Nanoliposomes for encapsulation and delivery of the potential antitumoral methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate

A potential antitumoral fluorescent indole derivative, methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate, was evaluated for the in vitro cell growth inhibition on three human tumor cell lines, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), and NCI-H460 (non-small cell lung cancer), after a continuous exposure of 48 h, exhibiting very low GI50 values for all the cell lines tested (0.25 to 0.33 μM). This compound was encapsulated in different nanosized liposome formulations, containing egg lecithin (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylglycerol (DPPG), DSPC, cholesterol, dihexadecyl phosphate, and DSPE-PEG. Dynamic light scattering measurements showed that nanoliposomes with the encapsulated compound are generally monodisperse and with hydrodynamic diameters lower than 120 nm, good stability and zeta potential values lower than -18 mV. Dialysis experiments allowed to monitor compound diffusion through the lipid membrane, from DPPC/DPPG donor liposomes to NBD-labelled lipid/DPPC/DPPG acceptor liposomes.     

Asymmetrically Recessed 50-nm Gate-Length Metamorphic High Electron-Mobility Transistor With Enhanced Gain Performance

We report the design, fabrication and characterization of ultrahigh gain metamorphic high electron-mobility transistors. In this letter, a high-yield 50-nm T-gate process was successfully developed and applied to epitaxial layers containing high indium mole fraction InGaAs channels grown on GaAs substrates. A unique gate recess process was adopted to significantly increase device gain by effectively suppressing output conductance and feedback capacitance. Coupled with extremely small 10 mum times 25 mum via holes on substrates thinned to 1 mil, we achieved a 13.5 dB maximum stable gain (MSG) at 110 GHz for a 30-mum gate-width device. To our knowledge, this is the highest gain performance reported for microwave high electron-mobility transistor devices of similar gate periphery at this frequency, and equivalent circuit modeling indicates that this device will operate at frequencies beyond 300 GHz.     

Novel peroxide‐vulcanized NBR‐PAni.DBSA blends,part 1: Preparation and characterization

Blends of poly(butadiene‐co‐acrylonitrile)‐polyaniline dodecylbenzenesulfonate [NBR‐PAni.DBSA] were successfully prepared using an internal mixer for the first time. Electrical conductivities of all the vulcanized blends (up to 10^?2 S/cm with a conductivity percolation threshold 6.0 wt %/5.4 vol % of PAni.DBSA) were not affected with the addition of dicumyl peroxide (DCP) as the vulcanizing agent. The FTIR spectra of vulcanized NBR‐PAni.DBSA blends resembled a superposition of the spectra of the raw materials, but with some notable peak shifts because of the changing intermolecular interactions between the polymers. Blends with ≤30 wt % of PAni.DBSA showed the best compatibility, i.e., with greatest peak shifts for their FTIR spectra and largest temperature shifts for their DSC recorded thermal events. The morphological studies (of both optical and transmission electron micrographs) showed that the thermomechanical mixing method had reduced the amounts of phase separation in all these NBR‐PAni.DBSA blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

CHF enhancement by honeycomb porous plate in saturated pool boiling of nanofluid

One strategy for severe accidents is in-vessel retention (IVR) of corium debris. In order to enhance the capability of IVR in the case of a severe accident involving a light-water reactor, methods to increase the critical heat flux (CHF) should be considered. Approaches for increasing the IVR capability must be simple and installable at low cost. Moreover, cooling techniques for IVR should be applicable to a large heated surface. Therefore, as a suitable cooling technology for required conditions, we proposed cooling approaches using a honeycomb porous plate for the CHF enhancement of a large heated surface in a saturated pool boiling of pure water. In this paper, CHF enhancement by the attachment of a honeycomb-structured porous plate to a heated surface in saturated pool boiling of a TiO₂-water nanofluid was investigated experimentally under atmospheric pressure. As a result, the CHF with a honeycomb porous plate increases as the nanoparticle concentration increases. The CHF is enhanced significantly up to 3.2 MW/m² at maximum upon the attachment of a honeycomb porous plate with 0.1 vol.% nanofluid. To the best of the author's knowledge, under atmospheric pressure, a CHF of 3.2 MW/m² is the highest value for a relatively large heated surface having a diameter exceeding 30 mm.     

Measurement of a Heated Surface Temperature Using a High-Speed Infrared Camera During Critical Heat Flux Enhancement by a Honeycomb Porous Plate in a Saturated Pool Boiling of a Nanofluid

Abstract

This article presents an experimental study to investigate the critical heat flux (CHF) enhancement mechanism using honeycomb porous plate (HPP). The CHF enhanced significantly with combination of the HPP and nanofluid, up to 3.2?MW/m² at maximum compared to a plain surface, 1.0?MW/m². The mechanism by which the CHF is improved in this system was elucidated by measuring the temperature of the heated surface using an indium tin oxide (ITO) heater and a high-speed infrared camera. The pool boiling experiment of water and nanofluid is performed under saturated temperature and atmospheric pressure conditions. The CHF values obtained using ITO heater is in good agreement with a conventional CHF pool boiling experiment with HPP attachment. High-speed infrared camera is analyzed to understand the behavior of local temperature at various locations over time. It is observed at the burnout condition, the highest average temperature is occurred at the intersection of HPP wall. Moreover, the reversible dry spots were initiated in the cell part of the HPP, and small dry spots coalesced into a growth of large irreversible dryout that leads to burnout. Further CHF enhancement could be realized if the initiation of the dryout region could be suppressed.