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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Svavelväteproblematiken i svenska spillvattensystem : En studie i hur olika åtgärder har fungerat

Spengler, Clara January 2020 (has links)
Svavelväte, H2S, är en giftig och illaluktande gas. Den karakteristika ''ruttet ägg''-lukten kan kännas redan 0.02ppm och det hygieniska gränsvärdet för exponering under en arbetsdag ligger på 5ppm, enligt arbetsmiljöverkets restriktioner. Dessutom är gasen korrosiv på betong och övrig utrustning och minskar därmed livslängden på ledningssystem. Svavelväte bildas i avloppsvatten under anaeroba förhållanden vilka typiskt uppstår i spillvattenledningar med långa uppehållstider. Syftet med detta arbetet var att kartlägga vilka åtgärder för att minska bildningen av svavelväte som användes, hur dessa har fungerat i praktiken samt försöka hitta ett samband mellan vilka åtgärder som passar i vilket typ av system. Detta gjordes med en grundläggande litteraturstudie samt datainsamling via telefon, e-mail och intervjuer. Studien visar att dosering med kemikalier var den vanligaste åtgärden följt av någon typ av luftningsanordning. Mätningar på hur svavelvätehalter påverkas i samband med dessa åtgärder var dock svåra att hitta.  Arbetet visade på en komplexitet i bildandet av svavelväte. De fysiska förutsättningarna i ledningarna såsom dimensioner, flödeshastighet, temperatur etc. påverkar också svavelvätebildingen. Förutsättningarna i ledningarna beror av många faktorer vilka ständigt varierar. Samtliga beskrivna åtgärder har enligt de kommuner där de införts och testats haft önskad effekt utifrån en subjektiv bedömning. Studien visar att grundläggande mätningar är nödvändiga för att klargöra vilka åtgärder som är mest effektiva vid givna förutsättningar. För att i framtiden kunna tackla detta antagligen växande problem i svenska ledningsnät bör alltså fler och noggrannare mätningar göras. Mätningarna bör göras både innan och efter en åtgärd sats in samt uppföljande mätning för att se om åtgärden bibehåller önskad effekt. En databas med denna typ av mätningar skulle dels gynna framtida forskning, dels hjälpa kommuner att välja rätt metod för att lösa svavelvätereleaterade problem. / Hydrogen sulphide is a toxic gas with a malodorous smell. Even in very low amounts, 0.02ppm, the rotten egg odor is noticable. The limit exposure per day is 5ppm according to The Swedish Work Environment Authority's restrictions. In addition, the gas is very corrosive to concrete and equipment, thus reducing the lifetime of wastewater collection systems. Hydrogen sulphide is formed in wastewater under anaerobic conditions, which typically occur in wastewater systems with long residence times. The aim of this study was to find which methods are used to reduce the formation of hydrogen sulphide. How these have preformed in practice and try to find a connection between which methods are suitable in which type of system. This was done with a literature study as well as data collection via telephone, e-mail and interviews.  Dosing with chemicals proved to be the most common method to reduce hydrogen sulphide, followed by some kind of ventilation devices. Measurements of hydrogen sulphide content in connection with these methods was, however, difficult to find among the contacted users.  This study showed a complexity in the formation of hydrogen sulphide since the conditions in wastewater collection systems depend on many factors which constantly varies. According to the municipalities where methods were introduced and tested, the desired effect based on a subjective assessment was reached. The study shows that measurements are necessary to clarify which methods are most effective under given conditions.  In order to deal with this possibly growing problem in Swedish waste water collection systems, more accurate data collection should be done. Both before, after and follow up data, regarding the intervention should be collected when studying this issue. Doing so would greatly benefit future research and help municipalities in solving this problem.
82

Behavioural responses of wolves (Canis lupus) and dogs (Canis lupus familiaris) to the odour of mammalian blood and to a blood odour component

Stubbs, Shannon January 2019 (has links)
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.
83

Myš, potkan, krysa: prostor, pach a metody detekce / Mice and Rats: Space, Smell and Methods of Detection

Kaftanová, Barbora January 2018 (has links)
The coexistence of humans and rodents lasts from the beginnings of the history of agriculture. Many rodent populations accepted to synanthropic way of life and as commensals accompany human societies until today. In the first study we wanted to find out, how the evolution of non-commensal rodent species, a Cypriot mouse (Mus cypriacus), was influenced by people. This endemic island species evolved on the Cyprus Island without presence of any mammalian competitors or predators. In last 10.000 years humans arrived on the island, bringing several mammalian species, which affected the environment markedly. A black rat (Rattus rattus) is now dominant species there and presumably it is an important competitor for the Cypriot mouse. We supposed that the mice should avoid its odour. Nevertheless the rats odour was preferred by the mouse, probably as an odour of phylogenetically related species. On the contraty, the odour of domestic cat (species, which is also widespread on the island), was avoided. In conclusion, the long-term isolation from mammalian predators did not affect the antipredatory reactions of the Cypriot mouse. Our next study was focuse on changes in behavioural strategies of different populations of mice: the main question was how the commensal way of life affects their exploratory...
84

Ultrastructure and chemical analysis of osmophores in Apocynaceae / Ultraestrutura e análise química de osmóforos em Apocynaceae

Capelli, Natalie do Valle 31 January 2018 (has links)
Apocynaceae presents the flowers with the highest degree of synorganization among the eudicots and highly elaborated pollination mechanisms associated with the high diversity of glands. The osmophore stands out as responsible to produce a floral scent which attracts pollinators and, despite its fundamental relevance for pollination, its structure and mechanism of production and release of the perfume is essentially unknown in Apocynaceae. This present work aims to characterize morphologically and ultrastructurally the osmophores of Apocynaceae, besides chemically identifying the compounds that constitute the floral scent. Species from two subfamilies were selected to describe the diversity of osmophores and types of scent in the family. The osmophores were firstly located histochemically and, later, this region was processed for transmission electron microscopy. Micromorphological analysis was performed by scanning electron microscopy, and the identification of volatile oils made by GC-MS. Osmophores are located on the adaxial surface of the free portion of the petals. They varied in the shape of epidermal cells, striation of the cuticle and presence of trichomes. This gland is mostly formed by secretory epidermis and parenchyma, except in Plumeria, where the osmophores are exclusively epidermal. The secretory cells presented thick walls in the Asclepiadoideae and secretion produced by plastids and SER in all species. Several vesicles perform the intercellular transport of secretion, as well as its release to the environment. However, Plumeria and Ditassa transfer the secretion produced to the vacuole before releasing it, and Tabernaemontana has a mixed release process. The composition of the scent varied among species, with great production of hydrocarbons, alcohols, ketones or monoterpenes depending on the species. Apocynaceae presents a high morphological and metabolic diversity in the osmophores which cannot be correlated with their morphology, subcellular organization, period of secretion release or pollination syndrome. This is the first comprehensive structural study of osmophores in this family that points out to very distinct evolutionary processes that may be related to multiple emergences in the phylogeny and speciesspecific associations with pollinators / Apocynaceae apresenta as flores com o maior grau de sinorganização das eudicotiledôneas e mecanismos de polinização altamente elaborados associados à mais alta diversidade de glândulas. O osmóforo destaca-se como responsável pela produção do perfume floral para atração dos polinizadores e, a despeito de sua importância fundamental para a polinização, a sua estrutura e mecanismo de produção e liberação do perfume é praticamente desconhecido nas Apocynaceae. O presente trabalho tem o propósito de caracterizar morfológica e ultraestruturalmente os osmóforos de Apocynaceae, além de identificar quimicamente os compostos que constituem o perfume floral. Espécies de duas subfamílias foram selecionadas, visando descrever a diversidade de osmóforos e tipos de perfume na família. Primeiramente, os osmóforos foram localizados histoquimicamente e, posteriormente, essa região foi processada para microscopia eletrônica de transmissão. Análise micromorfológica foi realizada através de microscopia eletrônica de transmissão. Análise micromorfológica foi realizada através de microscopia eletrônica de varredura e a identificação dos óleos voláteis, através de GC/MS. Os osmóforos estão localizados na superfície adaxial da porção livre das pétalas. Eles variaram quanto ao formato das células epidérmicas, ornamentação da cutícula e presença de tricomas. Esta glândula é, em sua maioria, formada por epiderme e parênquima secretores, exceto em Plumeria, onde os osmóforos são exclusivamente epidérmicos. As células secretoras apresentaram paredes espessas nas Asclepiadoideae e secreção produzida pelos plastídeos e REL em todas as espécies. Diversas vesículas realizam o transporte intercelular da secreção, assim como a sua liberação para o meio externo. Contudo, Plumeria e Ditassa transferem a secreção produzida para o vacúolo antes de liberá-la e Tabernaemontana possui processo de liberação misto. A composição do perfume variou entre as espécies, havendo grande produção de hidrocarbonetos, alcoóis, cetonas ou monoterpenos dependendo da espécie. Apocynaceae apresenta uma alta diversidade morfológica e metabólica em seus osmóforos que não pode ser correlacionada à morfologia, organização subcelular, período de liberação da secreção ou síndrome de polinização. Esse é o primeiro estudo estrutural abrangente sobre osmóforos na família e aponta para processos evolutivos muito distintos que podem estar relacionados a múltiplos surgimentos na filogenia e associações espécie-específicas com os polinizadores
85

Researches of H2S generation from municipal landfills and systematical evaluation of landfills pollution / Komunalinių atliekų sąvartynuose išsiskiriančio H2S tyrimai ir sąvartynų taršos sisteminis įvertinimas

Kazlauskas, Dainius 14 June 2005 (has links)
In Lithuania the amount of waste generation is increasing every year. According to national strategy, all wastes should be disposed in new regional landfills. Landfills pollutes environment with leachate and landfill gas and odours. Landfill gas consists of odorous compounds and one of them is hydrogen sulphide (H2S). Hydrogen sulphide is highly toxic and affects the nervous system with low threshold. As the landfill gas and leachate generation was word widely investigated before this work, it is not necessary to provide new researches on them. The measurements of H2S generation were provided in Jerubaiciai landfill. For the measurements was used “site-on” measurement method, measurements were provided with equipment GD/MG 7, in 51 measurement points and 2 monitoring wells, during different seasons of the year. Results of the measurement shows, that amount of H2S varies in different areas of landfill and during different seasons. The results of dispersion modeling achieved with dispersion model AERMOD, provided under calm weather conditions and under wind dominated in that session winter speed and direction, during different seasons of the year shows, that H2S spreads from landfill in longest distances from landfill’s section during summer (almost in distance equal to 2.5 km the H2S concentration is higher then Highest Allowable Concentration ). In autumn and spring this distance is equal to 1.5 km, and in winter – 800 m. / Susidarančių komunalinių atliekų kiekis Lietuvoje kiekvienais metais didėja. Pagal nacionalinę strategiją, visos komunalinės atliekos Turi būti deponuojamos regioniniuose sąvartynuose, kurie teršia aplinka filtratu iš sąvartyno išsiskiriančiomis dujomis bei kvapais, kurių veina iš sudedamųjų dalių yra sieros vandenilis (H2S). H2S matavimai buvo atlikti Jerubaičių sąvartyne. Iš sąvartyno išsiskiriantis H2S kiekis buvo tiriamas jo išsiskyrimo vietoje, t.y. sąvartyno teritorijoje. Šis matavimo metodas buvo pasirinktas remiantis tuo, kad iš sąvartyno išsiskiriančios taršos dydis ir poveikis priklauso nuo daugelio aplinkos faktorių. Matavimai, naudojant prietaisą GD/MG 7, buvo atlikti 59 matavimo taškuose ir 2 monitoringo šuliniuose, skirtingais metų laikai. Gauti tyrimų rezultatai parodė, kad šios medžiagos kiekis yra skirtingas įvairiose sąvartyno zonose bei įvairiais metų laikais. Norint ištirti H2S sklaidą buvo atliktas skaitmeninis dispersijos modeliavimas naudojant programą AERMOD. Jo metu vienu atveju buvo pasirinktos stabilios meteorologinės sąlygos, o kitu pasirinkti dominuojančios konkrečiu metų laiku vėjo kryptys ir greičiai. Modeliavimo rezultatai parodė, kad vasarą H2S didžiausia leistina koncentracija pasiekiama tik maždaug 2,5 kilometrų, rudenį ir pavasarį 1,5 kilometrų, o žiemą - už 800 metrų atstumu nuo sąvartyno teritorijos.
86

The artificially scented ape : investigating the role of fragrances and body odours in human interactions

Allen, Caroline January 2015 (has links)
It was long believed that humans were unable to utilise the odours of conspecifics to co-ordinate social interactions in ways in which other species appear to be capable. However, a surge in interest in human social olfaction has recently challenged this view. The numerous studies conducted in this area have found that multiple state and trait related cues can be detected in body odour. Furthermore, many studies indicate that women are often more sensitive to these cues, and that sensitivity can be associated with fertility, findings that are consistent with sex differences in reproductive effort and benefits of choosiness in mate-searching. Since previous studies in this area have usually addressed the potential for humans to use olfactory communication in a comparable manner to other mammals, they typically involve collection and assessment of ‘natural’ odour. That is, they explicitly exclude the possibility of ‘contamination’ of odour samples by artificial fragrances. However, humans have used artificial fragrances for millennia, across many different cultures. This raises the question of whether widespread fragrance use may affect or disrupt the detection of this information in modern humans. The first aim of this thesis was to address this question by investigating how fragrance use may mediate the detection of olfactory information in humans. As well as providing further evidence for sex differences in the assessment of olfactory cues, and for the role of olfaction in real world partner choice, the findings herein suggest that fragrance may act differently on different information being assessed, potentially masking accurate assessment of certain traits (such as masculinity), while fragrance choice and preferences may be important in complementing other olfactory information (such as the general distinguishability of an individuals’ odour profile). A second aim of the thesis was to develop a scale in order to more accurately describe the varying perceptual qualities of human body odour – in other words to map human body odours. This work was conducted alongside perfumers in order to benefit from their expertise in olfactory perception and semantic labelling of odours. The development of such a scale could enable improved understanding of the perceptual qualities of human odour, making it possible to link specific perceptual qualities to specific cues (e.g. symmetry, masculinity, sex) or to manipulate odours based on perceptual qualities in experimental settings, and has direct practical implications for fragrance designers and for improving the ability of individuals to choose fragrance products that suit their odour profile. The second section of the thesis focuses on the effects of odours on the individual wearer as well as on perceivers in the environment. One study is presented which investigates the role of malodour reduction compared to the addition of fragrances in perceptions of confidence and attractiveness, finding that both the reduction of malodour and the addition of fragrance appear to be important for confidence as rated by others in the environment. The final study presented in the thesis examines a hitherto un-investigated role of olfaction during human pregnancy. The rationale for the study is based on evidence suggesting that in certain non-human species, which also show bi-parental care of offspring, there may be a role for chemical, or odour based, communication which underpins behavioural and endocrinological changes related to infant care behaviours in males. The study found little evidence to support the presence of analogous olfactory signalling during human pregnancy, though the findings are discussed in light of methodological changes which, if made in future studies, may result in different outcomes. The thesis concludes with a discussion of the importance of continuing to investigate various forms of olfactory communication, as well as improving our understanding of odours through the mapping of their perceptual qualities, and finally further examining the ways in which various fragranced products, which are widely used in society, may affect all of this. Future directions for this area of research are discussed. This line of investigation will, I argue, enable us to finally establish the true role of olfaction in contemporary social environments.
87

Vyhledávání výbušnin a nástražných výbušných systémů pomocí psů / Explosive substances and traps searching by the help of dogs

HONČÍK, Václav January 2010 (has links)
The one of the dog use scope is explosive substances and booby traps searching. At present, when very often terrorist attacks or threats appear this usage is more and more often. To use the dog for this purpose means the dog has to be trained by means of complex training. In my thesis I have described the basic dog training and another training focused to special activities as the searching of explosive materials and mines is. I did not describe the all dogs basic exercises which the dog must handle safely because this theme is very extensive but only such excercise which I consider as important for explosive materials searching in practises. I have used available literature about dogs training and excercise, expert editorials and guidelines, my own experience with police dogs training and skilled knowledge from workshops and seminar meetings. I have created complex overview the dog preparing and the way of dog training for this special use. I have compared some methods for dogs training and way of excercise used in USA. By means of dogs special training and by means of their use we prevent extraordinary events and we preserve the human life doubtless. The thesis corresponds with another authors similar theses.
88

Odour sensing by insect olfactory receptor neurons: measurements of odours based on action potential analysis

Huotari, M. (Matti) 23 November 2004 (has links)
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).
89

Výběr partnera na základě čichového imprinting-like efektu / Mate choice based on olfactory imprinting-like effect

Kuncová, Lucie January 2018 (has links)
Previous studies have shown that women choose partners resembling their fathers in various characteristics. However, none of the studies have focused on woman's father-partner body odour similarity, even though body odour plays an important role in mate choice. The main aim of our study was to test whether the woman's father and partner body odour is similar and whether the rating of this similarity was affected by the body odour's intensity and pleasantness. Further, we wanted to know whether the quality of woman's relationship with her father during her childhood influences the body odour similarity. We also tested the effect of woman's father-partner body odour similarity on sexual and relationship satisfaction. Twenty-five women with their fathers and partners participated in the study. Every respondent completed a set of questionnaires, in addition, fathers and partners provided samples of their body odours. Body odour similarity was rated by independent female raters (N=128). According to the results of our study, body odour of woman's father and partner is significantly similar. The body odour was also similar in intensity and pleasantness. The quality of woman's relationship with her father does not affect woman's father-partner body odour similarity. Nevertheless, this similarity...
90

Efekt kalorického příjmu a aromatických látek na kvalitu lidské tělesné vůně / The effect of caloric intake and aromatic substances on the human body odour quality

Fialová, Jitka January 2012 (has links)
Previous work has shown that mate choice is in part affected by cues associated with quality and condition of potential mate. These cues could be based on visual characteristics or as shown recently on chemical cues. There is growing evidence which suggest that body odour plays relatively significant role in mate choice. Moreover, body odour is to some extent affected by ingested diet. Therefore, we focused on the effect of caloric restriction and garlic consumption on axilary odour. Our results suggest that restoration of food intake improve body odour in terms of pleasantness and attractiveness (probably as a consequence of recommended specific diet), but during caloric restriction it is rated lower. The garlic consumption improves hedonic assessment of body odour. This effect could be ascribed to his well-known health effects. Our findings thus confirm assumption that ingested diet affects body odour and these changes in odour attractiveness could serve as a cue to individual condition and quality.

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