Dynamics and control of the expansion of finite-size plasmas produced in ultraintense laser-matter interactions

The strong influence of the electron dynamics provides the possibility of controlling the expansion of laser-produced plasmas by appropriately shaping the laser pulse. A simple irradiation scheme is proposed to tailor the explosion of large deuterium clusters, inducing the formation of shock structures, capable of driving nuclear fusion reactions. Such a scenario has been thoroughly investigated, resorting to two- and three-dimensional particle-in-cell simulations. Furthermore, the intricate dynamics of ions and electrons during the collisionless expansion of spherical nanoplasmas has been analyzed in detail using a self-consistent ergodic-kinetic model. This study clarifies the transition from hydrodynamic-like to Coulomb-explosion regimes

Expansion of nanoplasmas and laser-driven nuclear fusion in single exploding clusters

The expansion of laser-irradiated clusters or nanodroplets depends strongly on the amount of energy delivered to the electrons and can be controlled by using appropriately shaped laser pulses. In this paper, a self-consistent kinetic model is used to analyze the transition from quasineutral, hydrodinamic-like expansion regimes to the Coulomb explosion (CE) regime when increasing the ratio between the thermal energy of the electrons and the electrostatic energy stored in the cluster. It is shown that a suitable double-pump irradiation scheme can produce hybrid expansion regimes, wherein a slow hydrodynamic expansion is followed by a fast CE, leading to ion overtaking and producing multiple ion flows expanding with different velocities. This can be exploited to obtain intracluster fusion reactions in both homonuclear deuterium clusters and heteronuclear deuterium-tritium clusters, as also proved by three-dimensional molecular-dynamics simulations.Comment: 9 pages, 3 figures, to appear in Plasma Physics and Controlled Fusio

Confined gold nanoparticles enhance the detection of small molecules in label-free impedance aptasensors

A controlled architecture of nanoelectrodes, of a similar size to small molecule-binding aptamers, is synthesized inside nanoporous alumina. Gold nanoparticles with a controlled size (about 2 nm) are electrogenerated in the alumina cavities, showing a fast electron transfer process toward ferrocyanide. These uncapped nanoparticles are easily modified with a thiol-containing aptamer for label-free detection of adenosine monophosphate by electrochemical impedance spectroscopy. Our results show that the use of a limited electrical conducting surface inside an insulating environment can be very sensitive to conformational changes, introducing a new approach to the detection of small molecules, exemplified here by the direct and selective detection of adenosine monophosphate at the nanomolar scale.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures

Campo Experimental Potrok Aike : resultado de 15 años de labor técnica

Libro de edición impresa publicado en 2005 y con edición electrónica en el año 2016.Al crearse, en el año 1985, la Estación Experimental Santa Cruz en el marco del convenio entre el INTA y la provincia de Santa Cruz surgió la necesidad de contar con un campo donde se pudieran desarrollar trabajos de investigación en ganadería, fundamentalmente ovina, y en pastizales naturales con el necesario control de diferentes variables productivas y ambientales. El gobierno provincial cedió un predio ubicado al sur de la provincia de Santa Cruz, en una zona representativa de la Estepa magallánica seca, en el extremo austral de la Patagonia. Esta publicación recopiló y organizó los datos e información dispersa resultante de más de 15 años de trabajo, y transformó esa materia prima en información accesible para técnicos y productores. Conformada por el aporte de distintos autores ofrece la información de base para describir el ambiente del Campo Experimental Potrok Aike, más las conclusiones de ensayos y experiencias llevadas a cabo en el lugar, que son perfectamente extrapolables a todo el sur provincial.EEA Santa CruzFil: Alegre, María Beatriz. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Alegre, María Beatriz. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Alegre, María Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Anglesio, Francisco. Secretaría de Medio Ambiente. Provincia de Santa Cruz. Santa Cruz; Argentina.Fil: Baetti, Carlos. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Baetti, Carlos. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Bahamonde, Héctor Alejandro. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Bahamonde, Héctor Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Barría, Julio. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Battini, Alberto. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Baumann, Osvaldo. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Borrelli, Pablo. Consultor privado. Buenos Aires; Argentina.Fil: Camejo, Ana María. Consultor privado. Trelew; Argentina.Fil: Castillo, Miguel. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Cibils, Andrés. New México State University. Department of Animal and Range Sciences; Estados UnidosFil: Ciurca, Lorena. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Clifton, Guillermo Raimundo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Clifton, Guillermo Raimundo. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Culun, Victor Pascual. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Escalada, Julián. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Ferrante, Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Ferrante, Daniela. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Gismondi, Daniel. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: González, Liliana. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Grima, Daniel. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Humano, Gervasio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Iacomini, Mónica. Secretaría de la Producción. Provincia de Santa Cruz. Santa Cruz; Argentina.Fil: Iglesias, Roberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentina.Fil: Kofalt, Bustamante Rosa. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Kofalt, Bustamante Rosa. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Kofalt, Bustamante Rosa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Lamoureux, Mabel Noemi. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Lamoureux, Mabel Noemi. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Larrosa, José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Manero, Amanda. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Manero, Amanda. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Marcolín, Arrigo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina.Fil: Mascó, Mercedes. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Mascó, Mercedes. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Mascó, Mercedes. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Migliora, Horacio. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Milicevic, Francisco. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Montes, Leopoldo. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Patagonia Sur; Argentina.Fil: Oliva, Gabriel Esteban. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Oliva, Gabriel Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Osses, Julio Angel. Consejo Agrario Provincial- Provincia de Santa Cruz; Argentina.Fil: Paredes, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peinetti, Raúl. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina.Fil: Rial, Pablo Eduardo. Ministerio de Economía y Obras Públicas. Provincia de Santa Cruz; Argentina.Fil: Rial, Pablo Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Romero, Rubén. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Rosales, Valeria. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Salazar, Daniel. LU85 TV Canal 9. Auxiliar en Control de Erosión de Suelos. Provincia de Santa Cruz; Argentina.Fil: Tapia, Hector Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentina.Fil: Torra, Francisco. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Zerpa, Débora. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina

Bronze Age combustion structures of Italian contexts in comparison: Via Ordiere-Solarolo (Ravenna) and Mursia (Pantelleria island). Archaeological, geoarchaeological and experimental data

L’articolo prende in considerazione diverse fasi della ricerca relative all'uso del fuoco e alle pratiche di cottura in contesti domestici dell’età del Bronzo, utilizzando, per un approccio comparativo, le evidenze archeologiche rinvenute nei due insediamenti di Solarolo (RA) e di Mursia nell’isola di Pantelleria. Mentre nel primo caso l'evidenza delle strutture di cottura è scarsamente conservata e richiede campionamenti per analisi micromorfologiche e una complessa interpretazione, il secondo caso di Mursia, grazie alla migliore conservazione del deposito archeologico, permette di selezionare e ricostruire con maggiore facilità le caratteristiche coinvolte nella lavorazione e nella cottura dei cibi. Il contributo affronta il tema in modo altamente originale combinando diverse metodologie, raramente applicate nella descrizione delle strutture archeologiche connesse alla cottura dei cibi: oltre allo scavo stratigrafico documentato in dettaglio per la comprensione dei contesti sono state realizzate analisi micromorfologiche a sezione sottile, analizzate testimonianze etnoarcheologiche e applicate attività di riproduzione delle strutture e dei processi connessi alla produzione di alimenti cotti con metodi di archeologia sperimentale. Come richiesto dal processo scientifico dell’archeologia sperimentale sono illustrati in dettaglio i dati relativi alla costruzione delle strutture e al loro uso. Il contributo attende un ampio confronto nel dibattito sempre più intenso in ambito internazionale sulle attività svolte all’interno degli abitati protostorici e sui metodi di documentazione e analisi delle strutture archeologiche.Recent investigations carried out by the University of Bologna at the Bronze Age sites of Via Ordiere (Solarolo - Ravenna province) and Mursia (Pantelleria) discovered several types of fire installations. The paper considers different steps of the research related to the use of fire and cooking practices in domestic contexts using the two settlements for a comparative approach. While in the first case the evidence of firing structures is poorly pre-served and requires sampling for micromorphological analysis and complex analysis, the second case of Mursia, thanks to the best preservation of the archaeological deposit, allows to select and reconstruct more easily the features involved in processing and cooking food. Besides the presentation of the archaeological evidence, the research copes with the methods applied for a combination of results, including an archaeological protocol for documenting fire installations and the geo-archaeological analysis, extended to the comparison with similar features in the literature and with the ethno-archaeological evidence. A further approach was scheduled experimenting archaeological replica of most common fire installations. Finally, we deal a general understanding of the use of fire with a concept map going in depth with the many questions arisen pointing out the interrelationships among several parts of the process involving fire installations

La durata di vita degli abitati: attività e fasi costruttive tra analisi stratigrafica e cronologia

Nel contributo si vuole definire quali metodi e quali parametri possono essere applicati nel riconoscimento della durata di vita delle strutture di abitato. L’obiettivo del contributo rappresenta una vera e propria sfida nella ricerca archeologica: nella valutazione finale di un contesto di scavo di una struttura residenziale ci scontriamo spesso con l’incapacità di ottenere una precisione sufficiente per stabilire la durata delle strutture residenziali, e ci adattiamo a collocare nel tempo la durata delle fasi sulla base delle indicazioni deducibili dalla cultura materiale o dalla misurazione al radiocarbonioThe evidence of domestic or productive markers, as well as the structural transformations of each context help delimiting their duration. This paper aims to define what methods and parameters can be applied in the identification of the life span of inhabited structures. This target represents a real challenge in the archaeological research: in the final evaluation of excavated contexts of a residential structure we often encounter the inability to obtain sufficient precision to establish the duration of life of the residential structures or the effective time engaged in the activities. Usually, we constrain the duration of the phases along time based on the results from the material culture or from the radiocarbon measurement

Effects of cattle ingestion on viability and germination rate of calden (Prosopis caldenia) seeds

Caldén (Prosopis caldenia Burkart) is the dominant tree of the xerophytic open forest in the semiarid pampa of Argentina. caldén has gradually increased its distribution throughout the region during the past century as a result of livestock grazing in the pampa forest. Caldén has an indehiscent legume fruit that is consumed by livestock during the February-April fruit shedding period (FSP). Both free seeds and pod segments (1 seed inside the endocarp) can be found in cattle dung. Free seeds and pod segments coming from fruits (uningested) and dung (excreted) were collected during the fruit shedding period on 22 February (D1), 7 March (D2) and 27 March (D3) to compare viability and germination rate. Viabilities of uningested free seeds and pod segments averaged 95% and 65%, respectively, and were unaffected (P less than or equal to 0.01) by date of collection. Excreted free seed from D1 was 37% viable, which was lower (P less than or equal to 0.01) than the 72% viable for D2 and D3. Excreted pod segments averaged only 10% viable seeds. Ingestion increased (P less than or equal to 0.01) germination rate of free seed for D1 and D3. However, excreted seed displayed a range of delayed germination response. This diversity would increase the probability of seed germination for a variety of environmental and site conditions.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Le strutture di combustione ad uso alimentare nell’età del Bronzo. Dal record archeologico all’archeologia sperimentale

This article aims at analyzing ovens and cooking plates found in Italian prehistoric contexts. A multidisciplinary approach has been carried out to improve our understanding of finds from excavations carried out by the University of Bologna. An overview of previous researches is useful in preliminarily identifying manufacturing techniques and materials of these structures and their role in food production. More elaborate technical analyses and an experimental reproduction carried out during the activities of the Laboratory of Experimental Archaeology allowed a better understanding of the processeses involved, and, most significantly, to enhance the identification of traces of cooking activities during archaeological excavations. Ethnoarchaeology and archaeometry thus seem to be among the most qualified disciplines to investigate this kind of evidence and to design an ontological classification of prehistoric structures