to particular sets of odours, which may afford them a particularly important role within the olfactory system, pre-sorting odours. This study focuses on OBP3, closely examining the binding interaction of this protein with a range of odours. This has been done using Isothermal Titration Calorimetry which revealed that the binding of the highest affinity ligands, the heterocyclic compounds, is enthalpically driven. A defined odour series, the gamma-lactones showed that despite increasing ligand size and hydrophobicity, the free energy of binding of these ligands is maintained. Interactions with both 2-isobutylthiazole and the gamma-lactones were examinedusing NMR spectroscopy, which required the NMR assignment of OBP3 to be determined. In addition a homology model of OBP3 was created in order to structurally map the per-residue changes of OBP3 upon binding. It has been found that OBP3 is able to subtly adjust in order to accommodate each of these ligands. Protein engineering of the OBP3 binding pocket has been used to highlight the importance of its size and hydrophobicity. The importance of a tyrosine residue that appears to cover the opening to the binding pocket and is conserved across both the aBPs and the lipocalins family they are part of, has been demonstrated. Mutagenesis has also revealed the importance of a number of key residues for the binding of 2-isobutylthiazole. The ability to rationally improve the affinity of OBP3 for a particular odour has also been demonstrated.
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Waldmann, T. "The aversive effect of the odour of dimethylamine on rat behaviour". Thesis, University of Ulster, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292988.
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Legha, Prem, University of Western Sydney, of Science Technology and Environment College e of Science Food and Horticulture School. "Molecular structure and odor mixture perception". THESIS_CSTE_SFH_Legha_P.xml, 2004. http://handle.uws.edu.au:8081/1959.7/549.
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The sense of smell is a primal sense for humans as well as animals.In everyday life the smells encountered are composed of dozens, even hundreds of odors; few arise from a single odorant. Enormous numbers of odors occur due to the vast variation in the concentration, size and structure of odorant molecules that makes olfaction differ from simpler visual or auditory dimensions. Accordingly, little is known about the ways in which changes in molecular structure and concentration of individual odorants change odor quality. Also, currently not much is understood about synergism/antagonism, how one odorant masks or suppresses another in mixtures and there is no method for predicting which odor will be suppressed. The two main objectives of this thesis were to determine whether a part of a molecular structure rather than the whole structure plays a key role in odor quality and whether a key part of a molecule can be used to choose antagonists for that odorant. For this study three classes of musks and two potential antagonists were used. The results of the study are discussed in some detail. It is concluded that future studies of the importance of molecular structure in mixture interactions require substantially more information on the relation between structure and odor quality to allow systematic studies to be developed. In summary the two hypotheses investigated were not supported by the results. Importantly, however, they do support the view that it is likely that odor quality is dependent on the whole structure of an odorant not a single feature.Master of Science (Hons)