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Dissertations / Theses on the topic 'Tetramino'
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1
Patience, J. M. "Routes to substituted tetramic acids." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235998.
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Schollin, Mårten. "Formulation and Assessment of Hexamethylene-tetramine Filled Solid Fuel Grains." Thesis, KTH, Fiber- och polymerteknologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297507.
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Hybridraketer har inte sett så mycket användning som dess motsvarigheter som använder flytande eller fasta drivmedel. De främsta orsakerna kan förklaras med att hybridraketer historiskt sett haft lägre regressionshastighet och bränsletäthet. Inverkan av nackdelarna har dock minskat tack vare fortsatt forskning rörande hybridraketer. Tillsammans med de säkerhetsoch ekonomiska fördelar som kommer med hybridraketer har gjort hybridraketer ett mer konkurrenskraftiga. Hexaminbaserade fasta bränslen har formulerats och utvärderats med betoning att förbättra härdningstid och mekaniska egenskaper. Genom att inkludera mjukgörare och ändra NCO/OH-förhållandet har ett fast bränsle med lovande mekaniska egenskaperoch god härdningstid framställts.<br>Hybrid propellant rockets has not seen as much use as its liquid and solid propellant counterparts. The main reasons for this can be attributed to hybrid propellant rockets historically having lower regression rate and fuel density. However, the impact of these disadvantages have been diminished over the years as a result of increased research. This together with the safety and economic advantages of hybrid propellant rockets, the hybrid system have become a more competitive system to use. Hexamine basedsolid fuel grains have been formulated and evaluated with emphasis on enhancing pot-life and tensile proprieties. By including plasticisers and altering the NCO/OH ratio, a solid fuel grain was successfully produced, overcoming earlier encountered problems with short pot-life as well as having promising tensile properties.
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Bates, Andrew D. "New reactions in tetramic acid synthesis." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252629.
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Pillainayagam, Terence Anthony. "New methods in tetramic acid synthesis." Thesis, Loughborough University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416685.
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Law, Ching-Man (Carole). "Novel tetramic acids via 1,3-dipolar cycloaddition." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/34454.
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This Ph.D. thesis has been concerned with the reinvestigation and improvement of the intermolecular 1,3-dipolar cycloaddition strategy using isoxazoles, towards the 3-acyltetramic acids (3-acylpyrrrolidine-2,4-diones) and also the investigation and development of the corresponding intramolecular strategy. A second generation of the intermolecular route was developed previously within our group and we have synthesised a variety of pyrroloisoxazoles, the 'masked' tetramic acids. We have modified and improved both the isoxazole formations and the peptide coupling reactions; we have further developed the chain extension at the isoxazole C-5 (tetramic acid C-3) substituent, testing the aldol-type reaction with some aromatic aldehydes and extending it to aliphatic aldehydes. We have demonstrated the condensation method using a strong base and hydroxyl adducts were obtained. Dehydration has been undertaken to yield the alkenyl C-5 side-chain. Development of the desmethyllaccarin, a derivative of the natural product laccarin, has also been attempted via the intermolecular route. A potential intramolecular route has the reversed sequence from the intermolecular route, by using the N-acylation product produced from an amino acid for the formation of a nitrile oxide and hence our building block pyrroloisoxazole by intramolecular dipolar cycloaddition. We have generated a nitro ketoester compound from the amino acid and investigation on the synthesis of the pyrroloisoxazole has been undertaken.
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林躍年 and Yeuk-nin Lam. "Kinetic and mechanistic studies of some cis-macrocyclic tetramine and tetrathioether complexes of ruthenium." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1985. http://hub.hku.hk/bib/B31206979.
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Lam, Yeuk-nin. "Kinetic and mechanistic studies of some cis-macrocyclic tetramine and tetrathioether complexes of ruthenium /." [Hong Kong : University of Hong Kong], 1985. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12264015.
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Lewis, Ian. "Studies in the synthesis of polyene tetramic acid antibiotics." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/12412.
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Wilson, Jason B. "Synthesis and evaluation of tetramic acids as antimicrobial agents." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-055-Wilson-Index.htm.
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Thesis (M.S.)--University of Tennessee Health Science Center, 2008.<br>Title from title page screen (viewed on February 27, 2009). Research advisor: Richard E. Lee, Ph.D. Document formatted into pages (viii, 40 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 36-40).
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Duller, Kathryn April Marion. "A cycloaddition route to heterocyclic tricarbonyl natural products." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307821.
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Zhang, Jin. "Regulation of apolipoprotein A-I gene expression in Hep G2 cells depleted of copper by cupruretic tetramine." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186914.
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Two cupruretic chelators, 2,3,2-tetramine and diamsar were used to deplete copper from Hep G2 cells. Studies using incremental concentrations of chelators, an average maximal depletion of 45% of cellular Cu amounting to 2.4 or 2.3 pmol Cu/μg DNA were attained after 24 h of incubation with 10 μM of tetramine or diamsar in basal medium containing 0.63 μM of Cu. In time-course studies, maximal depletion of Cu was rapidly reached after only 5 h of treatment with 50 μM of these chelators for cells cultured in basal medium. In long-term Cu depletion studies, cellular Cu was reduced more than 40% as compared to controls when cells were cultured in basal medium containing 20 μM tetramine for 4 passages. At the end of the second passage, the synthesis of total protein and albumin was not altered for tetramine-treated cells. After cells were treated with tetramine for 2 passages, pulse-chase studies were performed to determine apolipoprotein synthesis and secretion. Cells were pulsed for 10 min with (³H) leucine and chased for up to 2 h. Trichloroacetic acid precipitation or immunoprecipitation and SDS-PAGE were used to isolate the nascent total protein or specific apolipoproteins, respectively. A two-fold increase in apo A-I synthesis was observed at the end of 10 min pulse in tetramine-treated cells. Although the amount of nascent apo A-I degraded was not affected, that secreted into the medium was increased 56% by tetramine treatment between 30 and 120 min of the chase. A reporter construct -256 A-I.CAT was transiently transfected into cells treated with tetramine for 2 to 3 passages to determine the influence of Cu depletion on apo A-I gene transcriptional regulation. In these Cu depleted cells, a 40% increase in CAT activity indicated that the apo A-I gene promoter activity was enhanced. In addition, the ability of apo A-I regulatory protein 1 to repress the CAT activity was not affected by tetramine treatment. Furthermore, gel shift assays indicated that the increased apo A-I gene expression was probably mediated by enhanced binding of hepatocyte nuclear factor 4 and other unknown nuclear factors to site A of the apo A-I gene promoter.
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Moore, M. Caragh. "Biosynthetic studies on tenellin and aminoisobutyrate metabolism in Streptomyces sp." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4837/.
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This thesis is divided into two parts. Part 1 covers the biosynthesis of the fungal metabolite tenellin, and Part 2 the metabolism of β-aminoisobutyrate m Streptomyces sp. Tenellin is a yellow pigment of the fungus Beamaria bassiana. It is of mixed biosynthetic origin, being derived from a polyketide moiety and the amino acid L-phenylalanine. The timing of the C-methylations of the polyketide chain is discussed in Chapter 2, which describes attempts to incorporate deuterium labelled partially assembled putative intermediates into the polyketide. The biosynthesis of the pyridone ring of tenellin requkes the condensation of the polyketide moiety with a rearranged phenylpropanoid unit derived from phenylalanine. The nature of this intriguing intramolecular rearrangement is discussed in Chapters 3 and 4. A phenylalanine derived tetramic acid, proposed as an intermediate in the biosynthesis, has been synthesised, and used in biosynthetic investigations. The results of these investigations and the subsequent identification of tyrosine as a closer precursor to tenellin argue against its intermediacy. The failure of [2-(^13)C(^2)H(^15)N]-phenylalanine to become incorporated intact suggests a transamination process for phenylalanine / tyrosine prior to incorporation. Preliminary investigations suggest para-hydroxy phenyllactate may be die substrate for the rearranging enzyme and a more direct precursor to tenellin. β-Aminoisobutyrate, the end product of reductive thymine catabolism, contributes to both the propionate and butyrate pools in Streptomyces sp. The pathway of incorporation into the isobutyrate / butyrate pool has been investigated, and confirmed to be the reverse of that known to occur in L-valine metabolism. A mutant strain of Streptomyces avemitilis, unable to produce isobutyrate, was used due to low level incorporations into the branched-chain fatty acids. This work was carried out in collaboration with Dr. Hamish McArthur, Pfizer Central Research Division, Groton, USA, and Dr. Kevin Reynolds, Department of Pharmaceutical Science, University of Maryland.
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Loscher, Sebastian [Verfasser], and Rainer [Akademischer Betreuer] Schobert. "Total synthesis of naturally occurring glycosylated tetramic acids / Sebastian Loscher. Betreuer: Rainer Schobert." Bayreuth : Universität Bayreuth, 2015. http://d-nb.info/1075249473/34.
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Hing, Sherry Ann Ong 1957. "COPPER DEFICIENCY AND HYPERLIPOPROTEINEMIA INDUCED BY N,N'-BIS-(2-AMINOETHYL)-1,3-PROPANE DIAMINE (2,3,2-TETRAMINE) IN RABBITS (CHELATORS)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276804.
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Melanophy, Claire. "Keteneylidenetriphenylphosphorane as a C2O building block in the synthesis of highly functionalised tetramic and tetronic acids." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972529942.
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Fischer, Joshua. "HIV-1 Integrase Inhibitors: A Formal Total Synthesis of Lithospermic Acid And Synthetic Studies Towards Integramycin." Thesis, The University of Sydney, 2007. http://hdl.handle.net/2123/2397.
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This thesis describes synthetic studies towards the HIV-1 integrase inhibitory natural products lithospermic acid and integramycin, resulting in a formal total synthesis of the former. A modular, flexible and convergent synthetic strategy to lithospermic acid was devised. In this approach, a Sonogashira coupling was used to unite the C1–C7 and C20–C27 fragments that were subsequently manipulated to then participate in the key step of the synthesis, a palladium-mediated carbonylative annulation. Reduction of the benzofuran nucleus with magnesium in methanol then provided the desired dihydrobenzofuran core of lithospermic acid. Various protecting group strategies were investigated to complete this sequence in an efficient manner. Further synthetic manipulations afforded the complete C1–C9/C19–C27 fragment, which was united with the C10–C18 fragment to deliver the entire carbon skeleton of lithospermic acid. A two step deprotection sequence was undertaken, however, complications with the final deprotective step prevented definitive proof that the total synthesis of lithospermic acid had been achieved. An alternate protecting group strategy was sought, and a formal total synthesis of lithospermic acid was achieved by intercepting an advanced intermediate from a previous total synthesis. Several strategies for the enantioselective synthesis of the dihydrobenzofuran core of lithospermic acid were evaluated, however, none proved successful. A synthetic route towards the tetramic acid subunit of integramycin was also investigated. 3- Methoxymaleimide was constructed using known chemistry, and the regioselective reduction of this ring system was developed. Attempts to further functionalise this ring system were thwarted by difficulties associated with handling. The scope of the regioselective reduction was investigated on an array of N- substituted methoxymaleimides with the procedure found to be generally high yielding and highly regioselective.
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Fischer, Joshua. "HIV-1 Integrase Inhibitors: A Formal Total Synthesis of Lithospermic Acid And Synthetic Studies Towards Integramycin." University of Sydney, 2007. http://hdl.handle.net/2123/2397.
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Doctor of Philosophy (PhD)<br>This thesis describes synthetic studies towards the HIV-1 integrase inhibitory natural products lithospermic acid and integramycin, resulting in a formal total synthesis of the former. A modular, flexible and convergent synthetic strategy to lithospermic acid was devised. In this approach, a Sonogashira coupling was used to unite the C1–C7 and C20–C27 fragments that were subsequently manipulated to then participate in the key step of the synthesis, a palladium-mediated carbonylative annulation. Reduction of the benzofuran nucleus with magnesium in methanol then provided the desired dihydrobenzofuran core of lithospermic acid. Various protecting group strategies were investigated to complete this sequence in an efficient manner. Further synthetic manipulations afforded the complete C1–C9/C19–C27 fragment, which was united with the C10–C18 fragment to deliver the entire carbon skeleton of lithospermic acid. A two step deprotection sequence was undertaken, however, complications with the final deprotective step prevented definitive proof that the total synthesis of lithospermic acid had been achieved. An alternate protecting group strategy was sought, and a formal total synthesis of lithospermic acid was achieved by intercepting an advanced intermediate from a previous total synthesis. Several strategies for the enantioselective synthesis of the dihydrobenzofuran core of lithospermic acid were evaluated, however, none proved successful. A synthetic route towards the tetramic acid subunit of integramycin was also investigated. 3- Methoxymaleimide was constructed using known chemistry, and the regioselective reduction of this ring system was developed. Attempts to further functionalise this ring system were thwarted by difficulties associated with handling. The scope of the regioselective reduction was investigated on an array of N- substituted methoxymaleimides with the procedure found to be generally high yielding and highly regioselective.
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Sagiraju, Sarada. "Synthesis and Spectroscopic Study of Anticancer agent A-007 Prodrugs and Progress Towards the Synthesis of Tetramic acid Antibiotics." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/900.
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4, 4'-Dihydroxybenzophenone-2, 4-dinitrophenylhydrazone (A-007) has recently completed a phase-I clinical trial, and objective responses were seen in advanced breast cancer, lung cancer, ovarian cancer, melanoma, skin cancer and non-Hodgkin's lymphoma. Despite the promising results in the clinical trials, the major disadvantage to using A-007 as a broad-scale therapeutic is its poor water solubility. To make use of this promising anticancer drug either orally or intravenously, the short-term obstacle must be to overcome the limited solubility of A-007 in water. There are several approaches to overcome this obstacle. The first approach is to make hydrolysable prodrugs of A-007. The second approach is to make an A-007 complex with a water soluble host, such as cyclodextrin. We used a combination of these two previously described methods, i.e. transforming A-007 into a more water soluble prodrugs and then further increasing the prodrug water solubility by making their cyclodextrin inclusion complexes. Our syntheses and spectroscopic explorations of A-007 prodrugs are presented in this dissertation. Tetramic acid (2, 4 pyrrolidine-2, 4-dione ring system) containing compounds have been found to display a remarkable diversity of biological activities and have attracted the interest of medicinal and synthetic chemists. Magnesidin (1-acetyl-3-octanoyl-5-ethylidene tetramic acid) has strong antimicrobial activity against bacteria that cause gingivitis and dental plaque. Current efforts toward the synthesis of Magnesidin are discussed along with the plans for the completion of synthesis.
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Pingali, Subramanya. "Towards the Synthesis of Magnesidin." ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/447.
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Magnesidin is a magnesium chelate of the 3-hexanoyl and 3-octanoyl tetramic acid derivatives isolated from Psuedomonas magensiorubra. Its activity against grampositive bacteria was found to be a specific target for Gingivitis, a dental plaque.Although the synthesis of magnesidin has been reported earlier, it was not reproducible. The highly polar nature and it’s ability to exhibit tautomerization makes their chemical behavior complex and difficult to predict its structure. A variety of reactions and an in depth understanding of the chemical structure is necessary to attain the synthesis of these compounds. This dissertation focuses on addressing the attempts towards the synthesis of Magnesidin by identifying the important intermediates necessary for the synthesis as β- keto esters, α,β-unsaturated amino esters. The focus of the work has been addressed by developing a TAG molecule approach, which is similar to the concept of solid phase synthesis except for the fact that the TAG molecule can be identified under UV and also can be detected using various spectroscopic techniques. Microwave synthesis has been explored and applied in to the synthesis of benzyl mono and di bromination, 1,3- benzodioxoles have been established. The benzyl mono bromination is applied to synthesize the TAG molecule, which is then applied in developing a method of synthesis for β-keto esters. The azide approach was used to synthesize the α,β- unsaturated amides, which are another essential class of compounds in the synthesis of magnesidin.
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Panduwawala, Tharindi. "Natural product guided antibacterial drug discovery : tetramates as core scaffolds." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:b507ca4d-ef35-4928-90a2-0a3f774a4ed2.
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This thesis describes the synthesis and biological evaluation of a library of compounds containing the tetramic acid core in search of novel antibacterial drug candidates. Chapter 1 discusses the need for new antibiotics due to the emergence of virulent bacterial strains resistant to clinically available drugs and the hiatus in the discovery of new replacement antibitoics that has become a global threat to human health. Different platforms for antibacterial drug discovery and the re-emergence of natural products-based approach that has gained importance in the quest for novel antibiotics are discussed. In this regard, the intrinsic antibacterial activity of natural products containing a tetramate core structure and the strategies developed to synthesise the core scaffold are described. Chapter 2 discusses the use of Ê-serine and Ê-cysteine in tetramic acid synthesis and the application of Ê-cysteine-derived thiazolidine templates suitable for stereoselective ring closing reactions to obtain the tetramic acid core with scope for further functionalization. Chapters 3 and 4 describe a range of synthetic routes for appropriate substitutions of the tetramate core for compound library generation. Elaboration of the tetramate core via carboxamide tetramate synthesis, Suzuki-Miyaura cross-coupling reactions, glycosylations and their aglycone analogue synthesis, etherification, tetramate-pyroglutamate systems, Buchwald aminations/amidations, cycloadditions and β-lactam hybrids as possible chemical modifications of the tetramate core structure are discussed. Chapter 5 describes the antibacetiral activity and physicochemical properties of the library of compounds synthesised. A preliminary evaluation of their antibiotic activity was conducted against S. aureus and E. coli using the hole-plate method. MICs of the tetramates synthesised were determined against several Gram-negative strains; Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Gram-positive strains; MRSA, Enterococcus faecalis and Streptococcus pneumoniae, in whole-cell bioassays. Physicochemical properties of the compound library were analysed to map the chemical space occupied by tetramates with potent antibacterial activity. Enzyme inhibition studies were conducted to identify possible modes of action that contribute to whole-cell antibiotic activity and in this regard, the inhibition of enzymes S. aureus topoisomerase IV, S. aureus RNA polymerase, E. coli RNA polymerase, E. coli gyrase and M. tuberculosis gyrase are discussed. Since plasma protein binding of compounds is an important factor that determines the bioavailability of antibiotics and their clinical outcome, a study of the binding affinity of these drug candidates to Human Serum Albumin (HSA) by both whole-cell bioassay and NMR spectroscopy-based protein binding experiments are discussed. Finally, a brief note on the potential of tetramic acids to function as proteasome inhibitors in anticancer chemotherapy is included at the end of this chapter.
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Healy, Alan R. "Development of novel modulators of protein-protein interactions associated with cancer." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6316.
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An understanding of the underlying mechanisms by which proteins engage and communicate within the complex cellular environment is critical to the elucidation of the molecular basis of disease states and the development of safer, more efficacious drug therapies. Diverse cellular functions, including replication, transcription, cell growth and intracellular signal transduction, are governed by extensive networks of protein-protein interactions (PPIs). Disruption of the finely-tuned cellular networks due to the formation of aberrant or unregulated PPIs is implicated in the development and progression of cancer. As a result, over the last decade, PPI modulation has developed as an attractive molecular target for novel cancer therapies and as a powerful research tool in chemical biology to provide insight into the cellular transformations involved in carcinogenesis. Chapter 1 provides a review of the physiological importance of PPIs and the role they play in the development and progression of cancer. A summary of the challenges associated with targeting PPIs is given, highlighting the changing perception regarding the drugabbility of PPIs and the technological and conceptual advances driving this transformation. A brief overview of the approaches used to identify PPI modulators links the reader to the appropriate chapter for further discussion and utilisation of a selection of these methods. Chapter 2 describes the application of a virtual screening approach to discover PPI modulators. In particular, the development of an in silico – in vitro screening method to identify modulators of the protein interactome of the AAA+ protein reptin. The synthesis and optimisation of two hit compounds is outlined, with a discussion of their predicted binding modes, mode of action, potential as chemical tools and lead molecules for an anti-cancer drug discovery programme. Chapter 3 highlights the potential to discover PPI modulators from Nature's rich source of structurally complex, bioactive molecules. A synthetic approach to a sub-family of tetramic acid natural products is outlined, involving the development of a short, asymmetric synthesis of unnatural 4,4-disubstituted glutamic acid derivatives. The first total syntheses of the potent siderophore harzianic acid and the PAC3 PPI inhibitor JBIR-22 are reported. In addition, the potential role of a Diels-Alderase enzyme in the biosynthesis of JBIR-22 and the development of a chiral catalysed intramolecular Diels-Alder of an advanced JBIR-22 intermediate is investigated. Chapter 4 discusses the use of structure based design techniques in the development of PPI modulators. The process involved in the design of two series of inhibitors of PICK PDZ domain mediated interactions is outlined. This leads to the development and optimisation of synthetic routes to both series of inhibitors, including the utilisation of a strategic sp3-sp2 cross coupling reaction. Finally, preliminary biological assessment of the inhibitors is reported. Chapter 5 gives a brief overview of high-throughput screening (HTS) methods used to identify PPI modulators. The utilisation of a forward chemical genetics screen to identify the p53 activator MJ05 is described. A racemic and asymmetric route to MJ05 is developed and biochemical analysis of the two enantiomers of MJ05 is reported including the investigation of MJ05 as an adjuvant therapy for the treatment of cancer. Chapter 6 provides a general overview of the outcome of the different approaches used in this research to discover PPI modulators. Particular emphasis is placed on the development of chemical tools for the elucidation and dissection of the physiological role of protein-protein interactions and the identification of novel drug targets, in addition to the identification of lead molecules for PPI drug development programmes.
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Pöhlmann, Milena. "Thermisch härtende Polymerverbundmaterialien als Basis für neue Befestigungssysteme." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1165492370619-99312.
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Mit der Entwicklung und Einführung ökologischer Bauweise im Neubau sowie neuen Baustoffsystemen in Sandwichbauweise wird es zunehmend erforderlich, neue effektive Befestigungsvarianten zu entwickeln, die eine dauerhafte Fixierung auch unter sicherheitstechnischen Bestimmungen sowie aus Garantie- bzw. haftungsrechtlichen Gründen ermöglichen. Die aus der Praxis bisher bekannten chemischen Befestigungssysteme (Zweikomponentenverbundmörtel, Verbundankerpatronen) weisen hinsichtlich der Applikation unter bautechnischen Bedingungen noch einige Nachteile auf. Dazu gehören vor allem längere Aushärtungszeiten zur Realisierung der abschließenden Verbundfestigkeit, Inhomogenitäten im Verbund, der Einsatz toxischer Verbindungen und eine Limitierung der Applikationsmöglichkeiten in horizontalen und Überkopf-Einsatzbereichen sowie Hohlkammersystemen. Alle zuvor genannten Punkte haben bis jetzt die Nutzung solcher Verbundwerkstoffe als universale Anwendungsmöglichkeit verhindert. Ein neues chemisches Befestigungssystem, welches aus Novolak gehärteten mit Hexamethylentetramin (Hexa) und anorganischen Füllstoff besteht, wurde für Applikationen in Beton entwickelt. Das Bindemittel härtet bei der Temperaturzuführung aus. Die unkatalysierte Befestigungsmasse zeigt bei einer Temperatur zwischen 150-300 °C eine hohe Reaktivität. Die Vorteile dieses Systems sind die unbegrenzte Lagerfähigkeit der vorgemischten härtbaren Masse sowie die Gewährleistung einer homogenen Netzwerkstruktur im gesamten Verbund und sie ist frei von giftigen und flüchtigen Substanzen. Auf den Einsatz toxischer Substanzen wurde verzichtet. In dieser Arbeit wurde die Gesamtkinetik der Reaktion während des Aushärtungsprozesses dieser Polymerkomposite untersucht. Die DSC- (nicht-isothermen, isothermen) und MDSC-Untersuchungen haben sich als ein sicheres Verfahren zur Qualitätskontrolle des Aushärtezustands der Befestigungssysteme herausgestellt. Parallel zur nicht-isothermischen und isothermischen DSC wurden Leitfähigkeitsmessungen durchgeführt, um den Endpunkt der Aushärtungsreaktion zu bestimmen<br>The development and introduction of ecological construction methods and the use of sandwich materials make it necessary to develop new fixing systems and technologies. Dealing with the application in concrete and other substrates commercial chemical fixing systems show some disadvantages up to date. Especially the rather long curing time in order to realize the final bond strength, inhomogenities in the composite, the partial use of toxic substances and application limits of such systems in horizontal direction as well as hollow section materials has so far prevented the use of such composites for all-purpose applications. A new chemical fixing system, which consists of hexamethylene tetramine (hexa) cured novolac and inorganic filler, was developed for application in concrete. It is applied by a thermo-curing procedure. The uncatalyzed curable mixture has a high reactivity at temperature between 150-300 °C. Compared with commercial chemical fixing systems, the premixed curable mass has many benefits. First it has a unique storage stability and second, it is free of toxic and volatile substances. Another important aspect is, it is self-foaming. In this study was investigated the overall kinetics of the reaction during the curing process of these polymer composites. An appropriate method for this experiment proved to be the DSC in isothermal and non-isothermal mode and MDSC. This turned out to be a safe quality control technique for these systems. Parallel to the non-isothermal and isothermal DSC conductivity measurements have been performed to determine the end point of the curing reaction
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Amann, Jean-Marc. "Etude de procédés de captage du CO2 dans les centrales thermiques." Phd thesis, École Nationale Supérieure des Mines de Paris, 2007. http://pastel.archives-ouvertes.fr/pastel-00003445.
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La présente étude a pour objectif d'évaluer et de comparer entre eux divers procédés de captage du CO2 appliqués aux centrales thermiques alimentées en gaz naturel (NGCC) et au charbon pulvérisé (CP). Ces procédés consistent en un captage du CO2 des fumées en post-combustion par des solvants chimiques, une décarbonisation du gaz naturel avec captage du CO2 en pré-combustion par un solvant physique et l'oxy-combustion du combustible avec séparation frigorifique du CO2. Ces procédés ont été évalués à l'aide du logiciel de procédés Aspen PlusTM pour aider à choisir la meilleure option pour chaque type de centrale. Pour la post-combustion, une solution aqueuse basée sur un mélange d'amines (N-méthyldiéthanolamine (MDEA) et triéthylène tétramine (TETA)) a été évaluée. Des mesures d'absorption ont été réalisées entre 298 et 333 K dans un réacteur fermé type cellule de Lewis. La pression partielle du CO2 à l'équilibre, caractéristique de la solubilité du CO2 dans le solvant, a été déterminée jusqu'à 393 K. Les performances sont comparées vis à vis de solvants plus conventionnels tels que la MDEA et la monoéthanolamine (MEA). Pour l'oxy-combustion, un procédé de captage, basé sur une séparation des composants des fumées à faible température, a été développé et appliqué aux centrales NGCC et CP. L'étude a montré que la pureté du flux d'O2 avait une influence non négligeable sur la concentration en CO2 dans les fumées et donc sur les performances du procédé de séparation. La dernière option étudiée est le reformage du gaz naturel qui permet un captage du CO2 en amont du système de production de l'électricité. Plusieurs configurations ont été évaluées : reformage à l'air ou à l'oxygène, pression de reformage et dilution du gaz de synthèse. La comparaison de ces différents concepts suggère que, à court et moyen terme, l'absorption chimique soit le procédé le plus intéressant pour la centrale NGCC. Pour la centrale CP, l'oxy-combustion peut être une option très intéressante, au même titre que le captage en post-combustion par absorption chimique.
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余建和, Jian-He Yu, and 余建和. "Characteristics of a New Photosensitizer (tetramino-zinc-phthalocyanine) and Its Cancer Cell Damage Effects." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/j2q59n.
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碩士<br>國立臺灣大學<br>光電工程學研究所<br>105<br>A new type of Pc-series photosensitizer, tetramino-zinc-phthalocyanine (ZnPcN), which can link with alpha-Thio-omega-carboxy poly(ethylene glycol) (HS-PEG-COOH) through covalent bonding, such that its linkage with an Au nanoparticle (NP) becomes stronger for reducing the escape rate is synthesized. After demonstrating its fundamental photosensitizer characteristics, its escape behavior is compared with that of the commonly used PcS-series photosensitizer, tetrasulfonate-aluminum-phthalocyanine (AlPcS), through the measurements of the decreasing trends of absorption and cell damage efficiency with increasing waiting time. It is found that the escape of ZnPcN is indeed slower than that of AlPcS. For ZnPcN, the cell damage efficiency decreases most significantly in the first 10 min of waiting and saturates 30 min after incubation. However, for AlPcS, the cell damage efficiency keeps decreasing with waiting time up to 4 hours after incubation. The stronger chemical bonding between ZnPcN and HS-PEG-COOH leads to less ZnPcN escape and hence a longer waiting time of high cell damage capability, when compared with the electro-static bonding between AlPcS and HS-PEG-NH2.
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Su, Jia-Yi, and 蘇家誼. "A New Approach to Chiral Tetramic Acid Derivatives." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/k5w7dq.
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Katzka, Catherine P. [Verfasser]. "Synthesis of tetramic acids and investigation of their biological properties / von Catherine P. Katzka." 2006. http://d-nb.info/997869550/34.
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Schab-Balcerzak, Ewa. "Badania nad nowymi semidrabinkowymi polimerami." Rozprawa doktorska, 1998. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=3080.
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Schab-Balcerzak, Ewa. "Badania nad nowymi semidrabinkowymi polimerami." Rozprawa doktorska, 1998. https://delibra.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=3080.
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Melanophy, Claire [Verfasser]. "Keteneylidenetriphenylphosphorane as a C2O building block in the synthesis of highly functionalised tetramic and tetronic acids / vorgelegt von Claire Melanophy." 2004. http://d-nb.info/972529942/34.
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