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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.
51

Influência do grau de etoxilação no comportamento de álcoois secunários etoxilados / The influence of ethoxylation degree in the behaviour of secondary alcohol ethoxylates

André Bozzo Argenton 24 April 2009 (has links)
A solubilização de solutos não iônicos através de um processo de partição entre água e a pseudo-fase micelar de tensoativos não iônicos foi estudada para álcoois secundários etoxilados com grau de etoxilação variando entre 7 e 40. Mostrou-se que o coeficiente de incorporação micelar, Ks, é independente do grau de etoxilação o que corrobora a hipótese de que a partição ocorre entre água e o núcleo hidrocarbônico da micela, que não é alterado pelo aumento do número de grupos de óxido de eteno na cabeça polar do tensoativo. O uso de relações lineares de energia livre, LSER, para a predição da capacidade de solubilização de álcoois secundários etoxilados forneceu, através de regressão múltipla linear a seguinte LSER como melhor modelo: log Ks = -0,42 + 1,21E - 1,73S -0,40A - 1,13B + 3,01V com R2 = 0,98 e valor de teste F de 1390. Nesta equação, V é o volume molar do soluto, A e B são a capacidade do soluto de atuar como doador e aceptor de pontes de hidrogênio, E é a refração molar em excesso e S representa a capacidade do soluto de interagir com o meio de solubilização através de interações do tipo dipolo-dipolo e dipolo-dipolo induzido. Mostrou-se que processos de limpeza aplicados à remoção de sujidades de tecidos e superfícies sólidas não estão correlacionados ao mecanismo de solubilização descrito por um processo de partição. A dependência da redução de tensão interfacial com o grau de etoxilação sugere que a eficiência de limpeza, para superfícies sólidas e para tecidos, está correlacionada de maneira direta, mas não linear, com a capacidade do tensoativo de concentrar-se na interface \"sujidade-solução aquosa de tensoativo\" reduzindo assim a tensão interfacial entre os dois meios. / The solubilization of non-ionic solutes via partitioning between water and the micellar pseudophase of non-ionic surfactants was evaluated for a series of secondary alcohol ethoxylates with hydrophile length varying from 7 to 40 ethylene oxide units. It was demonstrated that the micellar incorporation constant, Ks, is not dependent on the hydrophile length of the surfactant. The results obtained in this study support the hypothesis that the partitioning between water and the micellar core is not disturbed by the etheylene oxide hydrophilic groups. Linear solvation free energy relationships, LSER, were used to model the ability of the surfactants to solubilize non-ionic compounds. Multiple linear regression analysis provided the following LSER with R2 of 0.98 and F value of 1390: logK = -0,42 + 1,21E - 1,73S - 0,40A - 1,13B + 3,01V. In this LSER, V is a descriptor of solute molar volume, A and B capture the overall ability of the solute to act as a hydrogen bond donor and acceptor, E is the solute excess molar refraction and S is a descriptor of the ability of the solute to interact via dipole-dipole and dipole-induced dipole interactions with its surroundings. It was demonstrated that hard and soft surface cleaning efficiencies are not correlated with the solubilization process. It was shown, however, that the change in interfacial tension caused by the change in the hydrophile portion of the surfactants has a direct, but non-linear impact on the cleaing properties of aqueous solutions containing these surfactants.
52

Estudio de pre factibilidad para la instalación de una planta productora de detergente líquido

Conroy-Morel, Gonzalo, Sánchez-Proaño, Ingrid-Gennevive January 2015 (has links)
La investigación busca aplicar los conceptos de ingeniería industrial, a través de la realización de un producto que hace más fácil un proceso cotidiano, como el lavado de la ropa. / The project also seeks, like all business, to generate returns to investors over 5 years posed as the duration. / Trabajo de investigación
53

Studying Transmembrane Helix Interactions in SDS micelles

Qureshi, Tabussom January 2016 (has links)
The importance of interactions between transmembrane domains of integral membrane proteins has been well-established in a range of essential cellular functions. Most integral membrane proteins also possess regions that lie on the exterior of the membrane that may influence the ability of these transmembrane domains to interact. We sought to test this hypothesis by quantifying the energetics of transmembrane helix self-association in the absence and presence of an amphipathic helix that can bind to the membrane surface. The model chosen for this study was the major coat protein (MCP) of M13 bacteriophage, which has an N-terminal amphipathic helix linked to its single transmembrane segment via a flexible linker. Dimerization of both full-length MCP and a peptide containing only the transmembrane domain (MCPTM) was studied by solution NMR in SDS micelles. We found that there was an increase in the apparent dimerization affinity in the absence of the N-terminal helix. However, this increase in apparent affinity could be attributed to differences in detergent-binding properties of the two polypeptides in monomeric versus dimeric states when the empty micelle was considered to be a participant in the dimer dissociation. Preliminary results from the integral membrane protein, p7 of the hepatitis C virus are also presented in this thesis. It has been demonstrated that p7 enhances viral infectivity and accumulation, and that this function may require oligomerization in the membrane. While we encountered limitations due to challenges in the generation of sufficient quantities of pure p7 samples, we were able to perform circular dichroism spectroscopy under conditions that may favor different oligomeric states. These studies suggest that there is a change in the degree of helicity upon oligomerization, and suggest that SDS could be a suitable system to characterize the interactions of the p7 oligomer in the future.
54

Segmentation of washing detergents in the Czech Republic / Segmentace trhu pracích prostředků v České republice

Pejlová, Gabriela January 2012 (has links)
The master thesis is devoted to the explanation of the theory of market segmentation and then its application on the washing detergents market in the Czech Republic. The goal is to describe trends in segmentation of washing detergents and suggest possible reasons for them. Thus, the thesis is a combination of three parts -- the first depicts the theory in question, the second part captures empirical data of the washing detergents market describing the aggregate market and its individual segments in detail, and the third and final part is devoted to an attitude of customers to washing detergents in the Czech Republic.
55

Analýza trhu pracích prostředků a značky Perwoll na českém trhu / Detergents market analysis and Perwoll brand analysis on the Czech market

Bravená, Martina January 2011 (has links)
The aim of the Master`s Thesis is analysis of detergents market on the Czech market with focus on Perwoll brand and prove or disprove the previously stated hypothesis together with the aid of the primary and secondary data from marketing research. After that it was proposed the recommendation for other brand marketing orientation. Under the terms of the analysis the thesis is looking into the consumer behaviour on the detergents market and its structure. The thesis is structured into three main parts. First part is theoretical and creates a background for the other parts. Second part primarily describes the detergents market, the structure and consumer perception. What is the brand awareness and what is the key factor during the buying decision process. Later on, it is looking into the Perwoll brand itself and its characteristics. The last part is the marketing research based on primary data and questionnaire research. In the end, the results of the research are summarized and potential solutions are made.
56

Sustainablility message appeals and deception in cleaning products : A study on trust of Emotional vs Rational sustainability appeals

Sbrogio, Alice, Shamon, Kristian January 2023 (has links)
In an increasingly environmentally conscious world, the creation of sustainable communication and marketing becomes crucial. Generally, young consumers are environmentally conscious and seek sustainable products while remaining wary of greenwashing and deceptive claims. However, they are likely to be heavily influenced by social media and peers, which makes them a receptive target for advertisers’ deceptive strategies. To achieve success, advertisements must be trustworthy and appeal to the target audience either emotionally or rationally. Sustainability labels like the EU Eco-label fosters consumer trust. Hence, our research will focus on the impact of sustainability message appeals on deceptiveness in laundry detergents and the influence of certifications in product advertising on customer deceptiveness.The purpose of this study is to examine the impact of sustainability messages on perceived deceptiveness of laundry detergents. Moreover, it explores the relationship between emotional and rational appeals and consumer behaviour, with a focus on trust, deceptiveness and purchasing intentions. Accordingly, the study was conducted on consumers to see how theyperceive emotional and rational advertisement. The findings will guide managers and entrepreneurs to effectively market cleaning products for enhanced sustainability perception and transparency. The study has employed a deductive approach, utilising a quantitative research design. Data was collected through a survey from 299 participants, aged 18-30, representing diverse European backgrounds. The collected data was analysed by using a moderated mediation approach, allowing for a comprehensive examination of the relationships between sustainability message appeals, deceptiveness, and the influence of certifications in product advertising. The research showed that consumers may be misled by emotional sustainability appeals in laundry detergent advertising, hence the intention to purchase decreases. Nevertheless, it was revealed that rational appeals and third-party certifications such as EU Ecolabel positively influenced perceived sustainability and purchase intention. The study also found that gender had no significant moderating impact, while sustainability awareness moderated the relationship between deception and purchase intention in emotional appeals.
57

The trafficking and signaling of EGF receptors in hepatocyte rafts /

Wang, Ye, 1975- January 2007 (has links)
No description available.
58

Effects of hydraulic loading and laundry detergent on the operation of aerobic package treatment systems

Hanna, K. Michael 03 March 2009 (has links)
This study focused on three potential problems with the operation of aerobic package treatment systems: hydraulic retention time, laundry detergents, and hydraulic surges. To determine the effect of hydraulic retention time on system performance, six bench scale activated sludge systems were constructed. Wastewater from an actual residence was collected twice per week and fed to the small activated sludge systems. Two of the systems had a hydraulic retention time of 2 days, two had a hydraulic retention time of 1 day and two had a hydraulic retention time of 0.5 days. Effluent quality was stable and good with regard to chemical oxygen demand (COD) and ammonia (NH)-N) and seemed to be independent of hydraulic retention time. All of the systems performed well, despite considerable variability in influent strength. To study the effect of high concentrations of laundry detergents on the operation of package treatment systems, three of the six laboratory systems were fed high concentrations of detergent. Other than some residual COD from the detergent, no effect on system performance was observed. The final component of the study was the modification of an existing package treatment system to equalize flows from an automatic washing machine. After a month of operation the modified system produced a more constant effluent quality, than did the unmodified system. The field system, with and without modification, had a low mixed liquor suspended solids (MLSS) concentration (35 mg/L). This was probably the result of the long hydraulic retention time. As a result of the low MLSS the system, with and without modification, did not meet Virginia effluent requirements for BODs, TSS or D.O. or generally accepted levels of NH₃-N. / Master of Science
59

Vers une méthodologie de la déformulation des mélanges complexes combinant outils analytiques et chimiométriques : apllication aux détergents / Towards a deformulation methodology for complex mixtures combining analytical and chemometric tools : application to detergent products

Gaubert, Alexandra 26 November 2015 (has links)
Que ce soit à des fins de contrôle qualité ou de veille concurentielle, la déformulation (action d'identifier et de quantifier les constituants d'un produit) représente aujourd'hui un véritable challenge analytique dans de nombreux domaines industriels tels que les cosmétiques, la santé, les matériaux... Dans ce contexte, nous nous sommes intéressés aux mélanges complexes que sont les produits détergents tels que les lessives qui représentent un marché en constante croissance et en perpétuelle évolution. Dans ce secteur, en effet, les réglementations sont de plus en plus drastiques et les consommateurs plus exigeants ce qui entraine le développement de nouveaux produits plus respectueux de l'environnement et de la santé intégrant des tensioactifs bio-sourcés et des enzymes. Les lessives pouvant contenir jusqu'à 25 composés différents, nous nous sommes focalisés sur l'analyse de leurs composés majoritaires que sont les tensioactifs et les enzymes. Après avoir élaboré une échantillothèque exhaustive de ces produits, la RMN du proton et la spectrométrie Raman ont été utilisées pour identifier et quantifier les tensioactifs et la spectrométrie de masse des rapports isotopiques (IRMS) pour l'évaluation de leur origine bio-sourcée. Les résultats obtenus ont montré l'intérêt du couplage de la spectroscopie Raman avec des méthodes chimiométriques d'extraction du signal comme l'ICA et la MCR-ALS pour identifier et quantifier les tensioactifs. L'IRMS a permis d'identifier les tensioactifs d'origine bio-sourcée ainsi que le type de plantes (C3 ou C4) utilisé comme matière première pour leur synthèse. Les enzymes utilisées dans la formulation d'une lessive commerciale ont pu être identifiées et quantifiées grâce à l'association d'une méthode de précipitation des protéines avec une analyse par LC-MS/MS. Ces développements analytiques contribuent à la mise en place d'une méthodologie de la déformulation des produits détergents / Deformulation of complex mixtures requires analytical methods for compound identification and quantification. It still represents a real analytical challenge in various industrial fields, such as cosmetics, health, food, materials. In this context, we studied complex mixtures such as detergents and especially, laundry detergents, that represent a constantly growing market. Regulations becoming stricter and consumers requiring more eco-friendly products, manufacturers constantly innove detergent formulations by using bio-based surfactants or enzymes. Laundry detergents containing up to 25 compounds, we focused on the analysis of their major components, i.e. surfactants and enzymes. After developing a comprehensive sample library of such raw materials, 1H NMR and Raman spectrometry were used for surfactant identification and quantification while Isotope Ratio Mass Spectrometry (IRMS) was tested to evaluate their bio-sourced origin. Raman spectrometry combined with chemometric tools such as signal extraction methods was useful for surfactant identification and quantification. Enzymes were identified and quantified using protein precipitation before analyses by LCMS/ MS. All these analytical developments contribute to the establishment of a deformulation strategy for detergent products
60

Segmentace trhu pracích prostředků / Segmentation of the detergent market

Bulantová, Barbora January 2016 (has links)
This Masters Thesis is focused on detergent market in the Czech Republic and its market segmentation. The goal of this thesis is to find differences and similarities between consumers and to uncover the segments which are internally homogeneous and externally heterogeneous, and to suggest a marketing approach for each segment. Theoretical part of this thesis is about theoretical explanation of the market segmentation process, different approaches to segmentation and methods of segmentation. There is also a description of the detergent market in the Czech Republic. The analytical part is focused on segmentation process itself. The segmentation is based on both primary and secondary data. The revealed segments are then described in detail. There is a suggested marketing approach how to effectively address each segment.

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