Splitting of low rank ACM bundles on hypersurfaces of high dimension

Let $X$ be a smooth projective hypersurface. In this note we show that any rank 3 arithmetically Cohen-Macaulay vector bundle over $X$ splits when dim $X \geq 7$. We also find a splitting criterion for rank 4 arithmetically Cohen-Macaulay vector bundles on $X$ when dim $X \geq 9$

TOWARDS THE UNDERSTANDING OF THE EFFECT OF FUNCTIONAL MONOMERS ON LATEX PARTICLE MORPHOLOGY FORMED BY EMULSION POLYMERIZATION

Emulsion polymerization is a multiphase reaction process and the overall kinetics depend on the reaction rates in both the aqueous and particle phases. The morphology development within composite latex particles is controlled by both kinetic and thermodynamic factors. Functional monomers like acrylic acid and 2-hydroxyethyl methacrylate are widely used in emulsion polymerization at low concentrations (usually \u3c 10% to total monomers) to improve various properties like shear and freeze thaw stability of the latex, adhesion of the polymer to metal and paper, and to create the possibility for post-polymerization chemical modifications. These monomers are highly water soluble and very much more polar than the commonly used acrylate and styrene monomers. This dissertation deals with the effect of such functional monomers on the reaction kinetics during the emulsion polymerization and on the resulting morphology of the composite latex particles. A detailed examination of the distribution behavior of vinyl acid and hydroxy (meth)acrylate functional monomers between the nonfunctional monomer phase and the aqueous phase is reported here. Due to the dimerization and multimer formation capabilities of vinyl acid and hydroxy (meth)acrylate monomer via hydrogen bonding, the distribution of these monomers between aqueous and organic phases can be highly concentration dependent. In addition, the distribution of vinyl acids is a strong function of pH. Common emulsion polymerization with functional monomers uses more than one nonfunctional monomer. We found that the distribution of functional monomers can be effectively predicted for multicomponent nonfunctional monomer mixtures using appropriate `mixing rules\u27. The distribution of a monomer between the aqueous phase and the polymer particle phase is normally estimated using monomer-polymer Flory-Huggins interaction parameters and we have carefully determined such parameters for the functional monomers and various polymers examined in this work. From the experimental and simulation studies for seeded emulsion copolymerizations with functional monomers, we found that both the aqueous phase and the particle phase kinetics are affected by these monomers. The functional monomers produced longer oligoradicals (Z-mers) in the water phase which then entered the particles to promote polymerization. Moreover, the distribution studies revealed an increase in the water phase monomer concentrations when these functional monomers were present. Both of these phenomena combined to result in an increase in the radical entry rate into the particles as compared to reactions without functional monomers under similar conditions. The particle morphologies obtained from seeded emulsion polymerizations with functional monomers were characterized and compared to those without the functional monomers. In these studies the levels of the functional monomers were varied between 0% and 10% and the polarity differences between the seed and second stage polymers changed in different directions depending on the particular system. For all of the systems studied, it was found that for the cases where the final particle morphology was either at or close to equilibrium (in terms of the minimization of free energy), the incorporation of the functional monomers did not impact the morphology significantly. However for the cases where the final morphologies were kinetically controlled, increases in the amount of functional monomer in a nonpolar second stage monomer increased the amount of phase mixing with a polar seed polymer

Dogielius kaelensis n. sp. (Monogenea, Dactylogyridae), a gill parasite of Garra annandalei Hora, 1921 (Cyprinidae, Labeoninae) in Arunachal Pradesh, India

Parasite biodiversity of fish in Arunachal Pradesh of northeast India is still unexplored. We describe here a new species of Dogielius (Monogenea: Dactylogyridae) from the gill filaments of Garra annandalei(Cyprinidae), collected from the River Kael, Arunachal Pradesh. Dogielius kaelensis n. sp. is distinguished from its congeners by two key features: (i) a robust ventral bar with a medial part twisted forward, and ii) an accessory piece with a ring to help guide the copulatory tube. This is only the second time a member of the genus Dogielius has been found parasitizing a Garra species

Understanding the order effect of online review sentiments and product features

Online reviews have played an increasingly important role in the popularity and success of e-commerce (Yin et al. 2014). The decreasing digital divide and ubiquitous internet access, along with the proliferation of smart mobile devices, have resulted in an exponential increase in the online purchase of goods and services. Additionally, customers are encouraged and incentivized to share their personal experiences using the product or service. Such experiences represented on internet platforms are captured through electronic word-of-mouth, typically in the form of online reviews. Prior studies on online reviews have shown that the experience of consumers plays an important role as an information source when potential consumers make purchasing decisions (Luo et al. 2013). Researchers have also revealed that opinion mining and sentiment analysis of online reviews can be used to predict the pricing power (Archak et al. 2011) and sales (Chevalier and Mayzlin 2006; Gu et al. 2012) of the product