Energetic and economic evaluation of a poplar cultivation for the biomass production in Italy

The cultivation of crops for biomass production on good soils allows to reduce surplus production of food crops and increase the sustainability of energy production from the environmental point of view. The short rotation forestry (SRF), is only at a preliminary study level in Italy but, is already a reality in North Europe where was already developed an high planting density (6000–8000 cuttings ha^-1) technique and a whole mechanization of plantation and biomass harvest.On the basis of this cultivation technique, it was realized as an energetic and economic evaluation of a poplar SRF in Northern Italy. In detail, they were considered data of poplar growth in a plantation for the production of two-year whips in Western Po Valley considering SRF duration of 8 years and a biomass (20 t ha⁻¹ D.M.) harvest every 2 years. Indeed it was assumed to operate on a plantation in production (12.5% of the surface replanted every year) with a spacing 3.00 × 0.4 m (6700 cutting per hectare) that allows the use of conventional tractors.In this computing system it was pointed out a ratio between output and input energy of 13 and a cost of 80 € t⁻¹ of D.M. Nevertheless a positive energetic balance, the economic sustainability of poplar SRF depends, due to the present monopolistic energy management in the same countries, on political choices of chip price or public subventions to the producers.     

Gamma-ray emission gauge for solar salt level in a tank

One of the most investigated heat transfer fluid or heat storage medium in the field of thermal solar conversion is the “solar salt”, a mixture of nitrates NaNO₃/KNO₃, 60/40% by weight, respectively. The content of potassium in this fluid allows exploiting the self activity of the isotope ⁴⁰K to perform measurements useful for control or diagnostics of a solar plant. Here an experimental test on the non-invasive measurement of the salt level in a tank by means of gamma-ray spectrometry is shown.     

Synchrotron study on crystallization kinetics of milk fat under shear flow

A detailed synchrotron X-ray diffraction study on the kinetics of crystallization of anhydrous milk fat (AMF) and milk fat triacylglycerols (MFT) was done in a Couette cell at 17 °C, 17.5 °C and 20 °C under shear rates between 0 and 2880 s^?1. We observed shear-induced acceleration of the transition from phase α to β′ and the presence of crystalline orientation, but no effect of shear on the onset time of phase α was observed. A two stage regime was observed for the growth of phase β′. The first stage follows a series–parallel system of differential equations describing the conversion between liquid and crystalline phases. The second stage follows a diffusion-controlled regime. These mechanisms are consistent with the crystalline orientation, the growth of the crystalline domains and the observed displacement of the diffraction peak positions. The absence of the polar lipids explains the faster kinetics of MFT.     

Surface reactivity of MgO oxygen vacancies

The interaction of gas-phase molecules (O₂, CO and H₂) with oxygen vacancies (F_s centers) on the MgO(1 0 0) surface was studied by cluster models ab initio wave functions. The F_s centers exhibit a high reactivity towards O₂, CO and H₂ at variance with the regular sites of the MgO surface. The reaction proceeds through the formation of radical anions, O⁻₂ and CO⁻, via the transfer of one electron trapped in the surface cavity to the empty levels of the adsorbed molecule, and can lead to the heterolytic dissociation of the H₂ molecule.     

Surface modifications of molecularly imprinted polymers for improved template recognition in water media

New Restricted Access Materials—Molecularly Imprinted Polymers (RAM-MIP) were synthesized by using caffeine (CAFF), methacrylic acid (MAA), divinyl benzene (DVB) and glycidil methacrylate (GMA) as model template, functional monomer, crosslinking agent and pro-hydrophilic co-monomer, respectively. Furthermore, a screening of the ratio of functional monomer to template was performed. After the preliminary characterizations of conventional MIP prepared in absence of GMA, different GMA amounts were inserted in the pre-polymerization feeds and different reactions conditions were tested for GMA epoxide ring opening. In particular, perchloric acid, ammonia, lactic acid, glycine and triethylene glycol were chosen for this purpose. In perchloric acid and ammonia cases, a further modification was performed by phosphorylation and methylation procedures, respectively. Imprinting efficiency of all the obtained materials was evaluated by binding experiments using caffeine and its analogue theophylline both in organic and in water media. The increased hydrophilic characteristics of RAM polymers by water absorption measurement and protein binding experiments were performed.     

Syndiospecific oligomerization and polymerization of norbornene with titanium catalysts

Norbornene (NB) has been polymerized with TiCl₄-AlR₂Cl (R = Et, Me, iBu) at various NB/TiCl₄ molar ratio. The products obtained at low ratio (from ca. 5 to 12, depending on the mode of catalyst preparation) are a mixture of oligomers, from which it has been possible to isolate a crystalline heptamer having a 2,3-exo-disyndiotactic structure by single crystal X-ray analysis. The products obtained at higher NB/TiCl₄ ratio have a higher molecular weight (up to ca. 5000 for the soluble products) and consist of amorphous and crystalline polymers. The crystalline polymers, characterized by X-ray and ¹³C NMR, are a new type of stereoregular polynorbornene (PNB), having a 2,3-exo-disyndiotactic structure. Mechanistic aspects are examined and a precise assignment of some resonances in the ¹³C NMR spectrum of vinyl-type PNBs is reported.     

Polyphenol Conjugates and Human Health: A Perspective Review

In recent years, antioxidants have gained great importance because of their potential use in food, pharmaceutical, and cosmetic industries. This interest is rooted in the cumulative evidence connecting active oxygen and free radicals with numerous human degenerative disorders, such as cardiovascular diseases, cancer, aging, and atherosclerosis. Polyphenols are the major class of antioxidant able to reduce the oxidative damages of lipids, proteins, enzymes, carbohydrates, and DNA in living cells and tissues. Among the realm of polyphenol compounds, polyphenol conjugates have been proposed as innovative materials which, by combining the advantageous properties of both the components, can increase the efficiency of antioxidants and their range of application in nutritional and biomedical fields. This work is an overview of the different class of polyphenol conjugates, which will be analyzed in terms of nutritional and biological properties, showing how these bio-conjugates will positively affect the human health.     

Expression of different types of [FeFe]-hydrogenase genes in bacteria isolated from a population of a bio-hydrogen pilot-scale plant

[FeFe]-hydrogenases are the enzymes responsible for high yield H₂ production during dark fermentation in bio-hydrogen production plants. The culturable bacterial population present in a pilot-scale plant efficiently producing H₂ from waste materials was isolated, classified and identified by means of 16S rDNA gene analysis. The culturable part of the mixed population consists of nine bacterial species that include non-hydrogen producers (Lactobacillus, Enterococcus and Staphylococcus) and several Clostridium that are directly responsible for H₂ production.     

Fracture mechanics for the reconstruction of Noto Cathedral

The baroque buildings of Sicily should be ideal subjects of Fracture Mechanics, having heights up to 60 m, PGA up to 0.30×g, low strengths, few reinforcements, aggregate with irregular stones in the most vulnerable zones. Their analysis constitutes a severe test. The damages between the earthquake on 13.12.1990 and its collapse on 13.03.1996 are due to cracking development always. A monotonic static analysis by FE is performed here. Prestressing and lightening are examined.