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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.
111

Synthesis of Poly(p-phenylene vinylene) within Faujasite and Linde Type A Zeolites: Encapsulation for Improved Optical Properties

Heck, Elizabeth Maria 22 July 2011 (has links)
No description available.
112

An Investigation into the Effects of Gating in Artificial Host Systems

Rieth, Stephen E. 08 September 2011 (has links)
No description available.
113

Host Communities and the Refugee Crisis A Case Study of Kos Island, Greece

Rozali, Eleni Maria January 2016 (has links)
During an extraordinary political current event, how does a host community’s reputation change, and how does the media attempt to influence public opinion towards, or away from, such a destination? What is the host community’s perception of and response to these representations? This topical study explores the effects of the media on a refugee host community, through the conceptualization of the host and the discourse of hospitality. Significant to this study is the framing of tourism as a cultural exchange and expression, how hosts and guests view the realm of “place” and boundaries, and the volatility of the tourism industry with regards to communication mediums, socioeconomic and current events. This study acknowledges the gravity of the current refugee crisis, and the refugee and migrant experiences on Kos Island from May 2015 to present, while exploring and attempting to understand a host community’s reality while balancing political and ethical considerations in terms of hospitality towards guests, whether “invited” or “uninvited”, and the related media representations. By applying concepts of hospitality, i.e. accommodating strangers, and the social constructs of hospitality, imagined communities and how these are shaped by the media, I seek to acquire a broader understanding of development communication in terms of the human rights that both communities are entitled to, as opposed to the reality afforded to them. Using media content analysis and qualitative methods, this exploratory study focuses on the case of Kos Island, Greece - one of the main entry points for refugees from Syria, Afghanistan and Iraq - due to the island’s proximity to Turkey. By presenting a media content analysis, I frame how the host community was portrayed in the media to shape public opinion, by pinpointing the frequency and prism under which Kos Island was mentioned in the UK press during the height of the refugee crisis in 2015. I also conduct semi-structured interviews with local and international tourism industry gatekeepers, to uncover effects of the crisis on Kos Island’s tourism industry. This qualitative data is reinforced with a personal ethnographic account from the summer of 2015. I anticipate that the topics surfacing from this discussion allow readers to gain a broader perspective into development communication, through the power relations between hosts and guests/tourists (including refugees and migrants), the importance of public spaces and how they are used by host community and guests (tourists and refugees), and the ethics of hospitality.
114

The effect of chirality and steric hindrance on intrinsic backbone conformational propensities: tools for protein design

Childers, M.C., Towse, Clare-Louise, Daggett, V. 11 May 2016 (has links)
No / The conformational propensities of amino acids are an amalgamation of sequence effects, environmental effects and underlying intrinsic behavior. Many have attempted to investigate neighboring residue effects to aid in our understanding of protein folding and improve structure prediction efforts, especially with respect to difficult to characterize states, such as disordered or unfolded states. Host-guest peptide series are a useful tool in examining the propensities of the amino acids free from the surrounding protein structure. Here, we compare the distributions of the backbone dihedral angles (φ/ψ) of the 20 proteogenic amino acids in two different sequence contexts using the AAXAA and GGXGG host-guest pentapeptide series. We further examine their intrinsic behaviors across three environmental contexts: water at 298 K, water at 498 K, and 8 M urea at 298 K. The GGXGG systems provide the intrinsic amino acid propensities devoid of any conformational context. The alanine residues in the AAXAA series enforce backbone chirality, thereby providing a model of the intrinsic behavior of amino acids in a protein chain. Our results show modest differences in φ/ψ distributions due to the steric constraints of the Ala side chains, the magnitudes of which are dependent on the denaturing conditions. One of the strongest factors modulating φ/ψ distributions was the protonation of titratable side chains, and the largest differences observed were in the amino acid propensities for the rarely sampled αL region. / NIH
115

Efficient Syntheses of Strong Binding Cryptands and their Derivatives for Supramolecular Polymer Synthesis

Pederson, Adam Micheal-Paul 07 March 2009 (has links)
Production of efficiently synthesizable, strongly associating crown ether-based cryptands is desired for pseudorotaxane complexation of bipyridinium guests to produce suprapolymers and supramolecularly-linked block copolymers. Cryptands based on bis(meta-phenylene)-32-crown-10 (BMP32C10) were synthesized. The functionality of phenylenemethanol-BMP32C10 cryptand III-3 (Ka = 2.0 x 104 M-1) did not negatively affect binding strength, although the strength of complexation is marginal to achieve the desired suprapolymers. The cryptand dimethylpyridyl-BMP32C10 IV-2 was synthesized in an attempt to improve over the binding ability of the pyridyl-BMP32C10 cryptand IV-1; instead, interesting host design insights were discovered as binding strengths were reduced over 1000-fold. The crystal structure of IV-2 shows acyl-aryl conjugation which limits the host's ability to accept guests. Synthesis of larger cis-di(carbomethoxybenzo)-3n-crown-n crown ethers was explored using the high concentration, template technique previously reported for cDB24C8 diester. cDB30C10 diester (V-1c) was produced in 93% yield; the desired pyridyl-cDB30C10 cryptand V-12 binds paraquat strongly (Ka = 1-2x105 M-1) and diquat stronger than any other host (Ka = 1.9x106 M-1), both in 1:1 fashions; association constants were measured by ITC. X-ray crystallography of the complexes shows the cryptand's para arm is too far away to interact with paraquat and the host has numerous bifurcated interactions with diquat, explaining the difference in binding strengths. Syntheses of the regioisomers of cDB27C9 diester was also explored; the cyclization yields (cDB27C9S, VI-2: 59% and cDB27C9L, VI-3: 44%) are lower, likely due to poor attack angles due to mismatched arm length in cyclization, than the equivalent length ethyleneoxy-armed cDB24C8 and cDB30C10. Modeling of the cryptand isomers, pyridyl-cDB27C9S and pyridyl-cDB27C9L, showed that the former should improve para arm interaction with paraquat, but should be sterically hindered for diquat and the latter should have a highly flexible, poorly preorganized interaction with either type of guest. ITC, MS, and crystallography data supported the predictions. Derivatization of the pyridyl-cDB30C10 cryptand V-12 was explored using chelidamic acid (VII-1). Schemes yielding alcohol, alkyl halide, alkyne, and TEMPO functionality were followed, but failed. Currently, functionalized cryptand derivatives have not been achieved, future directions are proposed. / Ph. D.
116

The Chemistry of Fullerenes, Polymers, and Host/Guest Interactions

Schoonover, Daniel Vernon 03 March 2015 (has links)
The exploitation of the relationship between the chemical and physical properties of materials is the hallmark of advancing science throughout the world. The basic understanding of how and why molecules react and interact with each other in different environments allows for the discovery and implementation of new materials and devices that not only advance the state of human life but continually change the planet. The work described in this dissertation generally falls under three diverse categories: functionalization of fullerenes, investigation of host/guest interactions in solution, and the synthesis and characterization of ion containing polymers. The separation and functionalization of fullerenes is a recent and exciting area of research. The separation methods outlined are intended to increase the availability of endohedral metallofullerenes by decreasing their cost of production. Functionalized fullerene species were achieved through Bingel and Prato reactions to provide materials with novel functional groups. These materials may be further utilized in photovoltaic or other organic electronic devices. The characterization of noncovalent interactions between different molecules in solution is the focus of supramolecular chemistry. Isothermal Titration Calorimetry stands out as one of the best, among the many methods used to elucidate the characteristics of these systems. The binding of bis- imidazolium and paraquat guests with macrocyclic host molecules has been explored in this work. The measurements of the association constants for these systems will aid in the ongoing synthesis of new host/guest systems. Ion containing polymers were synthesized and characterized for their use in electroactive devices. Imidazolium containing polymers with bulky anions were synthesized on low glass transition polymer chains. These materials had enhanced ion conductivity and may eventually be used in electronic actuator materials. / Ph. D.
117

Immersive Exploration Experiences: Using Multi-Branching Decision Narratives as a Design Framework for Advanced Audience Engagement

White, Arianna 01 January 2023 (has links) (PDF)
Although ‘immersive experiences' and ‘immersion' are popular keywords in the themed entertainment industry today, they lack clear definition and criteria in their design and application. Nevertheless, there has been an increase in guest demand for these types of experiences and for these spaces to develop innovative methods that increase the degree to which audiences are able to engage with them. This thesis iterates cohesive design criteria for immersive experiences as they continue their trend toward increased engagement, interactivity, and guest agency in physical manifestations of imaginary worlds. This trend is explored through contextual references from the industry and an assessment of their implementation of the criteria towards increasingly immersive spaces. However, the current trajectory of these experiences does not demonstrate holistic consideration of the various elements required to progress towards true “advanced immersion” for the future of themed design. A new design practice is put forward for practitioners: “Immersive Exploration Experiences.” This framework progresses towards advanced immersion by considering varied guest roles and offering personalized, branching narrative structures as a key tenet. The Immersive Exploration Experiences concept is further illustrated with example design implementations accompanied by exploration tree diagrams that show the combination of dynamic, interactive, and engaging elements. The intent of this thesis is to provide a template for creating next generation immersive experiences which are built upon dynamic guest roles, transformative spaces, repeatable narratives, and other advanced elements that give every guest an opportunity to create their own path through an imaginary world.
118

Ubytovací penzion v obci Mšené – lázně / Accommodation guest house in Mšené-lázně

Dudková, Jana January 2015 (has links)
The project deals a accommodation guest house with restaurant in Mšené-lázně. The object has a partial basement and it has three aboveground floors. Restaurant, kitchen´s operation and background of the guest house are located in first aboveground floor. A total of twenty-two guest rooms are located in second and third aboveground floor. The building is covered with gabled, half-hipped roof and flat roof.
119

Syntéza cyklodextrinových derivátů pro praktické aplikace / Synthesis of cyclodextrin derivatives for practical applications

Popr, Martin January 2017 (has links)
Synthesis of cyclodextrin derivatives for practical applications Abstract The first part of this PhD thesis is focused on the synthesis of a series of monosubstituted tetraalkylammonium cyclodextrin (CD) derivatives. The emphasis was placed on the possible applicability of the synthetic process to multigram or even industrial scale. Monotosylation of the native cyclodextrins (-, -, -) on the primary side of the macrocycle afforded the starting materials. Derivatives with one cationic group were prepared by the reaction with aqueous trimethylamine. The reaction of the mono-Ts-CD with neat N,N,N'-trimethylethane-1,2-diamine or N,N,N'-trimethylpropane-1,3-diamine and subsequent methylation led to derivatives with the substituent bearing two cationic groups (PEMEDA- and PEMPDA-β-CD). Analogs bearing a moiety with three tetraalkylammonium sites were synthesized by reaction of mono-Ts-CD with bis(3-aminopropyl)amine with subsequent methylation. 1,3-Dipolar cycloaddition of mono-6- azido--CD with diaminoacetylenes followed by methylation led to analogs with a avariable distance of the charged substituent from the CD core. Majority of the presented reactions are straightforward, relatively high-yielding and the workup does not require chromatographic steps. The second part of the work is dealing with the...
120

Ion-pair and anion recognition by macrocycles and interpenetrative assemblies

Picot, Simon C. January 2013 (has links)
This thesis investigates the design and synthesis of macrocycles and examines their ion-pair recognition, anion recognition and interpenetrative assembly capabilities. Chapter One introduces the field of supramolecular chemistry. Key concepts in host–guest complexation and self-assembly are outlined, with particular emphasis on the design of host systems for anion and ion-pair recognition. Chapter Two details the synthesis and binding properties of a heteroditopic 1,2,3-triazole- containing macrocycle that exhibits cooperative ion-pair recognition. Solution and solid-state evidence shows that the triazole motif simultaneously binds anions and cations. The exten- sion of this work towards the formation of interlocked structures containing an expanded heteroditopic macrocycle and threading components is explored. Chapter Three discusses the design and syntheses of series of electron-deficient macrocycles based on imidazolium, pyridinium and triazole. These are investigated for anion binding ability and assembly of interpenetrative assemblies with electron-rich threading components. Chapter Four describes research into the formation of interpenetrative assemblies using neutral components. Their design is based around aromatic donor–acceptor interactions and halogen bonding. Chapter Five presents some conclusions from the research undertaken. Chapter Six provides titration protocols, Job plot approximations, experimental procedures and characterisation of the compounds described in this thesis. Appendix details additional X-ray crystallographic data.

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