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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

Avaliação toxicogenética e ecotoxicológica de corantes têxteis / Toxicogenetic and ecotoxicological assessment of textile dyes

Gisele Augusto Rodrigues de Oliveira 12 June 2013 (has links)
O tingimento de tecidos começou há milhares de anos e a disponibilidade comercial de corantes é enorme e crescente. A indústria têxtil brasileira desempenha um papel de inquestionável importância, destacando-se entre as principais atividades econômicas do país. O processo de tingimento é um dos fatores fundamentais no sucesso comercial dos produtos têxteis, uma vez que o consumidor exige cores resistentes à exposição ao calor, à luz, à transpiração e às lavagens. Segundo a literatura, condições de transpiração intensa contribuem para uma alta taxa de migração e subseqüente penetração de corantes têxteis para a pele humana. Além disso, 2 a 50% desses compostos permanecem no banho de tingimento e são descartados nos efluentes industriais, contaminando o ambiente e colocando em risco a saúde humana, uma vez que os métodos convencionais de tratamento de efluentes são ineficientes na remoção da coloração e da mutagenicidade de alguns corantes. Dentro deste contexto, este trabalho teve como objetivo avaliar os efeitos toxicogenéticos do corante Direct Black (DB38) original e após extração por lixiviação com suor sintético, utilizando o teste do cometa com fibroblastos e queratinócitos de pele humana, o teste Anexina V com fibroblastos e o ensaio de mutagenicidade com Salmonella typhimurium. Adicionalmente, foi investigada a ecotoxicidade dos corantes têxteis Direct Black 38 e Reactive Blue 15 (RB15) originais por meio de ensaios com sementes, dapnhias, minhocas e zebrafish realizados na UTOX, em Barcelona. O corante DB38 original e lixiviado não induziram genotoxicidade em fibroblastos e queratinócitos de pele humana. O corante DB38 original foi mutagênico para as linhagens TA98 e TA100 de S. typhimurium na presença de S9. Entretanto, o corante lixiviado não induziu mutagenicidade para essas linhagens testadas, considerando que a maior taxa de migração do corante para a solução de suor foi de ~1% nas seguintes condições: tingimento sem ensaboamento, pH 8,0 e 8 horas de incubação à 42°C. O corante original é citotóxico para fibroblastos após 48 horas de exposição. No entanto, essa citotoxicidade não foi mais observada após a lixiviação no suor. Os corantes DB38 e RB15 originais não foram tóxicos para as sementes de pepino, alface e tomate, e nem para as minhocas Eisenia foetida. Ambos os corantes foram fracamente tóxicos para Daphnia magna, porém o RB15 apresenta maior potencial tóxico em relação ao DB38. Os corantes DB38 e RB15 induziram malformações em larvas de zebrafish Danio rerio, caracterizadas por falha na inflação da bexiga natatória e alteração na cauda. Portanto, nossos resultados mostram a importância de se fazer não só a análise individual de corantes têxteis, mas também dos tecidos que os contêm. Além da necessidade de se desenvolver técnicas de tingimento mais seguras em relação à solidez da cor sob condições úmidas e as perdas de corante para o ambiente durante a etapa de fixação, indicando maior atenção ao estudo de efeitos sub-letais na avaliação do impacto desses compostos no ecossistema aquático. / The fabrics dyeing began thousands of years ago and the commercial availability of dyes is increasingly. The Brazilian textile industry plays a role of high importance, highlighting among the main economic activities in the country. The dyeing process is one of the key factors in the commercial success of textile products, since consumers are demanding colors more resistant to heat, light exposure, perspiration and washing. According to the literature, conditions of intense perspiration contribute to the migration and subsequent penetration of textile dyes to human skin. Furthermore, 2 to 50% of the initial dye load is present in the dye bath effluent and these compounds are discharged in industrial effluents, contaminating the environment and endangering human health, since the wastewater treatment systems are ineffective in removing the color and mutagenicity of some dyes. In this context, this study aimed to evaluate the toxicogenetic effects of the Direct Black 38 (DB38) dye original and extracted by leaching with artificial sweat using Comet assay with fibroblasts and keratinocytes from human skin, Anexin V assay with fibroblasts and Salmonella mutagenicity test. Additionally, we investigated the ecotoxicity of textile dye Direct Black 38 and Reactive Blue 15 (RB15) using assays with seeds, dapnhias, worms and zebrafish performed in UTOX in Barcelona. The original and leached DB38 dye did not induce genotoxicity in fibroblasts and keratinocytes from human skin. The original DB38 was mutagenic for TA98 and TA100 of S. typhimurium with S9. However, the solution with the leached dye did not induce mutagenicity for these tested strains, since the highest migration rate of the dye to the solution of artificial sweat was ~ 1% in the following conditions: type of dyeing without rinsing, pH 8.0 and 8-hour incubation at 42°C. The original dye was cytotoxic for fibroblasts after 48 hours of exposure. However, this cytotoxicity was no longer observed after leaching in sweat. The original DB38 and RB15 dyes showed no toxicity for cucumber, lettuce and tomato seeds and for earthworms Eisenia foetida. Both dyes were weakly toxic for Daphnia magna, but the RB15 has a higher toxic potential compared to DB38. The dyes DB38 and RB15 induced malformations in larvae of zebrafish Danio rerio by failure of the swim bladder inflation and changes in the tail. Therefore, our results show the importance of making the individual analysis of textile dyes, but also of fabrics containing them. Furthermore, it is necessary to develop safer techniques of dyeing in relation to the color fastness under humid conditions and the loss of dyes into the environment during the fixation step, indicating more attention to the study of sub-lethal effects in the evaluation of the impact of these compounds in the aquatic ecosystem.
82

Altered Olfactory Processing of Stress Related Body Odors and Artificial Odors in Patients with Panic Disorder

Wintermann, Gloria-Beatrice, Donix, Markus, Joraschky, Peter, Gerber, Johannes, Petrowski, Katja 06 February 2014 (has links)
Background: Patients with Panic Disorder (PD) direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD. Methods: A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry) as well as artificial odors (peach, artificial sweat) as non-fearful non-body odors. Principal Findings: The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology. Conclusions: The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the psychopathology.
83

Electroanalytical devices with fluidic control using textile materials and methods

Öberg Månsson, Ingrid January 2020 (has links)
This thesis, written by Ingrid Öberg Månsson at KTH Royal Institute of Technology and entitled “Electroanalytical devices with fluidic control using textile materials and methods”, presents experimental studies on the development of textile based electronic devices and biosensors. One of the reasons why this is of interest is the growing demand for integrated smart products for wearable health monitoring or energy harvesting. To enable such products, new interdisciplinary fields arise combining traditional textile technology and electronics. Textile based devices have garnered much interest in recent years due to their innate ability to incorporate function directly into, for example, clothing or bandages by textile processes such as weaving, knitting or stitching. However, many modifications of yarns required for such applications are not available on an industrial scale. The major objective of this work has been to study how to achieve the performance necessary to create electronic textile devices by either coating yarns with conductive material or using commercially available conductive yarns that are functionalized to create sensing elements. Further, liquid transport within textile materials has been studied to be able to control the contact area between electrolyte and electrodes in electrochemical devices such as sensors and transistors. Yarns with specially designed cross-sections, traditionally used in sportswear to wick sweat away from the body and enhance evaporation, was used to transport electrolyte liquids to come in contact with yarn electrodes. The defined area of the junction where the fluidic yarn meets the conductive yarn was shown to increase stability of the measurements and the reproducibility between devices. The results presented in the two publications of this thesis as well as additional results presented in the thesis itself show the promising potential of using textile materials to integrate electronic and electrochemical functionality in our everyday life. This is shown by using basic textile materials and processing techniques to fabricate complex devices for various application areas such as sensors and diagnostics as well as electrical and energy harvesting components. / Denna avhandling, skriven av Ingrid Öberg Månsson vid Kungliga Tekniska Högskolan och titulerad ”Elektroanalytiska sensorer med vätskekontroll integrerad genom användande av textila material och metoder”, presenterar experimentella studier inom utvecklingen av textilbaserade elektroniska komponenter och biosensorer. Detta är av intresse på grund av den ökade efterfrågan på integrerade smarta produkter som till exempel bärbara sensorer för hälsoövervakning eller för att samla upp och konvertera energi till elektricitet. För att möjliggöra denna typ av produkter föds nya interdisciplinära fält där traditionell textilteknologi och elektronik möts. Textilbaserade enheter har väckt stort intresse under de senaste åren på grund av den naturliga förmågan att integrera funktion i till exempel kläder eller förband genom textila tillverkningsprocesser som väveri, stickning eller sömnad. Många modifikationer hos garner som krävs för att möjliggöra sådana tillämpningar är dock inte tillgängliga i större skala. Därför har det huvudsakliga syftet med denna studie varit att undersöka hur man kan uppnå den prestanda som krävs för att tillverka elektroniska textila komponenter, antingen genom att belägga garner med elektroniskt ledande material eller genom att använda kommersiellt tillgängliga ledande garner som sedan modifieras kemiskt för att skapa sensorer. Utöver detta har vätsketransport inom textila material studerats för att kunna styra och kontrollera kontaktytan mellan elektrolyt och elektroder i elektrokemiska enheter så som sensorer och transistorer. Garner med speciella tvärsnitt, som traditionellt använts i sportkläder för att transportera svett bort från kroppen och underlätta avdunstning, har använts för att transportera elektrolytvätska till elektroder av garn. Den definierade kontaktytan där det vätsketransporterade garnet korsar elektrodgarnet har visats öka stabiliteten av mätningen och reproducerbarheten mellan mätenheter. Resultaten som presenteras i de två artiklar som denna avhandling bygger på samt i avhandlingen själv visar på lovande potential för användandet av textila material för att integrera elektronisk och elektrokemisk funktionalitet i våra vardagsliv. Detta har uppnåtts genom att använda grundläggande textila material och tillverkningsprocesser för att tillverka komplexa enheter för olika tillämpningsområden så som sensorer för diagnostik samt elektroniska komponenter. / <p>QC 2020-08-21</p>
84

LactateStat: Wearable Electronics and Software for Real-Time Lactate Monitoring in Sweat / LactateStat: Bärbar elektronik och mjukvara för realtidsövervakning av laktat i svett

Ekelund, Emil January 2021 (has links)
Lactate is an important biomarker in sports and the lactate threshold concept is one of the best indicators of endurance performance in an athlete. However, to quantify the lactate threshold, an invasive method to take a blood sample must be used. Limitations for this method include stopping the active exercise for blood sampling and no real-time feedback. Instead, a novel non-invasive wearable biosensor can be used to measure the lactate concentration in sweat. The sensor generates an electrical current depending on the lactate concentration in the sweat, and therefore must an electronic device called a potentiostat be used to condition the current. However, available potentiostats are not suitable for use in sports where form factor, battery life and wireless connectivity is important. This thesis aims to solve this by developing a wearable device and software which can be used to measure the lactate concentration in sweat in real-time during exercise. The development process consisted of the determination of specifications, prototype development and thorough laboratory and on-body testing. Finally, a novel wearable device and software capable of real-time lactate measurements in sweat during exercise were presented. The device, called LactateStat, was 58mm ∗ 55mm ∗ 13mm, the current consumption was only 7.8mA, the current measurement resolution was 0.5 nA, the limit of detection was 0.45 nA and the current measurement range was around 750 μA. LactateStat is one of the first of its kind and provides a base for future development as the hardware, firmware and software resources are provided as open-source. / Laktat är en viktig biomarkör inom idrott och konceptet laktattröskel är en av de bästa indikatorerna för uthållighet hos en idrottsutövare. Men för att mäta laktattröskeln krävs en invasiv metod som går ut på att man tar ett blodprov. Begränsningarna med denna metod är bland annat att idrottsutövningen måste stoppas för att ta ett blodprov och att man inte får realtidsåterkoppling. I stället kan en liten och icke-invasiv bärbar biosensor användas för att mäta laktatkoncentrationen i svett. Sensorn genererar en elektrisk ström beroende på laktatkoncentrationen i svetten och en enhet som kallas potentiostat måste därför användas för att mäta denna ström. Tillgängliga potentiostater är dock inte lämpliga för användning inom sport där formfaktor, batteritid och trådlös kommunikation är viktigt. Denna avhandling har som syfte att lösa detta genom att utveckla en bärbar enhet och mjukvara som kan användas för att mäta laktatkoncentrationen i svett i realtid under träning. Utvecklingsprocessen bestod av bestämning av specifikationer, framtagning av en prototyp och noggrann laboratorie- och kroppstestning. Som resultat presenterades en banbrytande bärbar enhet och mjukvara som kan mäta laktat i realtid i svett under träning. Enheten, som kallades LactateStat, var 58mm * 55mm * 13mm, den aktiva strömförbrukningen var 7.8mA, den bästa mätupplösningen för ström var 0.5 nA, detektionsgränsen var 0.45 nA och det maximala mätområdet för ström var ca. 750 μA. LactateStat är en av de första i sitt slag och ger en bas för framtida utvecklingsarbete eftersom hårdvaru-, programvaru- och mjukvaruresurserna tillhandahålls som öppen källkod.
85

Discovery of Nanostructured Material Properties for Advanced Sensing Platforms

Wujcik, Evan K. 28 August 2013 (has links)
No description available.
86

Sex workers as free agents and as victims : elucidating the life worlds of female sex workers and the discursive patterns that shape public understanding of their work

Mbatha, Khonzanani 01 1900 (has links)
In South Africa and many other countries worldwide, sex work is criminalised. This invariably seems to lead to back-door prostitution - an unregulated industry where sex workers are vulnerable to being exploited by pimps, brothel owners and law enforcement officers. In discussions about sex work and sex workers, two dominant views are evident: a) Sex workers freely choose to sell sex as a good way of earning an income; or b) sex workers are victims of their circumstances who are driven into the industry through direct coercion or as a result of dire poverty. Together, these views lead to an ideological trap in terms of which sex workers have to be perceived either as having agency and free will or as being helpless victims in need of rescue. My aim in this thesis was to problematise, deconstruct and reconstruct the discursive field within which sex work is embedded, in order to move beyond agency-victimhood and similar binaries, and in the hope of developing new ways of talking about prostitution that acknowledge the complexity of the sex industry rather than shoehorning it into preconceived categories. Social constructionism (epistemology), critical social theory (ontology) and discourse analysis (methodology) were interwoven in order to provide a broad, critical understanding of prostitution. Two data sources were used to gain access to and unpack the life worlds of sex workers: Semi-structured interviews with five sex workers in Johannesburg and the “Project 107” report on adult prostitution in South Africa. Foucauldian discourse analysis was used to make sense of the data, including an analysis of how concepts such as governmentality, power, confession, surveillance and technologies of the self can be applied to contemporary texts about prostitution. The “Project 107” report recommended that prostitution should not be decriminalised, and that sex work should in fact not be classified as work; instead, it proposed a ‘diversion programme’ to help sex workers exit the industry. I show how, in doing this, the report appears to hijack feminist discourses about sex workers as victims in order to further a conservative moral agenda. The sex workers I spoke to, on the other hand, demonstrated an ability to take on board, and to challenge, a variety of different discourses in order to talk about themselves as simultaneously agentic and constrained in what they can do by unjust social structures. I show how, from a Foucauldian perspective, sex workers can be seen not as pinned down at the bottom of a pyramid of power, but immersed in a network of power and knowledge, enabled and constrained by ‘technologies of the self’ to assist in policing themselves through self-discipline and self-surveillance to become suitably docile bodies within the greater public order. / Psychology / D. Litt. et Phil. (Psychology)
87

Metal Particles – Hazard or Risk? Elaboration and Implementation of a Research Strategy from a Surface and Corrosion Perspective

Midander, Klara January 2009 (has links)
Do metal particles (including particles of pure metals, alloys, metal oxides and compounds) pose a hazard or risk to human health? In the light of this question, this thesis summarizes results from research conducted on metal particles, and describes the elaboration and implementation of an in vitro test methodology to study metal release from particles through corrosion and dissolution processes in synthetic biological media relevant for human exposure through inhalation/ingestion and dermal contact. Bioaccessible metals are defined as the pool of released metals from particles that potentially could be made available for absorption by humans or other organisms. Studies of bioaccessible metals from different metal particles within this thesis have shown that the metal release process is influenced by material properties, particle specific properties, size distribution, surface area and morphology, as well as the chemistry of synthetic biological test media simulating various human exposure scenarios. The presence of metal particles in proximity to humans and the fact that metals can be released from particles to a varying extent is the hazard referred to in the title. The bioavailable metal fraction of the released metals (the fraction available for uptake/absorption by humans through different exposure routes) is usually significantly smaller than the bioaccessible pool of released metals, and is largely related to the chemical form and state of oxidation of the released metals. Chemical speciation measurements of released chromium for instance revealed chromium to be complexed to its non-available form in simulated lung fluids. Such measurements provide an indirect measure of the potential risk for adverse health effects, when performed at relevant experimental conditions. A more direct way to assess risks is to conduct toxicological in-vitro testing of metal particles, for instance on lung cell cultures relevant for human inhalation. Induced toxicity of metal particles on lung cells includes both the effect of the particles themselves and of the released metal fraction (including bioaccessible and bioavailable metals), the latter shown to be less predominant. The toxic response was clearly influenced by various experimental conditions such as sonication treatment of particles and the presence of serum proteins. Thorough characterization of metal particles assessing parameters including chemical surface composition, degree of agglomeration in solution, size distribution, surface area and morphology was performed and discussed in relation to generated results of bioaccessibility, bioavailability and induced toxicity. One important conclusion was that neither the surface composition nor the bulk composition can be used to assess the extent of metals released from chromium-based alloy particles. These findings emphasize that information on physical-chemical properties and surface characteristics of particles is essential for an in-depth understanding of metal release processes and for further use and interpretation of bioaccessibility data to assess hazard and reduce any risks induced by human exposure to metal particles. / QC 20100803
88

Etude de la production et de l'émanation de composés volatils malodorants sur textile à usage sportif / Production and emission of human body odors from textile for sports

Léal, Françoise 04 November 2011 (has links)
Si la sueur fraîchement émise par le corps humain est inodore, la dégradation de celle-ci par la flore bactérienne cutanée produit des composés volatils malodorants, responsables des odeurs de transpiration. Les odeurs de transpiration apparaissent également sur les vêtements au cours de leur utilisation, particulièrement sur les textiles réalisés en fibres synthétiques. Ce travail a pour but d’améliorer la compréhension du phénomène d’émanation d’odeurs en étudiant l’effet du sujet testé, l’effet de la flore bactérienne et l’effet du textile sur les émissions de composés volatils malodorants.L’intérêt de ce travail réside dans l’approche globale de la problématique des odeurs de transpiration et dans la diversité des méthodes de mesure mises en place, tant dans l’étude de la flore microbiologique que dans les méthodes de mesures des composés odorants émis.Dans un premier temps, le dénombrement simultané de la flore bactérienne sur la peau et sur le vêtement a été réalisé sur un échantillon de 15 sujets à l’issue d’un exercice physique. Cette expérimentation a permis d’évaluer le taux de transfert bactérien moyen lors d’une activité sportive et d’étudier son rôle dans l’émission d’odeurs. Ensuite, afin d’affiner ces résultats, une méthode basée sur la biologie moléculaire a été mise en place pour réaliser le suivi qualitatif de la stabilité de la flore commensale axillaire d’un sujet pendant 3 mois. Le transfert bactérien spécifique entre la peau du testeur et le vêtement a été étudié pour 4 matières textiles sélectionnées (dont le coton et le PET). Ceci a permis de déterminer le rôle du transfert bactérien spécifique dans l’émission des odeurs à partir de textile.Enfin, le dernier chapitre est consacré à l’étude de l’émission de composés volatils et odorants à l’aide de mesures olfactives et d’un nez électronique au cours du temps par 8 composants textiles sélectionnés. Après traitement statistique par analyse en composante principale et étude détaillée des mesures, 9 composés chimiques ont été identifiés comme indicateurs d’un comportement textile malodorant. Ces derniers pourraient être utilisés dans la mise en place d’une méthode ciblée de mesure physico-chimique des mauvaises odeurs.Ce travail a permis de déterminer l’impact de chacun des facteurs sujet, flore bactérienne et textile dans l’émission d’odeurs. En outre, ce travail ouvre des perspectives sur l’étude des contaminations bactériennes par contact, mais également dans l’étude des odeurs, sur les phénomènes de désorption de molécules volatiles à partir de différentes matrices textiles et sur les solutions pouvant être envisagées pour limiter les émissions odorantes à partir de textiles. / Fresh human sweat is odorless. Odoriferous volatile compounds are produced by the metabolism of bacteria living on the skin, generating strong malodor. Sweaty body odors do also appear on clothes during use, and especially on synthetic fabrics. The aim of this document is to improve understanding of odor emission by investigating subject effect, microbiota effect and fabric effect on the emission of odoriferous volatile compounds.Odors of perspiration are hereby globally approached with a wide use of methods and experimental devices, for microbial flora study as well as for odoriferous volatile compounds emission study.First, microflora enumeration has been simultaneously processed on the skin and on the fabric after exercise for 15 subjects. This experiment allowed an evaluation of the average bacterial transfer yield during physical activity and the beginning of the investigation of its effect on odor emission.A molecular biology methodology has then been developed in order to refine these results. Monitoring of qualitative composition of the microbiota has been performed to study the stability of the armpit’s ecosystem on a subject during 3 months. Specific microbial transfer from subject’s skin to clothe has been performed for 4 textile fabrics (including cotton and PET). This leaded to characterize the effect of specific bacterial transfer on odor emission from fabric.The last chapter is dedicated to the study of the emission of odoriferous volatile compounds over time using olfactory measurements and electronic nose for 8 selected fabrics. Principal component analysis targeted 9 chemical compounds that have been selected as malodorous behavior indicators for a given fabric. Those 9 compounds could be used for setting up a fitted physicochemical method of malodor.To conclude, this study helped to understand the effect of 3 factors in odor perception from a fabric after sport : subject, microbial flora and fabric. Perspectives have been charted on contact microbial contamination, but also on odor, and especially on desorption of odoriferous volatile molecules from a textile or knitted matrix. The solutions that could be used to limit malodorous emission from fabrics have also been discussed.

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