Numerical wave interaction with tetrapods breakwater

ABSTRACT: The paper provides some results of a new procedure to analyze the hydrodynamic aspects of the interactions between maritime emerged breakwaters and waves by integrating CAD and CFD. The structure is modeled in the numerical domain by overlapping individual three-dimensional elements (Tetrapods), very much like the real world or physical laboratory testing. Flow of the fluid within the interstices among concrete blocks is evaluated by integrating the RANS equations. The aim is to investigate the reliability of this approach as a design tool. Therefore, for the results' validation, the numerical run-up and reflection effects on virtual breakwater were compared with some empirical formulae and some similar laboratory tests. Here are presented the results of a first simple validation procedure. The validation shows that, at present, this innovative approach can be used in the breakwater design phase for comparison between several design solutions with a significant minor cost. KEY WORDS: Volume of Fluid (VOF), Wave, Run up, Reflection, Rubble mound, Numerical simulations, Tetrapod Flow 3D®, RANS equation

La capacità repressiva di compost nei confronti della tracheofusariosi del basilico

Alcuni compost, addizionati al suolo o impiegati come componenti di substrati per colture in vaso, possono svolgere un’attività repressiva nei confronti dei patogeni terricoli. Nel biennio 2005-2006 sono stati saggiati, a Grugliasco (TO), in serre in ferro/vetro, compost provenienti da aziende di compostaggio presenti sul territorio piemontese al fine di valutarne la loro capacità repressiva. Dai risultati è emerso l’efficace contenimento nei confronti di F. oxysporum f.sp. basilici, da parte di compost prodotto a partire da rifiuti solidi urbani e fanghi, con una diminuzione fino al 50% di piante morte e un incremento fino al 25% di biomassa prodotta a fine ciclo rispetto a quanto rilevato impiegando un ammendante torboso scelto come riferimento

Calcium oxide, potassium phosphite and a Trichoderma enriched compost water suspension protect Capsicum annuum against Phytophthora capsici by priming the immune system

BACKGROUND: Proper management of Phytophthora capsici in pepper cultivation is extremely important, since Phytophthora blight is the main disease of this crop worldwide. In the past, the main strategy adopted had been the use of fungicides, causing, in some cases, the development of P. capsici resistant strains. In this work three different treatments selected from previous studies (potassium phosphite, calcium oxide and a water suspension from Trichoderma sp. TW2 enriched compost) were tested to prove their ability to activate the systemic acquired resistance (SAR) in pepper against P. capsici; acibenzolar‐s‐methyl was used as positive control. Two independent growth chamber pot experiments were performed, spatially dividing the site of treatments application (as radical drench) and the site of inoculation (as agar plug on the third leaf). RESULTS: Leaf lesions were measured, showing a significant reduction on all treated plants compared to the untreated control. To further confirm this hypothesis, the expression levels of three SAR key genes (CaPBR1, CaPO1 and CaDEF1) were evaluated though RT‐Real Time PCR at the three end‐point times: T0, T6 and T24. A significant increase of target genes expression at least in one end‐point time in each treated plant was observed. Eventually, statistical overaccumulation of salicylic acid was observed in the upper leaves at the same end‐point times, through HPLC‐MS/MS analysis. CONCLUSION: This work confirmed the hypothesis that the three treatments tested have the ability to prime the plant immune system, leading pepper to an alert status able to confer a better defence against P. capsici. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry

Toward the fabrication of extruded microstructured bioresorbable phosphate glass optical fibers

The steps toward the fabrication of directly extruded microstructured fiber preforms made of a bioresorbable phosphate glass are herein presented, analyzing the features of the process from the glass synthesis to the manufacturing of the fiber. The realization of these fibers leverages on three main pillars: an optically transparent bioresorbable glass, its extrusion into a preform, and the fiber drawing. The glass has been designed and carefully prepared in our laboratory to be dissolvable in a biological fluid while being optically transparent and suitable for both preform extrusion and fiber drawing. To support the production of an optimized die for the preform extrusion, a simplified laminar flow model simulation has been employed. This model is intended as a tool for a fast and reliable way to catch the complex behavior of glass flow during each extrusion and can be regarded as an effective design guide for the dies to fulfill the specific needs for preform fabrication. After die optimization, extrusion of a capillary was realized, and a stacking of extruded tubes was drawn to produce a microstructured optical fiber made of bioresorbable phosphate glass