Chameleon Coatings: Adaptive Surfaces to Reduce Friction and Wear in Extreme Environments

Adaptive nanocomposite coating materials that automatically and reversibly adjust their surface composition and morphology via multiple mechanisms are a promising development for the reduction of friction and wear over broad ranges of ambient conditions encountered in aerospace applications, such as cycling of temperature and atmospheric composition. Materials selection for these composites is based on extensive study of interactions occurring between solid lubricants and their surroundings, especially with novel in situ surface characterization techniques used to identify adaptive behavior on size scales ranging from 10−10 to 10−4 m. Recent insights on operative solid-lubricant mechanisms and their dependency upon the ambient environment are reviewed as a basis for a discussion of the state of the art in solid-lubricant materials

Current and emerging therapeutic options for the treatment of chronic chagasic cardiomyopathy

Chagas’ disease is an endemic disease in Latin America caused by a unicellular parasite (Trypanosoma cruzi) that affects almost 18 million people. This condition involves the heart, causing heart failure, arrhythmias, heart block, thromboembolism, stroke, and sudden death. In this article, we review the current and emerging treatment of Chagas’ cardiomyopathy focusing mostly on management of heart failure and arrhythmias. Heart failure therapeutical options including drugs, stem cells and heart transplantation are revised. Antiarrhythmic drugs, catheter ablation, and intracardiac devices are discussed as well. Finally, the evidence for a potential role of specific antiparasitic treatment for the prevention of cardiovascular disease is reviewed

Enantioselective Total Synthesis of (-)-Nardoaristolone B via a Gold(I)-Catalyzed Oxidative Cyclization

The first enantioselective total synthesis of (−)-nardoaristolone B is accomplished by the implementation of an enantio- and diastereoselective copper(I)-catalyzed conjugate addition/enolate trapping sequence and a gold(I)-catalyzed oxidative cyclization (intermolecular oxidant), employed for the first time in total synthesis

BIM-based structural survey design

Abstract The study, which is part of the digitalization project of the public real estate portfolio of the City of Turin (TOBIM), explores the use of parametric structural models in organizing the knowledge and the data involved in the investigations and analysis on an existing building. The recommended approach exploits Building Information Modelling to set up a graphic and alphanumeric database of interoperable information that can be implemented throughout the building life cycle. Specifically, this paper promotes solutions focused on maximizing BIM data for structural survey design activities. The case study analyzed is a pavilion school complex of the 70s located in Turin

Quality maintenance performance and resistance to Tribolium castaneum and Plodia interpunctella penetration of an alternative packaging material for semolina

Insect attacks to food packages are a major concern for food producers, who are often blamed for being responsible for the occurrence of contamination which seriously affects the image of the company. Wheat semolina is commonly packed in paper bags, which do not always offer sufficient protection against insect pests. The present research evaluated the performance of a new packaging alternative, consisting of paper laminated with polypropylene (P+CPP), in terms of resistance to penetration by two common cereal product pests, namely Tribolium castaneum and Plodia interpunctella, and quality maintenance of the packaged product. Neither of the two pest species tested were able to pierce the P+CPP, while no differences were observed in the time required to penetrate other materials. Moreover, quality parameters, namely pH, acidity and color, did not differ significantly among samples packed in different materials. The new P+CPP combination is a promising alternative for the packaging of semolina, because it offers improved protection against pests compared with conventional materials, while maintaining the paper appearance of traditional packaging

Models of Passive and Reactive Tracer Motion: an Application of Ito Calculus

By means of Ito calculus it is possible to find, in a straight-forward way, the analytical solution to some equations related to the passive tracer transport problem in a velocity field that obeys the multidimensional Burgers equation and to a simple model of reactive tracer motion.Comment: revised version 7 pages, Latex, to appear as a letter to J. of Physics

Nitrogen and Hydrogen Plasma Treatments of Multiwalled Carbon Nanotubes

This article investigates plasma treatment of vertically aligned multiwall carbon nanotube (CNT) films in different plasma environments for modification of surface chemistry and morphology. The surfaces of the CNTs were functionalized with a pulsed dc plasma treatment, where the power was directly applied to the nanotube film in low pressure argon/nitrogen and argon/hydrogen backgrounds. Optical emission spectroscopy was used to detect atomic and molecular excitations in the gas mixtures as well as in pure gases in the vicinity of the CNT films. In situx-ray photoelectron spectroscopy was performed on the treated samples to examine CNT surface chemistry after treatment. The analysis of CNT films after nitrogen and hydrogen treatment indicated formation of both C-N and C-H bonds, respectively. Correlations of the plasma characteristics to the surface chemistry and morphology of the CNT surfaces are discussed

e

The disc formation mechanism of B[e] supergiants is one of the puzzling phenomena in massive star evolution. Rapid stellar rotation seems to play an important role for the non-spherically symmetric mass-loss leading to a high-density disc- or ring-like structure of neutral material around these massive and luminous objects. The radial density and temperature structure as well as the kinematics within this high-density material are, however, not well studied. Based on the high-resolution optical spectra of a sample of B[e] supergiants in the Magellanic Clouds we especially searched for tracers of the kinematics within their discs. Besides the well-known [Oi] lines, we discovered the [Caii] λλ7291, 7324 lines which can be used as a complementary set of disc tracers. We find that these lines originate from very high density regions, located closer to the star than the [Oi] λ5577 line-forming region. The line profiles of both the [Oi] and the [Caii] lines indicate that the discs or rings of high-density material are in Keplerian rotation. We estimate plausible ranges of disc inclination angles for the sample of B[e] supergiants and suggest that the star LHA120-S22 might have a spiral arm rather than a disc.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

HYDROCARBONS REMOVAL FROM BILGE WATER BY ADSORPTION ONTO ACTIVATED BIOCHAR FROM POSIDONIA OCEANICA

The normal operations carried out on the boats during navigation generate waste waters such as oily bilge water. The latter is the aqueous mixture of potential pollutants of different origins and types: oily fluids, lubricants and greases, cleaning fluids and other wastes that accumulate in the lower part of the vessel [1,2]. The current legislation provides that they can be discharge directly into the sea if the concentrations of some components are below the expected limits. In particular, with regard to oil / hydrocarbons contamination, the current regulatory limit is 15 mg L-1 of total hydrocarbons. The present work starts from a public/private partnership funded by a grant of the Ministry of Economic Development (MiSE). Among the aims of the project, novel methods shall be tested for the reduction of hydrocarbons concentration at values below 5 mg L-1. Moreover, instrumental techniques able to quickly measure the required low hydrocarbons concentration were tested. Among the different steps of bilge water treatment in pilot plant (coagulation, flotation, centrifugation, adsorption etc.), the latter requires the use of adsorbent materials able to reduce the oily concentration below the legal limits. Here we have hosen, optimized and tested materials obtained from bio-oil production waste, a biochar obtained by pyrolysis of Posidonia oceanica, a marine plant widespread in the Mediterranean sea. means of acid or alkali treatments. Moreover, a commercial activated carbon (Filtrasorb 400) has been used for comparison purpose. Synthetic bilge waters were prepared following the reference standards [3] for the preparation of test fluids (used to test the bilge separator plant), containing DMA (distillate marine fuel) and SLS (sodium lauryl sulfate). Batch adsorption isotherms were carried out without ionic medium and at different ionic strengths in NaCl in order to evaluate the effect of salinity on the adsorption ability of dsorbent materials. The same adsorbents were tested by column experiments. In particular, a bench pilot system was built (Figure 1.) and breakthrough curves were obtained changing amount of adsorbent material in column, flow rate, initial DMA and surfactant concentrations. Several instrumental techniques (turbidimetry, TOC, HPLC-QQQ and HPLC-FLD) have been used to measure surfactant and hydrocarbon concentrations in experimental samples. The batch experimental data were fitted with the most used isotherm models (Langmuir, Freundlich, Sips) and important considerations were made on the breakthrough curves of column experiments