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An infra-red spectroscopic study of polyamidesHallos, Roger Stanley January 1979 (has links)
No description available.
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Nonlinear viscoelasticity of polyamide fibersKo, Frank Koon-Fun January 1976 (has links)
No description available.
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Untersuchung flüchtiger Verbindungen bei der thermischen Zersetzung von stickstoffhaltigen PolymerwerkstoffenHerrera Salinas, Maclovio. January 2000 (has links) (PDF)
München, Techn. Universiẗat, Diss., 2001.
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Neue Polyamide aus niedermolekularen Kohlenhydraten Darstellung und Polykondensation von Monomerbausteinen aus Saccharose, D-Glucose, D-Fructose, D-Galactose und Isomaltulose /Vlach, Andreas. Unknown Date (has links)
Techn. Universiẗat, Diss., 2001--Darmstadt.
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Modélisation du comportement mécanique des engrenages en polymère / Mechanical behaviour model in the case of polymer cylindrical gearsLetzelter, Eric 10 February 2011 (has links)
Les engrenages en matériau polymère sont de plus en plus utilisés dans des domaines variés, notamment dans des applications automobiles, où il est courant de trouver des engrènements polymère / métal ou polymère / polymère. Pour bon nombre d’applications, les polymères choisis pour réaliser des engrenages moulés ou taillés sont des semi-cristallins de type polyamides (nylon). Néanmoins, leur caractère viscoélastique introduit une difficulté supplémentaire dans la modélisation. En effet, le comportement viscoélastique des polymères dépend de la température et de la vitesse de rotation. Pour les Polyamides, il dépend également de l’humidité. Par conséquent, la viscoélasticité peut influencer la répartition des charges, l’erreur de transmission sous charge, la raideur d’engrènement… Dans cette thèse, une méthode numérique originale modélisant le comportement mécanique des engrenages en Polyamide 6,6 est proposée. L’approche développée utilise le modèle rhéologique linéaire de Kelvin généralisé pour simuler le comportement viscoélastique du matériau et prendre en compte la température, la vitesse de rotation et l’humidité. Ensuite ce modèle rhéologique est intégré dans le modèle quasi-statique du partage des charges développé par le LaMCoS. Ce processus de calcul permet d’obtenir les résultats essentiels pour les engrenages (répartition des charges, pressions de contact, erreur de transmission sous charge, raideur d’engrènement) avec un temps de calcul assez court. Enfin, un banc expérimental avec des engrenages en Polyamide 6,6 est développé et fabriqué dans le cadre de cette thèse. Il permet d’obtenir deux résultats : la température de l’engrenage pendant son fonctionnement et l’erreur de transmission sous charge. Cette dernière permet de valider le modèle quasi-statique du partage des charges. / Polymer gears are increasingly used, especially in automotive applications, where it is common to find meshing polymer / metal or polymer / polymer.For many applications, the polymer selected to produce gears by cutting or by injection moulding is polyamide (nylon) which has semi-crystalline structure. However, the viscoelastic character of Polyamide material introduces an additional difficulty in modeling. Indeed, the viscoelastic behavior of polymers is temperature and rotation speed dependent. In addition for polyamides, it also humidity dependent. Therefore, viscoelasticity influences the load sharing, the load transmission error, the meshing stiffness... In this thesis, an original numerical method modeling the mechanical behavior of polyamide 6.6 gears is proposed. This approach uses the linear rheological model of generalized Kelvin to simulate the viscoelastic behavior of the material and take into account the temperature, speed and humidity. The rheological model is integrated into the quasi-static load sharing model developed by the LaMCoS. This process provides the essential results for gears (load sharing, contact pressure, load transmission error, meshing stiffness) with short computation time. Finally, an experimental test bench with Polyamide 6.6 gears is developed. It provides two experimental results: the temperature of the gear during operation and the load transmission error which validates the quasi-static load sharing model
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Helicing Polyamide for DNA BindingLee, Kun-da 10 August 2007 (has links)
Aromatic oligoamide foldamers possess a high potential for mimicking the secondary structures of biopolymers. These oligomers are efficiently designed, easy to synthesize, and allow one to reach a wide range of stable folded states.Thus far, we want to utilize stable states of these oligomers and a variety of groove binding agents combining together , and then study their influence on DNA.
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DNA Sequence Selective Recognition: Synthesis of Azo- and Diimine CompoundsLiu, Ping-Hao 01 August 2004 (has links)
Polyamide containing groove binding agents have been widely reported We now synthesized netropsin analogs containing azo¡Bimine and diimine functional groups in place of the amide functionality and study their biological activities. Some of these analogs were found to have cytotoxicity in the range of 5 g/mL.
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DNA Sequence Selective Recognition:Synthesis of Urea CompoundsLiu, Meng-chi 11 July 2005 (has links)
Polyamide containing groove binding agents have been widely reported We now synthesized netropsin analogs containing urea groups in place of the amide functionality and study their biological activities.
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synthesis of bipyrrole-pyrrolidineLin, Chun-yu 25 July 2008 (has links)
Polyamide containing groove binding agents have been widely reported. We synthesized pyrrolidine to displace one of pyrrole of distamycin, and research into structure which was effected by optical and saturated heterocycle.
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FATE OF REVERSE OSMOSIS (RO) MEMBRANES DURING OXIDATION BY DISINFECTANTS USED IN WATER TREATMENT: IMPACT ON MEMBRANE STRUCTURE AND PERFORMANCESMaugin, Thomas 12 1900 (has links)
Providing pretreatment prior RO filtration is essential to avoid biofouling and
subsequent loss of membrane performances. Chlorine is known to degrade polymeric
membrane, improving or reducing membrane efficiency depending on oxidation
conditions. This study aimed to assess the impact of alternative disinfectant, NH2Cl,
as well as secondary oxidants formed during chloramination of seawater, e.g. HOBr,
HOI, or used in water treatment e.g. ClO2, O3, on membrane structure and
performances. Permeability, total and specific rejection (Cl-, SO4
2-, Br-, Boron), FTIR
profile, elemental composition were analyzed. Results showed that each oxidant
seems to react differently with the membrane. HOCl, HOBr, ClO2 and O3 improved
membrane permeability but decreased rejection in different extent. In comparison,
chloramines resulted in identical trends but oxidized membrane very slowly. On the
contrary, iodine improved membrane rejection e.g. boron, but decreased permeability.
Reaction conducted with chlorine, bromine, iodine and chloramines resulted in the
incorporation of halogen in the membrane structure. All oxidant except iodine were
able to break amide bonds of the membrane structure in our condition. In addition,
chloramine seemed to react with membrane differently, involving a potential addition
of nitrogen. Chloramination of seawater amplified membrane performances evolutions
due to generation of bromochloramine. Moreover, chloramines reacted both with
NOM and membrane during oxidation in natural seawater, leading to additional
rejection drop.
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