Search results for " solution"
showing 10 items of 3084 documents
Lignin-based activated carbon-supported metal oxide catalysts in lactic acid production from glucose
2021
In this study, heterogeneous biomass-based activated carbon-supported metal oxide catalysts were prepared and tested for lactic acid production from glucose in aqueous solution. Activated carbons were produced from hydrolysis lignin by chemical (ZnCl2) or steam activation and modified with a nitric acid treatment and Sn, Al, and Cr chlorides to obtain carbon-based metal oxide catalysts. The modification of the carbon support by nitric acid treatment together with Sn and Al oxides led to an increase in lactic acid yield. The highest lactic acid yield (42%) was obtained after 20 minutes at 180 °C with the Sn/Al (5/2.5 wt.%) catalyst on steam-activated carbon treated by nitric acid. Reusabilit…
The CdCl2 effects on synthetic DNAs encaged in the nanodomains of a cationic water-in-oil microemulsion
2011
The present work is dedicated to the study of the interactions of CdCl(2) with the synthetic polynucleotides polyAT and polyGC confined in the nanoscopic aqueous compartment of the water-in-oil microemulsion CTAB/pentanol/hexane/water, with the goal to mimic in vitro the situation met by the nucleic acids in vivo. In biological structures, in fact, very long strings of nucleic acids are segregated into very small compartments having a radius exceedingly smaller than the length of the encapsulated macromolecule. For comparison, the behaviour of polyGC was also studied in aqueous solutions of matched composition. The conformational and thermal stabilities of both polynucleotides enclosed in t…
ICT-Related Intangibles and Organizational Innovation: Indicators for Improving Connectedness and Flexibility
2012
In this paper we address the role of ICT-related intangible assets in organizational innovation. We focus on two important innovation enablers: first, connectedness, the ability of individuals to create and maintain connections to each other; and second, organizational flexibility to adapt to changing needs. For connectedness and flexibility, an agile ICT infrastructure and information management services are needed. Through a Delphi study, we identified several factors hindering organizational innovation, and formulated a set of indicators and related metrics for improvement. We conclude that it is necessary to consider ICT-related factors when organizations pursue improving their innovati…
Boundary value problem with integral condition for a Blasius type equation
2016
The steady motion in the boundary layer along a thin flat plate, which is immersed at zero incidence in a uniform stream with constant velocity, can be described in terms of the solution of the differential equation x'''= -xx'', which satisfies the boundary conditions x(0) = x'(0) = 0, x'(∞) = 1. The author investigates the generalized boundary value problem consisting of the nonlinear third-order differential equation x''' = -trx|x|q-1x'' subject to the integral boundary conditions x(0) = x'(0) = 0, x'(∞) = λ∫0ξx(s) ds, where 0 0 is a parameter. Results on the existence and uniqueness of solutions to boundary value problem are established. An illustrative example is provided.
Preparation of Polymeric Nanoparticles by Photo-Crosslinking of an Acryloylated Polyaspartamide in w/o Microemulsion
2004
Biodegradable polymeric nanoparticles have been prepared by UV irradiation of an acryloylated water soluble polymer by an inverse microemulsion. The starting polymer was a α,β‐poly(N‐2‐hydroxyethyl)‐D,L‐aspartamide (PHEA) partially functionalized with glycidyl methacrylate (GMA) in order to introduce reactive vinyl groups in the side chain. The PHEA‐GMA copolymer obtained (PHG) was crosslinked by UV irradiation of the inverse microemulsion prepared by mixing an aqueous solution of PHG with propylene carbonate (PC)/ethyl acetate (EtOAc) in the presence of sorbitan trioleate (SPAN 85) as surfactant. Nanoparticles obtained were characterized by FTIR spectrophotometry, transmission electron mic…
From isolated 1H-pyrazole cryptand anion receptors to hybrid inorganic-organic 1D helical polymeric anion receptors
2015
We report a novel 1-D helical coordination polymer formed by protonated polyamine 1H-pyrazole cryptands interconnected by Cu2+ metal ions that are able to encapsulate anionic species behaving as a multianion receptor. Switching from a monomeric receptor to a polymeric receptor is activated by metal ions and pH.
Rapid self-healing and anion selectivity in metallosupramolecular gels assisted by fluorine-fluorine interactions.
2017
Simple ML2 [M = Fe(II), Co(II), Ni(II)] complexes obtained from a perfluoroalkylamide derivative of 4-aminophenyl-2,2′,6,2′-terpyridine spontaneously, yet anion selectively, self-assemble into gels, which manifest an unprecedented rapid gel strength recovery, viz. self-healing, and thermal rearrangement in aqueous dimethyl sulfoxide. The key factor for gelation and rheological properties emerges from the fluorine–fluorine interactions between the perfluorinated chains, as the corresponding hydrocarbon derivative did not form metallogels. The perfluoro-terpyridine ligand alone formed single crystals, while its Fe(II), Co(II) or Ni(II) complexes underwent rapid gelation leading to highly enta…
Halloysite Nanotubes Coated by Chitosan for the Controlled Release of Khellin
2020
In this work, we have developed a novel strategy to prepare hybrid nanostructures with controlled release properties towards khellin by exploiting the electrostatic interactions between chitosan and halloysite nanotubes (HNT). Firstly, khellin was loaded into the HNT lumen by the vacuum-assisted procedure. The drug confinement within the halloysite cavity has been proved by water contact angle experiments on the HNT/khellin tablets. Therefore, the loaded nanotubes were coated with chitosan as a consequence of the attractions between the cationic biopolymer and the halloysite outer surface, which is negatively charged in a wide pH range. The effect of the ionic strength of the aqueous medium…
Requirements for using simulation to design and assess wireless ATM handover solutions
1999
Wireless ATM (WATM) has been widely considered as a solution for broadband wireless services. Handover is one of the most important mobility support functions in the WATM network. Many handover solutions have been proposed, analysed, and benchmarked. Simulations have been broadly used to assess these solutions. However, there are many dilemmas in how simulation has been applied as a research methodology: heterogeneous simulation systems used, lack of comparison with other related work, biased conclusions, and unavailability of simulation models and systems to researchers. The WATM research community lacks a standard and commonly acceptable methodology for applying simulation. To address thi…
Plasmonic Stripes in Aqueous Environment Co-Integrated With Si3N4 Photonics
2018
We demonstrate the design, fabrication, and the experimental characterization of gold-based plasmonic stripes butt-coupled with low-pressure-chemical-vapor-deposition (LPCVD)-based Si3N4 waveguides for the excitation of surface-plasmon-polariton (SPP) modes in aqueous environment. Plasmonic gold stripes, in aqueous environment, with cross-sectional dimensions of 100 nm × 7 μm were interfaced with 360 nm × 800 nm Si3N4 waveguides cladded with low-temperature-oxide, exploiting linear photonic tapers with appropriate vertical (VO) and longitudinal (LO) offsets between the plasmonic and photonic waveguide facets. An interface insertion loss of 2.3 ± 0.3 dB and a plas…