Electron impact total cross section calculations for CH3SH (methanethiol) from threshold to 5 keV

We report calculated total elastic cross sections Q_el, total ionisation cross sections, Q_ion, summed total excitation cross sections ∑Q_exc and total cross sections Q_T for CH₃SH upon electron impact for energies from ionisation threshold to 5 keV. We have employed Spherical Complex Optical Potential (SCOP) formalism to calculate total elastic cross section Q_el, and total inelastic cross section Q_inel and used Complex Scattering Potential – the ionisation contribution (CSP-ic) method to extract the ionisation cross sections, Q_ion, from the calculated Q_inel. The calculated total cross sections are examined as functions of incident electron energy and are compared with available data wherever possible and overall good agreement is observed. In this work Q_el, Q_ion, and ∑Q_exc are reported for the first time for CH₃SH in this energy range.     

Biosorptive profile of synthetic and natural humiresin for the remediation of metallic water pollutants

To evaluate the bioremediation efficiency of natural humic substances, over it’s synthetic counterpart, a comparative batch equilibration biosorption assay have been carried out employing radiotracers on different humi-resins. The biosorptive profile of various humiresins as devised hereby, attempts to justify an innovative and concrete role of dry cow dung powder (DCP), in ‘as it is form’, for the bioremediation of metal pollutants such as Cr(III), Cr(VI), Cd(II), Hg(II) and Sr(II). Our comparative results conclude that, with all other optimized parameters as obtained 100 mg of DCP removes Cr(III) at pH 6, Cd(II) at pH 3 and Hg(II) at pH 3 to 70–75 and 80–85 % respectively. Also, at pH 1 with 250 mg of DCP 70–75 % Cr(VI) is removed. Similarly, 90–95 % of Sr(II) is sequestered at pH 6, with 350 mg of DCP. The study on thermodynamic, kinetic and isotherm modelling of DCP indicates feasible, eco-friendly and efficient process.     

The Grothendieck group of a cluster category

For the cluster category of a hereditary or a canonical algebra, or equivalently for the cluster category of the hereditary category of coherent sheaves on a weighted projective line, we study the Grothendieck group with respect to an admissible triangulated structure.     

From iterated tilted algebras to cluster-tilted algebras

In this paper the relationship between iterated tilted algebras and cluster-tilted algebras and relation extensions is studied. In the Dynkin case, it is shown that the relationship is very strong and combinatorial.     

Generalized Serre relations for Lie algebras associated with positive unit forms

Every semisimple Lie algebra defines a root system on the dual space of a Cartan subalgebra and a Cartan matrix, which expresses the dual of the Killing form on a root base. Serre’s Theorem [J.-P. Serre, Complex Semisimple Lie Algebras (G.A. Jones, Trans.), Springer-Verlag, New York, 1987] gives then a representation of the given Lie algebra in generators and relations in terms of the Cartan matrix.In this work, we generalize Serre’s Theorem to give an explicit representation in generators and relations for any simply laced semisimple Lie algebra in terms of a positive quasi-Cartan matrix. Such a quasi-Cartan matrix expresses the dual of the Killing form for a Z-base of roots. Here, by a Z-base of roots, we mean a set of linearly independent roots which generate all roots as linear combinations with integral coefficients.     

Modeling the film casting process using a continuum model for crystallization in polymers

In this paper, the film casting process has been simulated using a new model developed recently using the framework of multiple natural configurations to study crystallization in polymers (see Rao and Rajagopal Z. Angew. Math. Phys. 53 (2002) 265; Polym. Eng. Sci. 44(1) (2004) 123; Simulation of the film blowing process for semicrystalline polymers, in press, 2004). In the film casting process, the material starts out as a viscoelastic melt and undergoes deformation and cooling, resulting in a semi-crystalline solid. In order to model the complex changes taking place in the material and predict the behavior of the final solid it is important to use models that are capable of describing these changes. The model used here has been formulated within a general thermodynamic framework that is capable of describing dissipative processes. In addition it handles in a direct manner the change of symmetry in the material; it thus provides a good basis for studying the crystallization process in polymers. The polymer melt is modeled as a rate type viscoelastic fluid and the crystalline solid polymer is modeled as an anisotropic elastic solid. The initiation criterion, marking the onset of crystallization and equations governing the crystallization kinetics arise naturally in this setting in terms of the appropriate thermodynamic functions. The mixture region, wherein the material transitions from a melt to a semi-crystalline solid, is modeled as a mixture of a viscoelastic fluid and an elastic solid. This is in marked contrast to earlier approaches where in the simulation has been done assuming that the material was a viscous fluid and the transition to a solid like behavior is achieved by increasing the viscosity to a large value resulting in a highly viscous fluid and not an elastic solid. The results of our simulations compare well against experimental data available in literature. In addition to these quantitative comparisons have carried out parametric study to study the influence of the different parameters on the film casting process.     

Representation-finite derived tubular algebras

The use of quadratic forms as a tool for characterizing classes of algebras is well known and widely accepted. However, until now a characterization of the interesting class of derived tubular algebras, by properties of the (non-symmetric) Euler form only, failed because of the existence of so-called pg-critical algebras, whose Euler form manifest similar properties as those of tubular algebras. The present article fills this gap and provides a distinction between derived tubular algebras and derived pg-critical algebras. Furthermore, an explicit characterization of representation-finite derived tubular algebras in terms of their Euler forms will be given.     

Total cross-section calculations for electrons colliding with molecular nitrogen over an extensive energy range from meV to keV

We report a comprehensive study of the electron impact total cross-sections for molecular nitrogen for impact energies from 0.01?eV to 2000?eV. Ab initio calculations are performed using the R-matrix formalism at low impact energies (up to ～15?eV), while the Spherical Complex Optical Potential formalism is utilised beyond this range. The two methods are consistent at the transition energy, which enables us to provide data for such an extensive range. The results obtained show overall good agreement with the available data.     

Ability of simple organotin polyethers to inhibit pancreatic cancer

A wide variety of organotin polyethers derived from the interfacial polymerization of dibutyltin dichloride and non-cancer inhibitory diols show decent to good inhibition of two human pancreatic cancer cell lines. In view of the general lack of ability of tested compounds to inhibit pancreatic cancer cell lines, this is significant. These cell lines are the AsPC-1 pancreatic cancer cell line which is an adenocarcinoma pancreatic cell line and the PANC-1 pancreatic cancer cell line which is an epithelioid carcinoma pancreatic cell line. The dibutyltin polyethers generally both exhibit EC₅₀ values in the same range and lower than cisplatin and higher CI₅₀ values than cisplatin. Essentially all of the polymers derived from simple non-aromatic diols showed CI₅₀ values greater than 2.     

Aldol dimerization of 1-indanone and 1-tetralones

The aldol dimerization of 1-indanone and 1-tetralones using titanium tetrachloride and triethylamine as condensing agents provides α,β- and β, γ-unsaturated ketones, respectively, in 53–58% yield.