Approximate analytical lower bounds on ‘double asymptotic scaling’ variables and physics at HERA

We analytically examine the asymptotic solution of gluon evolution equation in terms of the ‘double scaling variables’ρ andσ of perturbative QCD and find the approximate lower bounds on these, above which the solution is considered to be valid. Comparison of this asymptotic solution is made with the fit obtained from data and the estimated lower bound onρ is nearly equal to our analytical finding. To analyze the data below the lower bound onρ, other analytical solutions of gluon evolution equation are to be used which depend highly on the inputx-distributions of gluon to study the physics at low-x of HERA range.     

Adsorption affinity of certain biomolecules onto polymeric resins: Interpretation from molecular orbital theory

Molecular interactions have been studied for adsorption of certain biomolecules in aqueous solutions using two different types of polymeric resins as adsorbents. Molecular modeling study is based on molecular orbital theory. Adsorption affinity expresses as the slope of the linear region of the isotherm for a solute is found to be different for different adsorbents, and this difference can be interpreted from the differences in sorbent surface chemistry and morphological structure. The adsorptive interaction on the polymeric resins computed on the basis of frontier orbital theory seems to correlate well with the experimentally measured adsorption affinity. Electronic states of adsorbent and adsorbate were calculated using the semiempirical molecular orbital (MO) method from which energy of adsorption in aqueous solution was estimated. It was found that charge transfer interaction plays an important role in the adsorption of certain biomolecules on aqueous solution. The experimentally measured enthalpy of adsorption seems to correlate well with the adsorptive interaction energy computed from molecular orbital theory.     

Preparation of a novel 16-DPA-P2S5 adduct and its application as a masked α,β-unsaturated ketone in [4+2]cycloaddition reactions

The reaction of 16-DPA with P₄S₁₀ in refluxing benzene afforded a novel adduct 16-DPA-P₂S₅ instead of the expected thione. The adduct undergoes [4+2]cycloaddition with alkyne dienophiles to afford steroidal (17,16-c)pyrans.     

A validated high‑performance thin-layer chromatography method for the simultaneous determination of quercetin and gallic acid in Annona reticulata L.

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive and reliable high-performance thin-layer chromatography (HPTLC) method has been developed to simultaneously estimate...     

Block copolymers based on 2‐vinyl‐4,4‐dimethyl‐5‐oxazolone by RAFT polymerization: Experimental and computational studies

The ability of 2‐vinyl‐4,4‐dimethyl‐5‐oxazolone (VDM), a highly reactive functional monomer, to produce block copolymers by reversible addition fragmentation chain transfer (RAFT) sequential polymerization with methyl acrylate (MA), styrene (S), and methyl methacrylate (MMA) was investigated using cumyl dithiobenzoate (CDB) and 2‐cyanoisopropyl dithiobenzoate (CPDB) as chain transfer agents. The results show that PS‐b‐PVDM and PMA‐b‐PVDM well‐defined block copolymers can be prepared either by polymerization of VDM from PS‐ and PMA‐macroCTAs, respectively, or polymerization of S and MA from a PVDM‐macroCTA. In contrast, PMMA‐b‐PVDM block copolymers with controlled molecular weight and low polydispersity can only be obtained by using PMMA as the macroCTA. Ab initio calculations confirm the experimental studies. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Numerical analysis of detonation combustion wave in pulse detonation combustor with modified ejector with gaseous and liquid fuel mixture

Journal of Thermal Analysis and Calorimetry - The detonation combustion phenomenon is supersonic combustion process and follows on thermal explosion in combustor. Deflagration to detonation...     

Facile synthesis of highly luminescent ZnSe(S) alloyed quantum dot for biomedical imaging

An alloyed complex of zinc, sulphur and selenium was synthesized in a controlled fashion using 3-mercaptopropionic acid (MPA) surfactant to obtain a new class of biocompatible, highly luminescent imaging probes. These ZnSe(S) alloyed quantum dots (QDs) exhibited a five fold enhancement in photoluminescence over the native ZnSe nanocrystals. The enhancement in photoluminescence was brought about without any post-preparative surface treatments, under ambient conditions. 3-mercaptopropionic acid (MPA) was found to optimally stabilize the ZnSe(S) alloyed system. The incorporation of S^2? from MPA after prolonged refluxing time enabled the formation of ZnSe(S) alloyed QDs with low cytotoxicity. The in vitro assays revealed the synergistic enhancement of photoluminescence with enhancement in dispersibility and high biocompatibility for the ZnSe(S) system. The experimental findings give us a novel range of blue-emitting, Zn-based high luminescence QDs for development of nano-probes for bioimaging applications.     

Explicit evaluations of Ramanujan-Göllnitz-Gordon continued fraction

In this paper, we establish several theorems for the explicit evaluations of Ramanujan-G?llnitz-Gordon continued fraction by using some parameterizations of Ramanujan’s theta-functions. Nayandeep Deka Baruah, Corresponding author. Research partially supported by grant SR/FTP/MA-02/2002 from DST, Govt. of India. Authors’ address: Nayandeep Deka Baruah and Nipen Saikia, Department of Mathematical Sciences, Tezpur University, Napaam-784028, Assam, India     

Diastereoselective synthesis of substituted tetrahydrothiopyrans via (3,5)-thionium-ene cyclization reaction

Tetrahydrothiopyrans have been efficiently synthesized in good yields with excellent diastereoselectivity from aldehydes and substituted 5-methylhex-4-ene-1-thiol via (3,5)-thionium-ene cyclization reaction mediated by boron trifluoride etherate.