in this work, new biodegradable abcba type pentablock copolymers with different mole ratio of l-lactide and ppdo-b-peg-b-ppdo triblock copolymer were synthesized and characterized. in the first step, ppdo-b-peg-b-ppdo triblock copolymer was synthesized via a ring-opening polymerization of p-dioxanone (pdo) monomer with poly (ethylene glycol) (peg) using stannous octoate (sn(oct)2) as the cataly...

Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length ...

This study proposes the SCRATCH model for the aqueous solubility estimation of a compound directly from its structure. The algorithm utilizes predicted melting points and predicted aqueous activity coefficients. It uses two additive, constitutive molecular descriptors (enthalpy of melting and aqueous activity coefficient) and two non-additive molecular descriptors (symmetry and flexibility). Th...

Walter Kauzmann's classic 1948 review of liquid supercooling and glass formation drew attention to the temperatures at which (by extrapolation) enthalpies and entropies of liquid and crystal phases would appear to become equal. In the temperature-pressure (T, p) plane, the collection of such 'Kauzmann temperatures' generate characteristic curves. The present study examines the connection of tho...

We report melting points and other thermal properties of several semiconducting and metallic elements as they are modelled by different empirical interatomic potential models, including Stillinger-Weber (SW), embedded-atommethod (EAM), Finnis-Sinclair (FS) and modified-embedded-atom-method (MEAM). The state-of-the-art free energy methods are used to determine the melting points of these models ...

Solid-state compatibility and melting relationships in the subsystem Al2O3–MgAl2O4–CaAl4O7 were studied by firing and quenching selected samples located in the isopletal section (CaOzMgO)–Al2O3. The samples then were examined using X-ray diffractomtery, optical microscopy, and scanning and transmission electron microscopies with wavelengthand energy-dispersive spectroscopies, respectively. The ...

A variable temperature sample holder with an operational range of 15 to 200 °C and an accuracy of ±1 °C has been fabricated for scanning transmission X-ray microscopes (STXM). Here we describe the device, and use it to image the polycrystalline morphology of solid stearic acid and palmitic acid at temperatures near their respective melting points as a means of checking for possible sample heati...

Lamson et al. (1-8) carried out extensive studies on the anthelmintic activity of a large number of alkylhydroxybenzenes and found that substances which apparently act through the cuticle of ascaris were ineffective when their melting points were too high. Harwood (9) demonstrated that if such chemicals were kept in the liquid phase by adulteration with certain organic liquids, their in vitro a...