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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.
21

Estudi de nous agents de solvatació quiral: a,a'-bis(trifluorometil)-9,10-antracendimetanol i altres

Pomares Marco, Marta 05 February 2002 (has links)
El present treball es basa en la síntesi de nous agents de solvatació quiral els quals són més eficients i versàtils que els ja existents en el mercat. Per tal d'assolir aquest objectiu s'han realitzat diverses modificacions a l'estructura dels CSA més habituals, tal i com els comercials alcohol de Pirkle i la 1-(1-naftil)etilamina. Posteriorment s'ha avaluat l'efecte d'aquestes modificacions en front del comportament d'aquests nous agents de solvatació quiral. A partir d'aquest treball s'han pogut establir diversos fets i conclusions. L'alcohol 2,2-dimetil-1-(1-naftil)propanol s'ha sintetitzat i els seus enantiomers s'han resolt però la seva capacitat com a agent de solvatació quiral sembla presentar una capacitat no tan bona com la proporcionada per l'alcohol de Pirkle. El compost a,a'-bis(trifluorometil)-9,10-antracendimetanol ha estat sintetitzat i els seus diastereoisòmers s'han separat eficientment. S'ha demostrat el bon comportament com a CSA en front de diversos soluts racèmics. Aquest alcohol presenta una gran capacitat per induir enantiodiferenciació amb mescles racèmiques, la qual cosa h a permès demostrar un millor comportament si es compara amb els resultats obtinguts a partir de l'alcohol de Pirkle. S'ha determinat l'estequiometria dels complexos d'associació formats, la qual cosa ha permès determinar que en tots els casos estudiats la relació és 1 a 1; encara que l'alcohol presenta a la seva estructura dos grups funcionals. S'ha dut a terme l'estudi de les constants d'equilibri (K). S'ha observat que les constants (K) augmenten en disminuir la temperatura.A més, s'ha estudiat la síntesi per tal d'obtenir l'alcohol (R,R)-a,a'-bis(trifluorometil)-9,10-antracendimetanol de forma enantiopura de forma molt exitosa.Aquest alcohol s'ha utilitzat a com a auxiliar quiral en una reacció de Diels-Alder. S'ha sintetitzat el mono-acrilat d'aquest alcohol i s'ha fet reaccionar amb ciclopentadiè per formar els respectius adductes diastereoisomèrics. El e.d. obtingut és del 70%. És el mateix resultat que quan s'utilitza l'acrilat de l'alcohol de Pirkle.S'ha desenvolupat una metodologia per obtenir el perdeutero-a,a'-bis(trifluorometil)-9,10-antracendimetanol i s'exposen les avantatges d'utilitzar CSA perdeuterats quan es realitzen experiments de RMN per tal de determinar l'e.e de les mostres. Els propis senyals del CSA en 1H i 13C NMR desapareixen.Múltiples mètodes sintètics s'han desenvolupat per tal d'obtenir l'a,a'-diamino-9,10-antracendietà. Només utilitzant 9,10-antracendicarboxaldehid, com a reactiu de partida, i realitzant una reacció de Mitsunobu del derivat alcohol proporciona l'amina. El producte s'obté amb baix rendiment. Aquest és el motiu pel qual és rebutja l'ús d'aquesta amina com a CSA / The present work is based on the synthesis of new chiral solvating agents which are more efficient and versatile than the ones in the current market. In order to reach this objective a number of modifications have been introduced in the structure of the common CSA, such as Pirkle's alcohol, and 1-(1-naphtyl)ethylamine, and then the effect of these changes in the behaviour of these new compounds as chiral solvating agents has been evaluated. From this work several facts and conclusions can be stated. The alcohol, 2,2-dimethyl-1-(1-naphthyl)propanol, has been synthesized and its enantiomers have been separated but its capacity as chiral solvating agent seem to be not as good as the capacity of Pirkle's alcohol.The compound a,a'-bis(trifluoromethyl)-9,10-anthracenedimethanol has been synthesized and their diastereoisomers have been separated efficiently. The good behaviour of this product as a chiral solvating agent (CSA) towards several enantiomeric molecules has been tested. This alcohol has showed a large capacity to induce enantiodifferentiation in racemic mixtures, which shows, in all cases, a much better capacity than using Pirkle's alcohol. The stoichiometry of the association complexes has been determined concluding that the ratio is usually 1:1, although this alcohol presents two functional groups. A study of the equilibrium constant (K) has been carried out and has been demonstrated that K increases when temperature decreases.Furthermore, it has been developed a synthesis to obtain enantiopure (R,R)-a,a'-bis(trifluoromethyl)-9,10-anthracenedimethanol in a very good yield.This alcohol has also been tested as a chiral auxiliary in a Diels-Alder reaction. The mono-acrylate of this alcohol has been obtained and it has reacted with cyclopentadiene to form distereoisomeric adducts. The d.e obtained is 70%. It is the same as the one obtained when Pirkle's acrylate is used.A synthetic method has been developed to obtain perdeuterio--a,a'-bis(trifluoromethyl)-9,10-anthracenedimethanol and the advantages of using a perdeuterated CSA are clearly showed when NMR experiments are made to determine e.e of the samples. The own signals of the CSA in 1H and 13C NMR disappear.Several synthetic methods have been developed to obtain a,a'-diamino-9,10-anthracenediethane. But only using 9,10-anthracendicarboxaldehide, as starting material, and making the Mitsunobu reaction of its alcohol derivative afforded the amine. The compound is obtained in low yield, so that is the reason why the use of this amine as CSA is rejected.
22

Experiencing the impact of child sexual abuse within intimate partner relationships

Thorpe , Angela Joy 14 April 2011 (has links)
The purpose of this study was to illuminate the experienced impact of childhood sexual abuse (CSA) within the context of intimate relationships. Few studies have examined the lived experience of CSA within the context of a relationship from the perspective both partners. Further, previous research in the area of CSA has primarily focused on the trauma experienced by the survivor, thus excluding the impact of CSA on the couple relationship. Examining the impact of CSA on intimate relationships is important as those individuals in close relationship with the survivor will often also experience the impact of the long-term sequelae associated with CSA. Interpretative phenomenological analysis (IPA) was used to explore the lived experiences of individuals who have experienced CSA and their partners. Data generated during two joint interviews with three participant couples were transcribed and analysed using an interpretative phenomenological analysis approach. An over-arching theme of hope and healing: past yet present, healed yet healing emerged from the data; this theme was impacted by the additional themes identified throughout the analysis process. The additional three themes were: living with the unknown, (barely) surviving, and commitment. Given the limited research on the impact of CSA on intimate partnerships and the focus of existing studies on the more negative aspects of the impact CSA has on relationships, the theme of hope and healing: past yet present, healed yet healing provides a valuable contribution to the literature. These themes are discussed along with implications for counselling practices and future research.
23

Analysis of new and alternative encryption algorithms and scrambling methods for digital-tv and implementation of a new scrambling algorithm (AES128) on FPGA. / Analys av nya alternativa krypteringsalgoritmer och skramblingsmetoder för digital-TV samt implementation av en ny skramblingsalgoritm (AES128) på FPGA.

Bengtz, Gustaf January 2014 (has links)
This report adresses why the currently used scrambling standard CSA needs a replacement. Proposed replacements to CSA are analyzed to some extent, and an alternative replacement (AES128) is analyzed. One alternative being the CSA3, and the other being the CISSA algorithm. Both of the proposed algorithms use the AES algorithm as a base. The CSA3 combines AES128 with a secret cipher, the XRC, while CISSA uses the AES cipher in a feedback mode. The different utilizations makes CSA3 hardware friendly and CISSA software friendly. The implementation of the Advanced Encryption Standard (AES) is analyzed for a 128 bit key length based design, and a specific implementation is presented.
24

Community Supported Agriculture Membership: Characterizing Food and Sustainability Behaviors

January 2011 (has links)
abstract: Community Supported Agriculture programs (CSAs) have become a viable local source of fresh agricultural goods and represent a potentially new way to improve fruit and vegetable consumption among individuals and families. Studies concerning CSAs have focused mainly on characteristics of the typical CSA member and motivations and barriers to join a CSA program. The purpose of this study was to examine whether behavior and attitudinal differences existed between current CSA members and a nonmember control group. Specifically, ecological attitudes, eating out behaviors, composting frequency, and family participation in food preparation were assessed. This study utilized an online survey comprising items from previous survey research as well as newly created items. A total of 115 CSA member and 233 control survey responses were collected. CSA members were more likely to be older, have more education, and have a higher income than the control group. The majority of CSA members surveyed were female, identified as non-Hispanic and Caucasian, earned a higher income, and reported being the primary food shopper and preparer. The majority of members also noted that the amount and variety of fruits and vegetables they ate and served their family increased as a result of joining a CSA. CSA members were more ecologically minded compared to the control group. Frequency of eating out was not significantly different between groups. However, eating out behaviors were different between income categories. CSA members spent significantly more money at each meal eaten away from home and spent significantly more money on eating out each week. In both cases, controlling for income attenuated differences between groups. CSA members composted at a significantly higher rate and took part in other eco-friendly behaviors more often than the control group. Finally, no significant difference was evident between the two groups when analyzing family involvement in food preparation and meal decision-making. Overall, some significant attitudinal and behavioral differences existed between CSA members and non-CSA members. Further research is necessary to examine other distinctions between the two groups and whether these differences occur as a result of CSA membership. / Dissertation/Thesis / M.S. Nutrition 2011
25

Comunidade que sustenta a agricultura : a reaplicação da tecnologia social a partir dos casos pioneiros em Brasília

Torres, Camila Lombardi 12 December 2017 (has links)
Dissertação (mestrado)—Universidade de Brasília, Instituto de Artes, Programa de Pós-Graduação em Design, 2017. / Submitted by Raquel Almeida (raquel.df13@gmail.com) on 2018-04-10T17:59:02Z No. of bitstreams: 1 2017_CamilaLombardiTorres.pdf: 3511823 bytes, checksum: 0f3ae82e2e7ad672bad2e57384b70703 (MD5) / Approved for entry into archive by Raquel Viana (raquelviana@bce.unb.br) on 2018-04-20T18:07:50Z (GMT) No. of bitstreams: 1 2017_CamilaLombardiTorres.pdf: 3511823 bytes, checksum: 0f3ae82e2e7ad672bad2e57384b70703 (MD5) / Made available in DSpace on 2018-04-20T18:07:50Z (GMT). No. of bitstreams: 1 2017_CamilaLombardiTorres.pdf: 3511823 bytes, checksum: 0f3ae82e2e7ad672bad2e57384b70703 (MD5) Previous issue date: 2018-04-20 / Nesta dissertação, discute-se a reaplicação da tecnologia social Comunidade que Sustenta a Agricultura (CSA) em Brasília ao se investigar características de seus três casos pioneiros — CSA Barbetta, CSA Aldeia do Altiplano e CSA Toca da Coruja. Adotam-se como métodos de pesquisa: a observação participante; a revisão teórica dos conceitos de estrutura, função, processo e forma de Milton Santos e de linguagem de padrões de Christopher Alexander; a realização de atividade em campo para coleta de dados; e a apropriação da ferramenta blueprint de serviços para a concepção de representações gráficas do modo de organização de cada comunidade. Por fim, compara-se a prática dos princípios de CSA nos três casos abordados e inferem-se padrões de gestão categorizados por formação, produção, distribuição, avaliação, integração, circulação de capital e canais de comunicação. / We discuss the reapplication of the social technology Community Supported Agriculture (CSA) in Brasilia when investigating characteristics of its three pioneer cases - CSA Barbetta, CSA Aldeia do Altiplano and CSA Toca da Coruja. The followed research methods are adopted: participant observation; theoretical review of the Milton Santos' concepts of structure, function, process and form, and Christopher Alexander's pattern language; field research for data collection; and service blueprint tool for the conception of graphical representations of each community's organization method. Finally, we compare the practice of the CSA principles in the three cases mentioned and we infer management patterns categorized by conception, production, distribution, evaluation, integration, capital circulation and communication channels.
26

Well-being, coping and growth following trauma : a thesis research portfolio

Turnbull, Fiona Claire January 2015 (has links)
This thesis portfolio consists of two key pieces of work, a systematic review and an empirical research project, both of which explore outcomes associated with traumatic experiences. Systematic Review – There is a growing body of literature which demonstrates that, alongside the difficulties people may experience following trauma, many individuals are also likely to report growth following the struggle to come to terms with the event. This review explores the evidence for a relationship between reported growth and distress following civilian, interpersonal trauma. The review includes 13 studies which met the inclusion criteria (9 cross-sectional and 4 prospective). Findings are inconsistent and suggest that prospective study designs are more likely than cross-sectional designs to report significant relationships. A number of methodological issues and the implications for future research are discussed. Empirical Research Project – Survivors of childhood sexual abuse (CSA) present with a wide range of difficulties and the current evidence base for the treatment of complex trauma is limited. It is proposed that self-compassion and forgiveness based approaches may have the potential to be of benefit to this population. This cross-sectional study explored the relationships between posttraumatic stress symptoms, dissociation, self-blame, self-compassion and forgiveness. A clinical sample of adult survivors of CSA (N = 19) completed all measures. In keeping with previous literature, significant relationships were found between posttraumatic stress and both dissociation and self-blame. Forgiveness was positively correlated with dissociation, but not the other variables and no significant relationships were found between self-compassion and the variables of interest. Findings, implications and study limitations are discussed.
27

The effects of impure water sources on the early-age properties of calcium sulfoaluminate cements

Long, Wendy 13 December 2019 (has links)
One of the benefits of calcium sulfoaluminate (CSA) cements is that these materials gain strength rapidly, where strength development is often measured in hours instead of days. This property makes these materials desirable for use in temporary, non-reinforced repairs of roadways, airfields, and navigable locks. The rapid repair of these infrastructure elements is critical to transporting supplies into regions devastated by disaster. In these austere environments, potable water may not be available in sufficient quantities to make vital repairs, and the use of impure water in the production of CSA cement-based concrete would be advantageous. However, the hydration products formed by CSA cement are substantially different from those formed by portland cement and may react differently to impurities that water sources may contain. This Thesis investigates the impact of various salts and impure water sources on the early-age strength development of commercially-available CSA cement-based concrete.
28

Syndrom CSA u dětí / Child Sexual Abuse Syndrome

Špinková, Tereza January 2011 (has links)
Thesis CSA syndrome in children, examines current issues of sexual abuse and its consequences. The theoretical section deals with the history of sexual abuse, contemporary view on this issue and the legal treatment of offenders and victims. Furthermore, thesis acquaints readers with various types of sexual abuse and marginally with commercial abuse. The aim of the research in the practical section of the thesis is to ascertain the level of awarness of students in this issues, together with their own personal experience concerning sexual abuse and whether they have any sexually abused person in their vicinity. The quantitative research was conducted at the elementary school Drtinova.
29

Justificativas em torno das Comunidades que Sustentam a Agricultura: um estudo de caso da CSA São Carlos/SP / Justifications around Community Supported Agriculture: a case study on CSA São Carlos / SP

Torunsky, Flavia 26 February 2019 (has links)
Estudos mostram que vivemos uma crise socioambiental sem precedentes. Apesar de ser considerada uma crise sistêmica, a agricultura convencional progride, constituindo uma das atividades que mais contribui para os impactos negativos tanto ambientais como sociais da atualidade. No mundo, as relações socioeconômicas estão estabelecidas segundo uma ordem de valores, na qual justificações mercantis e industriais possuem uma grande aceitação e legitimidade. A economia é considerada, para alguns autores, como o coração das ações humanas. No entanto, tal ordenamento fundado em justiça industrial-mercantil impacta negativamente diversas dimensões da vida em sociedade. Neste quadro, movimentos de contestação desta ordem emergem buscando legitimidade com vistas à profundas transformações sociais e ambientais. É assim que ocorre a multiplicação das CSAs (Comunidade que Sustenta a Agricultura), representando uma experiência inovadora de associativismo, aproximando consumidores e agricultores. Seu crescimento é exponencial no Brasil e no mundo. Trata-se de uma perspectiva de busca de uma nova estrutura de relação socioeconômica com a agricultura familiar, pautadas em princípios de um compromisso com a agroecologia, a solidariedade, a confiança mútua e a localidade. Nosso estudo aspira traçar seus potenciais e limitações em termos de aceitação social com o apoio de análises inspiradas na teoria das justificações, considerando a emergência de uma nova ordem de justiça, a justiça ecológica. / Studies show that we are experiencing an unprecedented socio-environmental crisis. Despite considered a systemic crisis, conventional agriculture is progressing, constituting one of the activities that contributes most to the negative environmental and social impacts in present time. In the world, socioeconomic relations are established according to an order of values, in which market and industrial justifications have great acceptance and legitimacy. The economy is considered, for some authors, as the heart of human actions. However, such an order based on industrial-mercantile justice impacts negatively various dimensions of life in society. In this context, movements contesting this order emerge seeking legitimacy towards profound social and environmental transformations. This is how CSAs (Community Supported Agriculture) multiply, representing an innovative experience of associativism, bringing together consumers and farmers. Its growth is exponential in Brazil and in the world. It seeks a new socioeconomic relationship structure, based on a commitment to an agroecological agriculture, solidarity, mutual trust and locality. Our study aspires to trace its potentials and limitations in terms of social acceptance with the support of analyzes inspired by the theory of justifications, considering the emergence of a new order of justice, the ecological justice.
30

Varumärken som tar ställning : En kvalitativ studie om svenska konsumenters attityder till varumärkens engagemang i kontroversiella frågor

Hassinen, Gabriel, Lindroth, Anton January 2021 (has links)
Denna studie har baserats på fenomenet Corporate Social Advocacy (CSA) som innebär att företag gör ställningstaganden i socialpolitiskt kontroversiella frågor. Utmärkande för denna typ av frågor är att det inte brukar råda någon konsensus och det existerar två sidor med helt skilda åsikter. Syftet med denna studie var att öka förståelsen för svenska konsumenters attityder till CSA och varumärken som engagerar sig i det. För att utföra studien har en teoretisk referensram utvecklats som inkluderar bland annat attityder där det ingår teorier som balansteori och Theory of planned behavior (TPB). Den teoretiska referensramen inkluderade även teorier om varumärken, där till exempel varumärkesbild ingår.  Studien använde sig av en kvalitativ metod, där tolv intervjuer har utförts för att samla in empiri om svenska konsumenters attityder till varumärken som engagerar sig i CSA. Intervjuerna utfördes genom att respondenterna fick ta del av fyra exempel där varumärken har engagerat sig i en socialpolitiskt kontroversiell fråga. Till varje enskilt exempel fick respondenterna frågor rörande deras attityder gentemot varumärkena. Efter intervjuerna analyserades den insamlade datan med hjälp av den teoretiska referensramen. Studien kom fram till att respondenterna generellt var skeptiska till hur genuina företagen är i sina ställningstaganden. Studien visade också att respondenternas varumärkesbild förändrades beroende på respondenternas personliga attityd till ställningstagandet. Respondenterna uttryckte att ställningstagandena sällan gör varumärkena unika eller att det var något som de skulle associera med varumärket i framtiden. Till sist visade studien att respondenterna uppfattade att varumärkets produkt hade en starkare effekt på köpavsikten än attityden till varumärkets ställningstagande. / This study was based on the phenomenon Corporate Social Advocacy (CSA) which means that a company takes a position in a sociopolitical issue. CSA is often characterized by a lack of consensus and different sides with completely different opinions. The purpose of the study was to increase the understanding of Swedish consumers' attitudes towards CSA and the brands engaging in that. To perform the study, a theoretical framework was created which included theories about attitudes such as Balance Theory and Theory of planned behavior (TPB). The theoretical framework also included theories about brands such as brand image and was used to support the data collection and analysis.  The study used a qualitative method, where twelve interviews were conducted to collect data about Swedish consumers' attitudes towards brands that engage in CSA. The interviews were performed by exposing the participants to four examples of brands engaging in sociopolitical issues. The participants were then asked questions about each example. After the interviews, the data was analysed with the help of the theoretical framework. The study concluded that respondents were skeptical whether or not companies genuinely cared for their sociopolitical issues. The study also showed that respondents' brand image changed based on respondents' personal attitude towards the sociopolitical issue. Respondents also expressed that CSA did not make the brand unique or was something they would associate with the brand in the future. Lastly the study showed that respondents perceived that the brand's product had a stronger influence on the purchase intention than the attitude towards the brands position in a sociopolitical issue.

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