Transmission of Impacts during Mechanical Grape Harvesting and Transportation

The aim of the research was to study vibrational stress on grapes during mechanical harvesting, transfer and delivery to the winery, in order to identify the most critical stages and the consequent effects on the winemaking. An instrumented sphere was used to evaluate and memorise the impacts in the grape harvester and means of transport. Three treatments, obtained by differing harvesting method (manual and mechanical) and transport type (short and long distance), were compared. A correlation was sought between the transmitted stresses and characteristics of the harvested product. The effects on product quality were evaluated by chemical analyses of the musts and sensorial analysis of the end-product, vinified using the same procedure

La Fisica nel parco giochi fa bene anche al curriculum

Viene descritto un percorso didattico di fisica attraverso le attrazioni del parco di divertimenti di Mirabilandia (Ravenna). Viene in particolare illustrata un’esperienza di integrazione del percorso nel curriculum scolastico di fisica, condotta in una classe III di liceo scientifico, che ha avuto risultati positivi sull’apprendimento

Kelvin-Helmholtz instability at proton scales with an exact kinetic equilibrium

The Kelvin-Helmholtz instability is a ubiquitous physical process in ordinary fluids and plasmas, frequently observed also in space environments. In this paper, kinetic effects at proton scales in the nonlinear and turbulent stage of the Kelvin-Helmholtz instability have been studied in magnetized collisionless plasmas by means of Hybrid Vlasov-Maxwell simulations. The main goal of this work is to point out the back reaction on particles triggered by the evolution of such instability, as energy reaches kinetic scales along the turbulent cascade. Interestingly, turbulence is inhibited when Kelvin-Helmholtz instability develops over an initial state which is not an exact equilibrium state. On the other hand, when an initial equilibrium condition is considered, energy can be efficiently transferred towards short scales, reaches the typical proton wavelengths and drives the dynamics of particles. As a consequence of the interaction of particles with the turbulent fluctuating fields, the proton velocity distribution deviates significantly from the local thermodynamic equilibrium, the degree of deviation increasing with the level of turbulence in the system and being located near regions of strong magnetic stresses. These numerical results support recent space observations from the Magnetospheric MultiScale mission of ion kinetic effects driven by the turbulent dynamics at the Earth's magnetosheath (Perri et al., 2020, JPlPh, 86, 905860108) and by the Kelvin-Helmholtz instability in the Earth's magnetosphere (Sorriso-Valvo et al., 2019, PhRvL, 122, 035102).Comment: 14 pages, 11 figure

Investigations on Arthropods Associated with Decay Stages of Buried Animals in Italy

Burial could be used by criminals to conceal the bodies of victims, interfering with the succession of sarcosaprophagous fauna and with the evaluation of post-mortem interval. In Italy, no experimental investigation on arthropods associated with buried remains has been conducted to date. A first experimental study on arthropods associated with buried carcasses was carried out in a rural area of Arcavacata di Rende (Cosenza), Southern Italy, from November 2017 to May 2018. Six pig carcasses (Sus scrofa Linnaeus) were used, five of which were buried in 60-cm deep pits, leaving about 25-cm of soil above each carcass, and one was left above ground. One of the buried carcasses was periodically exhumed to evaluate the effects of disturbance on decay processes and on arthropod fauna. The other four carcasses were exhumed only once, respectively after 43, 82, 133, and 171 days. As expected, the decay rate was different among carcasses. Differences in taxa and colonization of arthropod fauna were also detected in the above ground and periodically exhumed carcasses. In carcasses exhumed only once, no arthropod colonization was detected. The results showed that a burial at about 25 cm depth could be sufficient to prevent colonization by sarcosaprophagous taxa and these data could be relevant in forensic cases involving buried corpses

Necrodes littoralis (Coleoptera: Silphidae) visiting and breeding on a carcass in Italy

The community that progressively colonizes a decaying corpse can be considered a small ecosystem mostly composed of sarcosaprophagous arthropods belonging to the orders Diptera and Coleoptera. Studies on these species are often performed through animal models to obtain data on their succession, behaviour and life cycle, together with information on habitat, corpse conditions, season and association with other species. These data may be relevant for forensic investigations, especially concerning the estimation of Post Mortem Interval (PMI). An investigation on the sarcosaprophagous insect community in a rural area was set in Calabria (Southern Italy), using a pig, Sus scrofa Linnaeus, 1758 (Artiodactyla: Suidae) as experimental model. Analyses of the community of Diptera and Coleoptera revealed the massive presence of Necrodes littoralis (Linnaeus, 1758) (Coleoptera: Silphidae). Adults of this species reached the carcass during the bloated stage and a large amount of larvae was detected from the decay stage onwards, simultaneous to the sharp decrease in dipteran larvae and pupae. The occurrence and the activity of N. littoralis should be considered to avoid misinterpretation and errors in estimating PMI in forensic investigation

Effects of Mechanical Winter Pruning on Vine Performances and Management Costs in a Trebbiano Romagnolo Vineyard: A Five-Year Study

Vineyard mechanical winter pruning has been spreading worldwide, and the physiological basis ascribable to it has been consolidated throughout the years. Despite labor savings and reduction of costs having been proven, the demonstration of its economic viability might be challenging. In this context, this work aims to evaluate the vine performances and the costs of different degrees of the mechanization of winter pruning over a five-year trial (2011-2015). In a vineyard of cv. Trebbiano Romagnolo (Vitis vinifera L.) located in northern Italy, three pruning treatments were laid out as follows: (a) manual pruning (MAN); (b) mechanical pre-pruning and simultaneous manual follow-up (MP + F); (c) mechanical pruning without a manual follow-up (MP). The results showed a strong increase in the node number of MP. Nevertheless, the yield compensation factors (i.e., the shoot fruitfulness and cluster weight) limited the increase in productivity. Soluble solids did not differ between the pruning treatments, while titratable acidity resulted slightly higher only on the MP berries. The MP treatment was the most economically convenient, with a vineyard surface of 1.5 hectares, while mechanical pruning with manual finishing resulted more advantageous, compared to manual pruning when the vineyard surface was greater than 2.9 hectares. The agronomic and economic results obtained in this five-year trial suggest that mechanical pruning may be profitably applied also on grapevine varieties characterized by low basal bud fruitfulness, such as Trebbiano Romagnolo

Fourier-Hermite decomposition of the collisional Vlasov-Maxwell system: Implications for the velocity-space cascade

Turbulence at kinetic scales is an unresolved and ubiquitous phenomenon that characterizes both space and laboratory plasmas. Recently, new theories, {\it in-situ} spacecraft observations and numerical simulations suggest a novel scenario for turbulence, characterized by a so-called phase space cascade -- the formation of fine structures, both in physical and velocity space. This new concept is here extended by directly taking into account the role of inter-particle collisions, modeled through the nonlinear Landau operator or the simplified Dougherty operator. The characteristic times, associated with inter-particle correlations, are derived in the above cases. The implications of introducing collisions on the phase space cascade are finally discussed