Unipolar plasma electrolytic oxidation: Waveform optimisation for corrosion resistance of commercially pure titanium

This study deals with the anodisation of titanium grade 2 in 0.5-M sulphuric acid using a pulsed signal in a unipolar regime. The electrical parameters investigated are voltage, frequency and duty cycle. The use of duty cycles with a high percentage of anodic polarisation (90%), combined with high frequencies (1000 Hz) and the higher voltage tested (220 V), favoured the establishment of a plasma regime involving strong dielectric discharges, allowing the growth of thicker oxides but with rough architecture. The corrosion resistance of the formed film has been characterised by potentiodynamic tests in 0.5-M NaBr for localised corrosion resistance and by immersion tests in 10% v/v sulphuric acid solution for a uniform corrosion assessment. Current–time curves, visual observations and electron microscope analysis (scanning electron microscopy, energy-dispersive X-ray spectroscopy) were the tools selected to provide a correlation between technological parameters and oxide growth mechanism. For localised and uniform corrosion, anodisation at 220 V with a high level of anodic polarisation (90%) and frequency (1000 Hz) was verified to be particularly advantageous.     

Proton nuclear magnetic resonance rapid and structure-specific determination ofω-3 polyunsaturated fatty acids in fish lipids

Based on proton nuclear magnetic resonance (¹H-NMR) spectroscopy, a rapid and structure-specific method for the determination of ω-3 polyunsaturated fatty acids (PUFAs) in fish lipids is presented. The different chemical shift observed for the methyl resonance of ω-3 PUFAs (δ=0.95 ppm) with respect to the methyl resonance of all other fatty acids (δ=0.86 ppm) has provided the possibility of proposing a new and rapid method for the determination of ω-3 PUFA content. Twenty-four fish lipid samples (raw, cooked and canned albacore tuna) produced results that showed good agreement between¹H-NMR analysis and gas chromatographic determination. Raw and cooked samples showed significantly higher levels of ω-3 PUFA than canned tuna.     

Vocal production in postpartum dairy cows: Temporal organization and association with maternal and stress behaviors

Mammalian vocalizations can encode contextual information in both the spectrographic components of their individual vocal units and in their temporal organization. Here we observed 23 Holstein-Friesian dairy cows immediately after birth during interactions with their calf and when their calf was separated to the other side of a fence line. We investigated whether the vocalizations emitted in these postpartum contexts would vary temporally. We also described the maternal and stress behaviors preceding and following postpartum vocal production using kinematic diagrams and characterized call sequence structure. The kinematic diagrams highlight the disruption of maternal responses caused by calf separation and show that behavioral and vocal patterns varied according to the cows' emotional states and proximity to the calf in both contexts. During calf interactions, cows mainly produced closed-mouth calls simultaneous to licking their calf, whereas an escalation of stress responses was observed during calf separation, with the cows approaching the fence line, becoming alert to the calf, and emitting more mixed and open-mouth calls. Call sequences were similarly structured across contexts, mostly containing repetitions of a single call type, with a mean interval of 0.57 s between calls and a greater cumulative vocalization duration, attributed to an increased number of vocal units per sequence. Overall, calf separation was associated with a greater proportion of calls emitted as a sequence (inverse of single isolated calls), a shorter interval between separate call sequences, and a greater number of vocal units per sequence, compared with calf interactions. These temporal vocal features varied predictably with the high stress expression from cows during calf separation and may represent temporal modulations of emotional expression. Despite the noisy farm soundscape, empirical call type and temporal vocal features were easy to measure; thus, findings could be applied to future cattle studies wishing to analyze vocalizations for on-farm welfare assessments.     

On the Cooling Rate-Microstructure Relationship in Molten Metal Gas Atomization

Metallurgical and Materials Transactions A - Gas atomization is the most used powder production technique since it provides good control on particles shape, surface oxidation and dimension. It is a...     

Seismic noise in Lipari and Vulcano Islands,Southern Thyrrenian Sea,Italy

The results of a study of frequency and amplitude distribution of ground noise at Lipari and Vulcano (Aeolian Island) are here reported.Low frequency noise distribution suggests the presence of a geothermal system while high frequency seems to be linked to fumaroles and hot springs activity.     

A Comparative Study of the In Vitro and In Vivo Release of Dexamethasone from a Spray-On Bandage and Timed Release Aerosol

The formulation of several dexamethasone topical delayed release aerosol preparations was studied. Ethylcellulose and tributyl citrate were the film-forming agent and plasticizer, respectively, for the spray-on bandage formulation. The aerosol timed release preparation contained dexamethasone microcapsules suspended in a fluorocarbon aerosol propellant by isopropyl myristate and fumed silica. Both preparations were evaluated using an in vitro method which measured the release of dexamethasone hourly for eight hours. In vitro studies showed that each of the formulations delayed the release of dexamethasone. In the in vivo tests aerosols were sprayed on the unabraded back area of rabbits and the increased 17 - hydroxycorticosteriod urine levels at 24, 48, and 72 hours indicated dexamethasone absorption. In vivo studies indicated that absorption did not occur with the timed release preparation containing dexamethasone microcapsules. However, dexamethasone from the spray-on bandage preparation was absorbed over 72 hours. A commercially marketed topical dexamethasone cream was used for comparison in evaluating the two experimental formulations; however, in vivo studies showed that no absorption occurred with this preparation.

In recent years, a great deal of work has been directed towards the application of medicated polymeric films or tissue adhesives onto the skin to treat minor dermatological problems or serious skin wounds. Among the factors to be considered are: incorporation of a specific active ingredient, the mode of application and the dosage form. Lange and Fang (1,2) developed spray-on bandages using water soluble resins and water as the solvent. Fischl (3) evaluated the effectiveness of a cyanoacrylate monomer in closing skin incisions without affecting wound healing. Bhaskar and Cutright (4) showed that butyl cyanoacrylate could be successfully used as a surface dressing while reducing the degree of inflammation. Sciarra and Gidwani (5,6) reported on the release of gentian violet from selected polymer and plasticizer combinations and established various polymer-plasticizer combinations which could be applied as an aerosol spray. Other studies (7,8) have shown that ethylcellulose and a thermoplastic polyamide resin have potential use in spray-on bandage formulations.

The results indicated that the anti-infectives were released from the films and the spray-on bandages reduced the degree of infection about the wound.

The process of microencapsulation has been applied to various industrial and medical uses. Microcapsules can be prepared so that the encapsulated material will be released slowly. There are various methods of microencapsulation including coacervation, phase separation, interfacial polymerization, an electrostatic method, and vacuum metalization and they have been successfully used with selected drugs (9-13).

The purpose of this study was to develop and evaluate different aerosol formulations containing a therapeutic agent which can be slowly released. In vitro and in Vivo systems were used to evaluate the release and absorption of the drug in the test animals.     

First data from the EGLE experiment onboard the ISS

EGLE is a wide frequency band search- coil magnetometer designed and built at the Roma Tre University. It has been installed onboard the ISS by the Italian astronaut Roberto Vittori on April 25, 2005 within the LAZIO- EGLE experiment carried out during the ENEIDE Soyuz mission. The scope of the experiment is to test EGLE in space and to investigate geomagnetic field variations. The main applications of EGLE are the study of electromagnetic environment inside the ISS, the correlation of magnetic field data with particle fluxes detected by LAZIO particle detector, and the monitoring of ionospheric perturbations possibly caused by Earth seismic activity. Since continuous electromagnetic field measurements on board the ISS are important for diverse space applications, a magnetometer with a suitable design is requested. Appropriate solutions for these applications, which have been adopted by EGLE, are in particular the use of 1- Wire technology and the possibility to detect by means of a search- coil magnetometer a large portion of the ULF frequency band, usually measured by flux- gate probes. To investigate the topside ionosphere electromagnetic environment and stability of Van Allen radiation belts in relation with seismic and anthropogenic electromagnetic emissions, a specific satellite mission (the ESPERIA project) has been designed for the Italian Space Agency (ASI), and up to now a few instruments of its payload have been built and tested in space. One of them is exactly the EGLE search- coil magnetometer. The first magnetic observations performed by this instrument reveal to be promising and demand for a further and deeper analysis based on a longer time series of data.     

The importance of landscape in wine quality perception: An integrated approach using choice-based conjoint analysis and combination-based permutation tests

This work’s aim is to evaluate the importance of landscape in wine quality perception using a novel integrated approach based on two statistical techniques, i.e. choice-based conjoint analysis (Gustafsson et al., 2001) and combination-based permutation tests (Corain and Salmaso, 2004, Pesarin and Salmaso, 2009a). To this end we developed a preference choice experiment which was submitted to a sample of respondents during blind wine tasting meetings. The obtained results allow us to weigh up and emphasise the importance of an attractive landscape to the perception of a finer quality of wine. Indeed, we noticed that associating wine to an image of greater visual impact, i.e. an evocative landscape, induces a significantly higher preference for the tasted wine. Moreover, the integrated application of choice-based conjoint analysis and combination-based permutation tests allows us to identify the specific relationship each market segment has with landscape, price and wine quality.     

The synthesis and structural study of two benzothiazolyl azo dyes: X-ray crystallographic and computational study of azo–hydrazone tautomerism

The synthesis, FT-IR, ¹H and ¹³C NMR characterisation, as well as crystal and molecular structure determined by single-crystal X-ray diffraction data, of two azo dyes derived from 6-aminobenzothiazole: 6-[(4-N,N-dimethylaminophenyl)diazenyl]benzothiazole and 6-[(2-hydroxy-1-naphthyl)diazenyl]benzothiazole are reported. Both dyes are essentially planar with the exclusion of methyl groups in 6-[(4-N,N-dimethylaminophenyl)diazenyl]benzothiazole, which exibits 100% E-configuration in terms of orientation of the substituents about the central azo linkage. Single-crystal X-ray study of 6-[(2-hydroxy-1-naphthyl)diazenyl]benzothiazole was undertaken to established whether the hydrazone or azo tautomer was present in the solid state as well as any potential shift in tautomeric equilibrium imparted by temperature variation (296 and 100 K). Density functional theory calculations revealed that the hydrazone tautomer was more stable than the azo tautomer and that the tautomeric equilibrium was shifted towards the hydrazone form at lower temperature.     

Carbon nanotube ropes proposed as particle pipes

Classical molecular dynamics studies of carbon ion-irradiation on ropes made of (10, 10) carbon nanotubes have been made. The carbon ions were fired into the rope on the outside of the nanotubes in a direction almost parallel to the longitudinal axis. Channeling takes place when the incidence angle is smaller than a critical angle. The dependence of the critical angle on the energy follows an inverse square root function. Our calculations show that the dependence of the critical angle on the energy is very similar for intra- and inter-tube channeling. Wave creation during the collision process is discussed.