Local convergence analysis of the Gauss–Newton method under a majorant condition

AbstractThe Gauss–Newton method for solving nonlinear least squares problems is studied in this paper. Under the hypothesis that the derivative of the function associated with the least square problem satisfies a majorant condition, a local convergence analysis is presented. This analysis allows us to obtain the optimal convergence radius and the biggest range for the uniqueness of stationary point, and to unify two previous and unrelated results

Carbon Nanotube Doped Tellurite Glasses

In the past it was observed that buck ball doped glasses showed enhanced optical nonlinearities. However, carbon nanotubes are much more stable than buck ball and should be a better choice for that purpose. Therefore we decided to investigate the possibility to produce carbon nanotubes doped tellurite glasses and measured their optical nonlinearities. Tellurite glasses already have a larger nonlinearity compared to silica, and other, glasses. We produced TeO 2-ZnO tellurite family glasses doped with multi wall Carbon Nanotube (CNT). The CNTs acquired from Carbolex were vigorously mechanically mixed with the tellurite glass precursors and melted in platinum crucible around 650°C in a controlled atmosphere inside an electrical induction furnace. We used the lowest temperature possible and controlled atmosphere to avoid the CNT oxidation. The glass melt was cast in a stainless steel and thermally treated at 300°C for 5 hours to relieve internal stresses. The samples were than cutted and polished to perform the optical characterization. We measured refractive index and thermo physical properties, such as vitreous transition Tg, crystallization onset Tx and melting Tf temperatures. Raman spectroscopy showed the possible presence of CNTs.6890Iijima, S., (1991) Nature, 354, p. 56http://www.ati.surrey.ac.uk/news/n, onlinearDiMaio, J., Rhyne, S., Yang, Z., Fu, K., Czerw, R., Xu, J., Webster, S., Ballato, J., (2003) Information Sciences, 149, p. 69Aoki, Y., Okubo, S., Kataura, H., Nagasawa, H., Achiba, Y., (2005) Chem. Lett, 34 (4), p. 562Misra, S.K., Watts, P.C.P., Valappil, S.P., Silva, S.R.P., Roy, I., Boccaccini, A.R., (2007) Nanotechnology, 18, p. 07570

Pressure-induced radial collapse in few-wall carbon nanotubes: A combined theoretical and experimental study

Brazilian authors acknowledge funding from CNPq (grant 307317/2010-2, INCT NanoBioSimes) and Central Analítica-UFC/CT-INFRA-FINEP/Pró-Equipamentos-CAPES/CNPq-SisNano-MCTI (grant 402284/2013-5). R. S. Alencar is also in debt to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior under the grant No. 99999.004227/2014-00 for financial support. Alexander Soldatov (University of Lulea, Sweden) is warmly acknowledged for discussions on the RBM Raman spectra interpretation at the collapse region

Enhancing Biopharmaceutical Attributes of Phospholipid Complex-loaded Nanostructured Lipidic Carriers of Mangiferin: Systematic Development, Characterization and Evaluation

Mangiferin (Mgf), largely expressed out from the leaves and stem bark of Mango, is a potent antioxidant. However, its in vivo activity gets tremendously reduced owing to poor aqueous solubility and inconsistent gastrointestinal absorption, high hepatic first-pass metabolism and high P-gp efflux. The current research work, therefore, was undertaken to overcome the biopharmaceutical hiccups by developing the Mgf-phospholipid complex (PLCs) loaded in nanostructured lipidic carriers (NLCs). The PLCs and NLCs were prepared using refluxing, solvent evaporation and hot emulsification technique, respectively with various molar ratios of Mgf and Phospholipon 90 G, i.e., 1:1; 1:2; and 1:3. The complex was evaluated for various physicochemical parameters like drug content (96.57%), aqueous solubility (25-fold improved) and oil-water partition coefficient (10-fold enhanced). Diverse studies on the prepared complex using FTIR, DSC, PXRD and SEM studies ratified the formation of PLCs at 1:1 ratio. The PLCs were further incorporated onto NLCs, which were systematically optimized employing a face centered cubic design (FCCD), while evaluating for particle size, zeta potential, encapsulation efficiency and in vitro drug release as the CQAs. Caco-2 cell line indicated insignificant cytotoxicity, and P-gp efflux, bi-directional permeability model and in situ perfusion studies specified enhanced intestinal permeation parameters. In vivo pharmacokinetic studies revealed notable increase in the values of Cmax (4.7-fold) and AUC (2.1-fold), respectively, from PLCs-loaded NLCs vis-à-vis Mgf solution. In a nutshell, the promising results observed from the present research work signified boosted biopharmaceutical potential of the optimized PLCs-loaded NLCs for potentially augmenting the therapeutic efficacy of Mgf