180 research outputs found

    Biotechnical characteristics of root systems in erect and prostrate habit rosmarinus officinalis L. accessions grown in a mediterranean climate

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    Rosmarinus officinalis L. is a shrub species typically found in the Mediterranean Basin area. Studies carried out in Sicily on the biodiversity of the genus Rosmarinus found only one species (Rosmarinus officinalis L.) with varying morphology (erect habit and prostrate habit). The species does not require high input, managing to thrive even in marginal areas, and is a medicinal and aromatic species of great agronomic and economic interest, being one of the top 20 species most-used in Italy and with highest wholesale revenues. Studies carried out on the species in Italy are recent, as is the whole medicinal and aromatic plants sector, and have mostly regarded agrotechniques. This study shows the results of initial observations carried out in Sicily on the biotechnical characteristics of the root system of disetaneous rosemary accessions (erect habitus and prostrate habitus) grown in the same soil. Results show that the species adapts well to soil bioengineering requirements; young plants also showed better root system tensile strength than older plant

    Qualità pomologica e sensoriale di 10 varietà di mango (Mangifera indica L.) coltivate in Sicilia

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    Il mango (Mangifera indica L.) è una pianta arborea originaria della regione Indo-Burmese, che appartiene botanicamente alla famiglia delle Anacardiaceae, principalmente coltivata nei paesi a clima tropicale e subtropicale ed oggi, complice il cambiamento climatico, diffusa anche nel bacino del mediterraneo. In Italia il mango viene coltivato solo in Sicilia dove areali della costiera tirrenica hanno fatto registrare produzioni di pregio e una crescente diffusione di nuove cultivar provenienti dai luoghi di origine. Limiti vegetazionali piuttosto stretti, soprattutto in termini di minime termiche stagionali, hanno, in passato, causato l’insuccesso di numerosi nuovi impianti basati sull’introduzione di varietà inedite negli areali a clima mediterraneo-subtropicale come in Sicilia. Per evitare il verificarsi di tali situazioni occorre, quindi, valutare con attenzione il comportamento vegeto-produttivo delle nuove introduzioni varietali. Il presente lavoro ha avuto come obiettivo quello di valutare l’adattamento di 10 cultivar di mango mettendo in relazione gli stadi fenologici con gli andamenti termici stagionali utilizzando la scala BBCH (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie) e valutando la qualità fisico-chimica dei frutti. Per ciascun frutto delle 10 varietà in esame sono state analizzate le seguenti caratteristiche: peso del frutto, diametro trasversale del frutto, diametro longitudinale del frutto, consistenza della polpa, peso della polpa, peso della buccia, peso del seme, diametro trasversale del seme, diametro longitudinale del seme. Del succo di ogni frutto sono stati analizzati il contenuto in solidi solubili e l’acidità titolabile. Le prove sono state svolte presso l’azienda Cupitur sita in Caronia Marina, provincia di Messina. Le cv prese in esame sono state: Glenn, Osteen, Maya, Nam Dok Mai, Irwin, Calypso, Valencia Pride, Keitt, Kent e Tommt Atkyns. La correlazione tra stadi fenologici e temperatura nonché il confronto con i risultati ottenuti in ambienti vocati indicano che, seppur con alcuni limiti legati all’inverno, le aree della costa tirrenica della Sicilia, dove queste varietà sono state coltivate, risultano un ambiente climaticamente idoneo per il corretto evolversi delle fasi vegetative e produttive e l’ottenimento di frutti dalle interessanti qualità organolettiche. Tuttavia, l’analisi dei dati di questo ultimo anno ha evidenziato alcune problematiche in grado di influenzare negativamente lo sviluppo delle piante. Temperature al di sotto dei valori critici, infatti, ci obbligano all’uso di frangivento, per ridurre il rischio di esposizione a venti freddi, e al ricorso ad apprestamenti protettivi delle singole piante nei primi anni dell’impianto. Dalle analisi pomologiche risulta un’ampia variabilità delle caratteristiche fisico-chimiche in grado di offrire una ampia scelta commerciale. L’introduzione di queste nuove cultivar in Sicilia consentirebbe un ampliamento del calendario di maturazione da agosto fino a novembre, limitando il ricorso all’importazione, ma va ulteriormente approfondito in relazione ai fattori sopra esposti

    Miniaturized Low-Voltage Power Converters With Fast Dynamic Response

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    This paper demonstrates a two-stage approach for power conversion that combines the strengths of variable-topology switched capacitor techniques (small size and light-load performance) with the regulation capability of magnetic switch-mode power converters. The proposed approach takes advantage of the characteristics of complementary metal-oxide-semiconductor (CMOS) processes, and the resulting designs provide excellent efficiency and power density for low-voltage power conversion. These power converters can provide low-voltage outputs over a wide input voltage range with very fast dynamic response. Both design and fabrication considerations for highly integrated CMOS power converters using this architecture are addressed. The results are demonstrated in a 2.4-W dc-dc converter implemented in a 180-nm CMOS IC process and co-packaged with its passive components for high performance. The power converter operates from an input voltage of 2.7-5.5 V with an output voltage of ≤1.2 V, and achieves a 2210 W/in[superscript 3] power density with ≥80% efficiency.Focus Center Research ProgramUnited States. Defense Advanced Research Projects AgencySemiconductor Research CorporationCharles Stark Draper Laborator

    Observations of the cold wake of Typhoon Fanapi (2010)

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    Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 316–321, doi:10.1029/2012GL054282.Several tens of thousands of temperature profiles are used to investigate the thermal evolution of the cold wake of Typhoon Fanapi, 2010. Typhoon Fanapi formed a cold wake in the Western North Pacific Ocean on 18 September characterized by a mixed layer that was >2.5 °C cooler than the surrounding water, and extending to >80 m, twice as deep as the preexisting mixed layer. The initial cold wake became capped after 4 days as a warm, thin surface layer formed. The thickness of the capped wake, defined as the 26 °C–27 °C layer, decreased, approaching the background thickness of this layer with an e-folding time of 23 days, almost twice the e-folding lifetime of the Sea Surface Temperature (SST) cold wake (12 days). The wake was advected several hundreds of kilometers from the storm track by a preexisting mesoscale eddy. The observations reveal new intricacies of cold wake evolution and demonstrate the challenges of describing the thermal structure of the upper ocean using sea surface information alone.This work is primarily supported by the U.S. Office of Naval Research, with additional support from the National Science Foundation and the National Science Council, Taiwan

    The LatMix summer campaign : submesoscale stirring in the upper ocean

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    Author Posting. © American Meteorological Society, 2015. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 96 (2015): 1257–1279, doi:10.1175/BAMS-D-14-00015.1.Lateral stirring is a basic oceanographic phenomenon affecting the distribution of physical, chemical, and biological fields. Eddy stirring at scales on the order of 100 km (the mesoscale) is fairly well understood and explicitly represented in modern eddy-resolving numerical models of global ocean circulation. The same cannot be said for smaller-scale stirring processes. Here, the authors describe a major oceanographic field experiment aimed at observing and understanding the processes responsible for stirring at scales of 0.1–10 km. Stirring processes of varying intensity were studied in the Sargasso Sea eddy field approximately 250 km southeast of Cape Hatteras. Lateral variability of water-mass properties, the distribution of microscale turbulence, and the evolution of several patches of inert dye were studied with an array of shipboard, autonomous, and airborne instruments. Observations were made at two sites, characterized by weak and moderate background mesoscale straining, to contrast different regimes of lateral stirring. Analyses to date suggest that, in both cases, the lateral dispersion of natural and deliberately released tracers was O(1) m2 s–1 as found elsewhere, which is faster than might be expected from traditional shear dispersion by persistent mesoscale flow and linear internal waves. These findings point to the possible importance of kilometer-scale stirring by submesoscale eddies and nonlinear internal-wave processes or the need to modify the traditional shear-dispersion paradigm to include higher-order effects. A unique aspect of the Scalable Lateral Mixing and Coherent Turbulence (LatMix) field experiment is the combination of direct measurements of dye dispersion with the concurrent multiscale hydrographic and turbulence observations, enabling evaluation of the underlying mechanisms responsible for the observed dispersion at a new level.The bulk of this work was funded under the Scalable Lateral Mixing and Coherent Turbulence Departmental Research Initiative and the Physical Oceanography Program. The dye experiments were supported jointly by the Office of Naval Research and the National Science Foundation Physical Oceanography Program (Grants OCE-0751653 and OCE-0751734).2016-02-0

    Eddy-driven subduction exports particulate organic carbon from the spring bloom

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    The export of particulate organic carbon (POC) from the surface ocean to depth is traditionally ascribed to sinking. Here, we show that a dynamic eddying flow field subducts surface water with high concentrations of nonsinking POC. Autonomous observations made by gliders during the North Atlantic spring bloom reveal anomalous features at depths of 100 to 350 meters with elevated POC, chlorophyll, oxygen, and temperature-salinity characteristics of surface water. High-resolution modeling reveals that during the spring transition, intrusions of POC-rich surface water descend as coherent, 1- to 10-kilometer–scale filamentous features, often along the perimeter of eddies. Such a submesoscale eddy-driven flux of POC is unresolved in global carbon cycle models but can contribute as much as half of the total springtime export of POC from the highly productive subpolar oceans

    EXPORTS North Atlantic eddy tracking

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    The EXPORTS North Atlantic field campaign (EXPORTS-NA) of May 2021 used a diverse array of ship-based and autonomous platforms to measure and quantify processes leading to carbon export in the open ocean. The success of this field program relied heavily on the ability to make measurements following a Lagrangian trajectory within a coherent, retentive eddy (Sections 1, 2). Identifying an eddy that would remain coherent and retentive over the course of a monthlong deployment was a significant challenge that the EXPORTS team faced. This report details the processes and procedures used by the primarily shore-based eddy tracking team to locate, track, and sample with autonomous assets such an eddy before and during EXPORTS-NA.This field deployment was funded by the NASA Ocean Biology and Biogeochemistry program and the National Science Foundation Biological and Chemical Oceanography programs. Initial gliders deployments were performed by the RRS Discovery and the authors thank the Porcupine Abyssal Plain – Sustained Observatory of the Natural Environment Research Council (NERC, UK), which is principally funded through the Climate Linked Atlantic Sector Science (CLASS) project supported by NERC National Capability funding (NE/R015953/1) and by IFADO (Innovation in the Framework of the Atlantic Deep Ocean) EAPA_165/2016. Technical assistance with glider deployment was provided by Marine Autonomous Robotic Systems (NOC). The authors thank Inia Soto Ramos for assistance in publishing this manuscript through the NASA Technical Memorandum series. This is PMEL contribution number 5372

    Injection of oxygenated Persian Gulf Water into the southern Bay of Bengal

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    Persian Gulf Water (PGW) is an oxygenated, high-salinity water mass that has recently been detected in the Bay of Bengal (BoB). However, little is known about the transport pathways of PGW into the BoB. Ocean glider observations presented here demonstrate the presence of PGW in the southwestern BoB. Output from an ocean reanalysis product shows that this PGW signal is associated with a northward-flowing filament of high-salinity water. Particle tracking experiments reveal two pathways: one in the eastern Arabian Sea that takes a minimum of 2 years and another in the western Arabian Sea that takes a minimum of 3 years. The western pathway connects to the BoB via equatorial currents. The greatest influx of PGW occurs between 82° and 87°E during the southwest monsoon. We propose that injection of PGW to the BoB oxygen minimum zone (OMZ) contributes to keeping oxygen concentrations in the BoB above the level at which denitrification occurs
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