Nanometers-thick self-organized Fe stripes: bridging the gap between surfaces and magnetic materials

We have fabricated 5nm-high Fe(110) stripes by self-organized (SO) growth on a slightly vicinal R(110)/Al2O3(11-20) surface, with R=Mo, W. Remanence, coercivity and domain patterns were observed at room temperature (RT). This contrasts with conventional SO epitaxial systems, that are superparamagnetic or even non-magnetic at RT due to their flatness. Our process should help to overcome superparamagnetism without compromise on the lateral size if SO systems are ever to be used in applications

A chemical, mechanical, and tribological analysis of DLC coatings deposited by magnetron sputtering

Diamond-like carbon is one of the most studied and used solid lubricants on the market. Despite this large use and its outstanding mechanical and tribological properties, there are still some unclear aspects related to its self-lubricant properties, and some drawbacks in the deposition methods. We deposited soft DLC films on Si(100), iron, and stainless steel substrates by PVD magnetron sputtering technique with a Cr/CrN adhesive interlayer. The DLC films were characterized from a chemical, mechanical, and tribological point of view. Our aim was to connect the coating chemical and mechanical characteristics to the different conditions used for the deposition, such as discharge power and substrate-target distance. We found a stronger sp(3) dependence on the discharge power for DLC deposited closer to the target. The tribological results did not depend on the chosen substrate-target distance, but rather on the hardness of the substrate. This could be ascribed to the better mechanical coupling of soft DLC films on harder substrates

Tuning the domain wall orientation in thin magnetic strips by induced anisotropy

We report on a method to tune the orientation of in-plane magnetic domains and domain walls in thin ferromagnetic strips by manipulating the magnetic anisotropy. Uniaxial in-plane anisotropy is induced in a controlled way by oblique evaporation of magnetic thin strips. A direct correlation between the magnetization direction and the domain wall orientation is found experimentally and confirmed by micromagnetic simulations. The domain walls in the strips are always oriented along the oblique evaporation-induced easy axis, in spite of the shape anisotropy. The controlled manipulation of domain wall orientations could open new possibilities for novel devices based on domain-wall propagation

EFFECT OF N2 PARTIAL PRESSURE ON THE GROWTH OF CHROMIUM NITRIDE COATINGS

Chromium nitride films has been prepared by reactive magnetron sputtering using a mixture of Ar and N2 gas. Keeping constant the total pressure during the film deposition the ratio of N2 to Ar has been varied from 0.3 to 5.0 to promote the growth of CrN films with different microstructure. The structural chemical characterization of grown films were performed by means of x-ray diffraction and scanning electron microscopy, auger electron spectroscopy and x-ray photoemission spectroscopy. Even if no clear correlation between material hardness and coating microstructure was observed with nanoindentation, the tribological characterization of the films, evidenced a strong dependence of the wear rate of the material by the process conditions. In particular we observed an improved wear resistance for coatings with a compressive residual stress

I lipidi nell'alimentazione dei pesci teleostei

I lipidi sono una categoria di composti fondamentali nell'alimentazione dei pesci teleostei. Vengono esaminate le principali caratteristiche chimico-fisiche degli acidi grassie la composizione acidica media dialcune fonti lipidiche impiegagate o impiegabili nella mangimistica per acquacoltura. Infine viene fatta una rassegna sugli effetti di fonti lipidiche non convenzionali sulle prestazioni produttive e le caratteristiche orgamolettiche di Salmonidi e di pesci di acqua calda

The effect of dietary coconut oil on reproductive traits and egg fatty acid composition in rainbow trout (Oncorhynchus mykiss)

Two hundred and twenty rainbow trouts (IBW: 700 g) were randomly allotted to four tanks, with a male/female ratio of 0.56. Fish were fed for 168 d with four experimental diets containing herring oil, cod liver oil and coconut oil with the following inclusion rates: diet A: 12-1-0% respectively; diet B: 6-1-6%; diet C: 0-1-12%; diet D: 0-0-13%. Irrespective of the dietary treatment, weight gains of broodstocks were high (> 3 g/d) and FCR below 2. No significant difference was observed concerning the total amount of eggs spawn, egg average weight (82.5 mg/egg) and lipid content (5.4 mg/egg). However, the fatty acid profile of eggs was significantly affected by the dietary treatments. The content of unsaturated fatty acids, particularly the n-3 fatty acid series (EPA and DHA) significantly decreased with increasing levels of coconut oil in the diet

. The effects of coconut oil on reproductive traits and fatty acid eggcomposition of rainbow Oncorhynchus mykiss, Walbaum)

Two hundred and twenty rainbow trouts (IBW: 700 g) were randomly allotted to four tanks, with a male/female ratio of 0.56. Fish were fed for 168 d with four experimental diets containing herring oil, cod liver oil and coconut oil with the following inclusion rates: diet A: 12-1-0% respectively; diet B: 6-1-6%; diet C: 0-1-12%; diet D: 0-0-13%. Irrespective of the dietary treatment, weight gains of broodstocks were high (> 3 g/d) and FCR below 2. No significant difference was observed concerning the total amount of eggs spawn, egg average weight (82.5 mg/egg) and lipid content (5.4 mg/egg). However, the fatty acid profile of eggs was significantly affected by the dietary treatments. The content of unsaturated fatty acids, particularly the n-3 fatty acid series (EPA and DHA) significantly decreased with increasing levels of coconut oil in the diet