Effective Sidewall Functionalization of Multiwalled Carbon Nanotubes with Dichlorocarbene Addition using New Soluble Multi-site Phase Transfer Catalysts

The novel soluble multi-site phase transfer catalysts (MPTCs), viz., 2,6-bis (triethylammoniummethylene chloride)-4-methoxytoluene (BTEACM) and 3,3’,5,5’-tetrakis (dimethylaminopyridinium chloride) biphenyl (TDMAPCB) containing two, and four active sites was synthesized, and characterized through Fourier transform infra red spectroscopy (FTIR), proton nuclear magnetic spectroscopy, carbon nuclear magnetic spectroscopy, thermo gravimetric analysis (TGA) and energy dispersive spectroscopy (EDS) analyses. The obtained MPTCs were used as a catalysts for sidewall functionalization of multiwalled carbon nanotubes (MWCNTs) in dichlorocarbene (CCl2) addition, and compared their functionalization yield with commercially available single site PTC and tri-site PTC viz., benzyltriethylammonium chloride (BTEAC) and 2,4,6-tris (triethylammoniummethylene chloride) mesitylene (TTEAMCM). The functionalization of CCl2 on MWCNTs was established by the appearance of increased peak intensity of C-Cl(str) at 700 cm-1 and decreased peak intensity of C-C(str) at 1260 cm-1 in FTIR analysis. The increased ID/IG ratio from pristine MWCNTs (0.3) to MWCNT-CCl2 hybrid (1.58) obtained from Raman studies strongly proved the covalent functionalization of CCl2 on MWCNTs. Furthermore, the change of surface morphology, and increased diameter of MWCNT-CCl2 hybrids obtained from irrespective of MPTCs were confirmed by scanning electron microscopy, high resolution transmission electron microscopy, and atomic force microscopy. Hence, TDMAPCB showed higher reactivity for sidewall functionalization of MWCNTs in CCl2 addition

Inheritance studies through generation mean analysis for quantitative traits in soybean (Glycine max (L.) Merrill.)

Most of the economically important traits in soybean are quantitatively inherited. The generation mean analysis involving a five-parameter model was carried out in four crosses, viz., Pratap Soya- 2 × LP 5-2, Co 3 × LP 5-2, Co 3 × LP 5-1 and Co 3 × LP 13-1 to investigate additive, dominance and epistatic variance. Therefore, F1, F2 and F3 generations of the above four crosses were evaluated along with their respective parents to estimate the gene action for eleven quantitative traits through generation mean analysis, which provides information about all the gene interactions. The crosses Co 3 × LP 5-1 and Co 3 × LP 13-1 for plant height, Pratap Soya-2 × LP 5-2 for protein content and Co 3 × LP 5-2 for both oil content and seed yield per plant exhibited the adequacy of the additive dominance model. The remaining crosses exhibited epistatic interactions with all other traits. Hence simple recurrent selection can be followed to increase the frequency of desirable genes in the population and the resulted improved population can be used to develop superior lines with desirable genes by pedigree breeding. The crosses Co 3 × LP 5-1 and Pratap Soya - 2 × LP 5-2 were best for further selection programmes with regard to seed yield and quality improvement

Arsenic removal using silver-impregnated Prosopis spicigera L. wood (PSLW) activated carbon: batch and column studies

Silver-impregnated carbon (SIC) and its precursor (un-impregnated) derived from an easily available low cost plant material Prosopis spicigera L. wood (PSLW) carbon was investigated for their ability to remove arsenic from aqueous solutions in batch and column experiments. Arsenic uptake has no regular trend with increasing pH; contains two adsorption maxima, the first adsorption maximum at pH 4.0 and a second adsorption maximum at pH 10.0. The extent of As (III) removal increased with increase in temperature. As (III) sorption kinetics was well fitted by pseudo second order with pore diffusion as rate determining step. The applicability of Langmuir isotherm suggests the formation of monolayer coverage of As (III) at the outer surface of the adsorbent. Thermodynamic parameters show that the adsorption was spontaneous and endothermic in nature. Column experiments were done using Thomas model, the maximum adsorption capacity of SIC was found to be 9.36 mg/g.Keywords: Adsorption, Arsenic, batch adsorption, langmuir isotherm, silver-impregnated carbon (SIC), Thomas mode

Transmogrifying Fuzzy Vortices

We show that the construction of vortex solitons of the noncommutative Abelian-Higgs model can be extended to a critically coupled gauged linear sigma model with Fayet-Illiopolous D-terms. Like its commutative counterpart, this fuzzy linear sigma model has a rich spectrum of BPS solutions. We offer an explicit construction of the degree$-k$ static semilocal vortex and study in some detail the infinite coupling limit in which it descends to a degree$-k$ \C\Pk^{N} instanton. This relation between the fuzzy vortex and noncommutative lump is used to suggest an interpretation of the noncommutative sigma model soliton as tilted D-strings stretched between an NS5-brane and a stack of D3-branes in type IIB superstring theory.Comment: 21 pages, 4 figures, LaTeX(JHEP3

A study on water hyacinth Eichhornia crassipes as oil sorbent

The sorption of diesel, lubricant and castor oils onto different parts (root, stem and leaf) of the dry biomass water hyacinth was studied at the laboratory scale. The parts of the aquapyte water hyacinth (Eichhornia Crassipes) were characterized by physico-chemical methods and the characteristics were used to elucidate the oil sorption process. Hydrophobicity, wettability (capillarity), buoyancy and sorption capacity of oils in the presence/absence of water were studied to evaluate the suitability of the sorbent for application. In all the three sorbents, theoil sorption capacity increases with the increase of oil film thickness. However of the three parts, the stem has a greater sorption capacity of 9.3, 7.8 and 11.08 g/g for the three oils such as diesel, lubricant and castor oils respectively, even though the root of water hyacinth showed a higher hydrophobicity and surface area. These sorption capacities are comparable with widely used commercial oil sorbent such as nonwoven polypropylene which has a sorption capacity in the range of 10-16 g/g

Designing efficient metal complex catalysts for acylation: A comparative study with soluble and insoluble catalysts systems

New soluble and insoluble Nb, Ta, Mo, and Sb complex catalysts have been developed using pyridine and polymersupported cross-linked (poly-4-vinyl pyridine) bead (PSCPVP), and characterized using FT-IR, SEM, EDAX, elemental analysis (CHN), and TGA. Their ability to catalyze the acylation of ethanol with acetic anhydride at 303K has been proven. Both soluble and insoluble chemicals have the same order of activity: MoCl5, TaCl5, NbCl5, and SbCl5. The insoluble catalyst outperformed in terms of activity by complex catalysts, although they have significant limitations in terms of solubility and recyclability and soluble homogeneous catalysts in terms of lowest cost and recyclability, whereas all soluble Py-MCl5 catalysts exhibit better activity than insoluble PSCPVP-MCl5 catalysts according to the computed kobs values. Insoluble catalysts are preferable than soluble homogeneous catalysts in terms of recyclability, although all the soluble catalysts of Py-MCl5, M= Nb, Ta, Mo, and Sb have exhibited better activity than insoluble PSCPVP-MCl5 (kobs= 6.51, 6.98, 7.48 & 1.73 x103 min-1) based on the computed kobs values. For acylation process, it has been found that the soluble Py- NbCl5, Py-TaCl5, Py-MoCl5, and Py-SbCl5 catalysts whereas 1.47, 1.63, 1.59, and 1.67 folds more active than PSCPVPNbCl5, PSCPVP-TaCl5, PSCPVP-MoCl5, and PSCPVP-SbCl5 correspondingly

Electrochemical determination of caffeine in beverage using graphene oxide modified glassy carbon electrode

528-536Graphene oxide (GO) has been synthesized through simple experimental method and used for surface modification of glassy carbon electrode, thus developed a new efficient GO/GCE as a sensor for identification and quantification of Caffeine in beverage samples. Common analytical techniques have been employed to establish the physiochemical properties of graphene oxide. The electro catalytic activity GO/GCE has been examined towards sensing and quantification of caffeine through Cyclic voltammetry and Differential pulse voltammetry. The results show high sensitivity with a wide linear range in concentration 3.2-183 µM and low detection limit (LOD) 0.043 µM. In addition, in order to inspect the real time application of GO/GCE, it has been also employed to determine the concentration of caffeine in cola, Red bull and coffee samples.Very low LOD has been observed for caffeine even in real sample analysis and hence this electrode can very well be expended for real time application and thus enable to maintain the quality control of the food samples

A high-affinity antibody against the CSP N-terminal domain lacks Plasmodium falciparum inhibitory activity

Malaria is a global health concern and research efforts are ongoing to develop a superior vaccine to RTS,S/AS01. To guide immunogen design, we seek a comprehensive understanding of the protective humoral response against Plasmodium falciparum circumsporozoite protein (PfCSP). In contrast to the well-studied responses to the repeat region and the C-terminus, the antibody response against the N-terminal domain of PfCSP (N-CSP) remains obscure. Here, we characterized the molecular recognition and functional efficacy of the N-CSP-specific monoclonal antibody 5D5. The crystal structure at 1.85 Åresolution revealed that 5D5 binds an α-helical epitope in N-CSP with high affinity through extensive shape and charge complementarity, and the unusual utilization of an N-linked glycan. Nevertheless, functional studies indicated low 5D5 binding to live Pf sporozoites, and lack of sporozoite inhibition in vitro and in mosquitoes. Overall, our data on low recognition and inhibition of sporozoites do not support the inclusion of the 5D5 epitope into the next generation of CSP-based vaccines.Summary Statement The Plasmodium falciparum sporozoite surface protein, PfCSP, is an attractive vaccine target, but the antibody response against the CSP N-terminal domain has remained understudied. Here, to guide immunogen design, Thai et al. provide insights into the binding motif and functional efficacy of the N-terminal domain-specific monoclonal antibody, 5D5