Search results for "Storage"
showing 10 items of 1239 documents
Photoreactions in Langmuir-Blodgett-Kuhn multilayer assemblies of liquid crystalline azo-dy side-chain polymers
2007
Reversible and persistent optical data storage in Langmuir-Blodgett-Kuhn liquid crystalline systems has been reported recently. Depending on the molecular structure, the trans-cis isomerization in these systems (induced by illumination with UV- and VIS-light) leads to different macroscopic behavior of the chromophore percentage on the photo-induced structural changes in a series of statistical copolymers.
Antibacterial performance of solvent cast polycaprolactone (PCL) films containing essential oils
2013
Abstract The increase of consumer demand for higher quality and longer shelf-life in foods, while reducing the use of non-compostable packaging materials, has encouraged research on biopolymers incorporating natural antimicrobial compounds. Cinnamaldehyde (CNMA) and allyl isothiocyanate (AITC) were incorporated into polycaprolactone (PCL) films by solvent casting. The release study was carried out by means of ATR and transmission FTIR spectroscopy and showed high volatility of the essential oils during the film forming process. While only negligible quantities of AITC were retained in the polymer matrix after film curing, the release of CNMA was prolonged for at least 50 h at room temperatu…
Thermal, glass-forming, nonlinear optical and holographic properties of "push-pull" type azochromophores with triphenyl moieties containing isophoren…
2013
Molecular organic compounds with electron donating fragment bounded through π-conjugated system with electron acceptor fragment, as well as with incorporated triphenyl groups in their molecules show potential for creating cheap and simple solution processable materials with nonlinear optical properties. Additional insertion of azobenzene fragment in their structures makes them also possible to form holographic volume and surface relief gratings (SRG) after exposure to laser radiation, which could be useful for holographic data storage. For these purposes polymers are generally used. However, their application is complicated and challenging task as in every attempt to obtain the same polymer…
Activities of some peptidases and proteinases in germinating kidney bean, Phaseolus vulgaris
1986
The activities of aminopeptidase (EC 3.4.11), dipeptidase (EC 3.4.13), carboxypeptidase (EC 3.4.16), naphthylamidase (EC 3.4.11) and proteinases (EC 3.4.21) were assayed in extracts from the cotyledons and the axial tissues of resting and germinating kidney beans (Phaseolus vulgaris L. cv. Processor). The activities of the alkaline peptidases (aminopeptidase hydrolyzing Leu-Tyr at pH 9.2 and dipeptidase acting on Ala-Gly at pH 8.5) and naphthylamidases (hydrolyzing Leu-β-naphthylamide at pH 6.4) were high in the cotyledons of resting seeds, but decreased during germination. This decrease was faster than the loss of the total nitrogen. On the contrary, the activities of carboxypeptidase (hyd…
Polymer Selection and Cell Design for Electric-Vehicle Supercapacitors
2000
Supercapacitors are devices for applications requiring high operating power levels, such as secondary power sources in electric vehicles (EVs) to provide peak power for acceleration and hill climbing. While electronically conducting polymers yield different redox supercapacitor configurations, devices with the n-doped polymer as the negative electrode and the p-doped polymer as the positive one are the most promising for EV applications. Indeed, this type of supercapacitor has a high operating potential, is able to deliver all the doping charge and, when charged, has both electrodes in the conducting (p- and n-doped) states. This study reports selection criteria for polymer materials and ce…
Hydrothermal liquefaction of waste biomass in stirred reactors: One step forward to the integral valorization of municipal sludge
2020
Abstract Hydrothermal liquefaction (HTL) of municipal sludge (MS) was performed at 350 °C for 30 min (subcritical water) and at 400 °C for 0 min (supercritical water) at fixed kinetic severity (LogR0 = 8.9) in static and stirred batch reactors to study the effect of the flow regime on the energy recovery (ER) of the process and on the quality of the products. With adopted experimental procedures it was possible to reduce to less than 10% the yield of lost organic compounds, termed volatiles (VT), and to collect and quantify a liquid hydrocarbon fraction (HC) separated from the biocrude (BC). The highest value of the HC yield, 25% w/w, was obtained in supercritical conditions. The C content …
Stability of fatty acids and tocopherols during cold storage of human milk
2012
The stability of fatty acids and tocopherols from human milk from 8 healthy lactating mothers was determined in fresh milk and after cold storage. Refrigeration at 4 °C for 48 h or freezing at −20 °C for 30 days did not significantly decrease fatty acid contents (mg per 100 g human milk), or concentrations of α-, β-, γ- and δ-tocopherol isomers, compared with fresh milk. Results obtained in the present study showed that cold storage under the usual storage conditions in neonatal units, at home or in milk banks did not have a detrimental effect upon fatty acids and tocopherols contents in human milk. Thus, infants can receive stored human milk without losses in the nutritional value of these…
Progress in polymeric material for hydrogen storage application in middle conditions
2014
Hydrogen sorption using a manganese oxide anchored to PEEK (Poly(ether-ether-keton)) matrix was studied. The functionalization process and the obtained results on hydrogen storage capability of the synthesized polymer are reported. The functionalised polymer was characterised by Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction and Volumetric Hydrogen sorption measurements. Different synthesis conditions in terms of precursor concentration and reaction time were used and the direct correlation between manganese oxide percentage and hydrogen storage capability was confirmed. In this way different powders were synthesised. It is assumed that the sample with 78 …
Oxygen-induced changes in hemoglobin expression in Drosophila
2008
The hemoglobin gene 1 (dmeglob1) of the fruit fly Drosophila melanogaster is expressed in the tracheal system and fat body, and has been implicated in hypoxia resistance. Here we investigate the expression levels of dmeglob1 and lactate dehydrogenase (a positive control) in embryos, third instar larvae and adult flies under various regimes of hypoxia and hyperoxia. As expected, mRNA levels of lactate dehydrogenase increased under hypoxia. We show that expression levels of dmeglob1 are decreased under both short- and long-term hypoxia, compared with the normoxic (21% O2) control. By contrast, a hypoxia/reoxygenation regime applied to third instar larvae elevated the level of dmeglob1 mRNA. A…
Diffusional enhancement of holograms: phenanthrenequinone in polycarbonate
2002
As a further development of the manufacture of holographic gratings by the diffusion of phenanthrenequinone in polymer glass, the traditionally employed poly(methyl methacrylate) is replaced by poly(bisphenol-A-carbonate). The post-exposure growth and decay of the gratings in the two materials are compared at different spatial periods and temperatures. The medium with polycarbonate demonstrates a fortunate combination of significantly improved stability of the gratings and their faster development. Our results indicate that the polycarbonate materials promise to be suitable media for holographic optical elements and data storage.