10,978 research outputs found

    Energy absorption by polymer crazing

    Get PDF
    During the past thirty years, a tremendous amount of research was done on the development of crazing in polymers. The phenomenon of crazing was recognized as an unusual deformation behavior associated with a process of molecular orientation in a solid to resist failure. The craze absorbs a fairly large amount of energy during the crazing process. When a craze does occur the surrounding bulk material is usually stretched to several hundred percent of its original dimension and creates a new phase. The total energy absorbed by a craze during the crazing process in creep was calculated analytically with the help of some experimental measurements. A comparison of the energy absorption by the new phase and that by the original bulk uncrazed medium is made

    Anisotropic Relaxation Functions and Strength of Oriented Solids Technical Report No. 106

    Get PDF
    Anisotropic relaxation functions and strength of oriented solid

    Extremal metrics for the Q′{Q}^\prime-curvature in three dimensions

    Full text link
    We construct contact forms with constant Q′Q^\prime-curvature on compact three-dimensional CR manifolds which admit a pseudo-Einstein contact form and satisfy some natural positivity conditions. These contact forms are obtained by minimizing the CR analogue of the IIII-functional from conformal geometry. Two crucial steps are to show that the P′P^\prime-operator can be regarded as an elliptic pseudodifferential operator and to compute the leading order terms of the asymptotic expansion of the Green's function for P′\sqrt{P^\prime}.Comment: Final version; Corrects minor typos; This is an announcement of the main results of arXiv:1511.05013; 5 page

    Anomeric O-Functionalization of Carbohydrates for Chemical Conjugation to Vaccine Constructs.

    Get PDF
    Carbohydrates mediate a wide range of biological interactions, and understanding these processes benefits the development of new therapeutics. Isolating sufficient quantities of glycoconjugates from biological samples remains a significant challenge. With advances in chemical and enzymatic carbohydrate synthesis, the availability of complex carbohydrates is increasing and developing methods for stereoselective conjugation these polar head groups to proteins and lipids is critically important for pharmaceutical applications. The aim of this review is to provide an overview of commonly employed strategies for installing a functionalized linker at the anomeric position as well as examples of further transformations that have successfully led to glycoconjugation to vaccine constructs for biological evaluation as carbohydrate-based therapeutics
    • …
    corecore