326 research outputs found
Comparing the usefulness of assessment tools for environmental impacts evaluation of organic greenhouse horticulture
Organic farming is primarily meant to be sustainable; however, evaluating the sustainability of farming systems in a complete way is a complex issue. In recent years, a high number of sustainability assessment tools has been developed and used worldwide; nevertheless, even if they differ in terms of analysis depth, none of them seems comprehensive enough. Amongst all the existing tools we have chosen two of them, Life Cycle Assessment (LCA) and Public Goods Tool (PGT). In the case of specific farming systems such as organic greenhouse horticulture, a comparison between LCA and PGT has been done to evaluate the potential integration between both sets of results so that a single holistic assessment method could be obtained. This could help to understand which sustainability aspect these methods should focus on and which type and depth of data would be desirable. This paper mainly highlights the methodological differences and potential common points between the tools, referring to a chosen case study (Tolhurst Organic, a stockfree horticultural unit located near Reading, UK) that has been assessed with both, and then gives suggestions for future research. An updated and improved version of the LCA Excel tool, initially developed by the EUphoros project (2008-2012) and then integrated with data from PGT, was the main outcome of the comparison. While LCA gives quantitative results on impacts on key environmental categories, PGT shows ways to improve farming practices regarding a set of social, economic and environmental aspects through a simple scoring system. In this sense, trying to combine results from different assessment tools might be difficult because it highlights the lack of overall complementarity between them, but at the same time it could be a useful starting point for an integrated discussion on production, use of natural resources and improvements of practices among decision-makers.Publisher Statement: The original publication is available at www.actahort.org, https://dx.doi.org/10.17660/ActaHortic.2017.1164.63 </p
A new physeteroid cetacean from the Lower Miocene of southern Italy: CT imaging, retrodeformation, systematics and palaeobiology of a sperm whale from the Pietra leccese
Herein we describe a new finding of a medium-sized sperm whale from the Burdigalian (Lower Miocene) of the Pietra leccese formation (southern Italy) on the basis of a partly prepared specimen that includes a partial cranium, seven detached teeth, the fragmentary right mandible and two partial vertebral bodies. Because of the overall compression of the specimen, we carried out a retro deformation of a 3D model of the cranium obtained via CT-scanning. The combined analysis of the original specimen and the retrodeformed model has allowed us to recognise that the studied specimen constitutes a new physeteroid taxon: Angelocetus cursiensis n. gen. n. sp., a longirostrine sperm whale characterised by a sideward projected supracranial basin, as evidenced by the overall displacement of its posteriormost margin. Based on a phylogenetic analysis, A. cursiensis n. gen. n. sp. is determined to be a crown physeteroid that does not belong to either the Physeteridae or the Kogiidae. The wide temporal fossa, elongated rostrum and slender teeth, as well as the skull dimensions (estimated bizygomatic width c. 550 mm) suggest a diet based on medium to large-sized bony fish that were likely captured by a raptorial pierce feeding strategy (as for most of the coeval Burdigalian physeteroids). Despite a seemingly low ecomorphological disparity, the high degree of taxonomic diversity of the Burdigalian physeteroids suggests that this time span represents a crucial phase for the evolutionary history of sperm whales
Benthic foraminiferal record of paleoenvironmental changes in the Langhian St. Peter’s Pool section (Malta Island)
Age and Depositional Environment of Whale-Bearing Sedimentary Succession from the Lower Pliocene of Tuscany (Italy): Insights from Palaeomagnetism, Calcareous Microfossils and Facies Analyses
A c. 31 m thick section straddling the fossil find of an Early Pliocene baleen whale ("Brunella", hereafter), made in 2007 in the sedimentary fill of the Middle Ombrone Basin of Tuscany, is investigated for depositional age and environment combining palaeomagnetic, micropalaeontological (Foraminifera and calcareous nannofossils) and sedimentary facies analyses. Resting unconformably onto Late Miocene continental deposits, the Early Pliocene marine deposits include, from bottom to top, a coarse-grained wave-winnowing lag, the few metres-thick fossiliferous sandstone bedset from which Brunella was unearthed, and several metres of clays. The stratigraphic organisation of these deposits indicate deposition in a deepening upward inner shelf environment. Successful isolation of characteristic remanent magnetisation and calcareous nannofossil content indicate the investigated marine section was deposited during the interval of polarity Chron C3n.2n corresponding to the basal part of the Mediterranean nannofossil zone MNN13 (between Helicosphaera sellii Base common and the Amaurolithus primus Top) and allow estimating the depositional age of Brunella to c. 4.6 Ma. Sedimentary facies, benthic Foraminifera association and anisotropy of magnetic susceptibility characterising the deposits that embedded Brunella suggest deposition above the fair-weather base level
Controles y comportamiento de instalaciones de sistemas fotovoltaicos en escuelas rurales de Catamarca, Argentina
En la provincia de Catamarca, Argentina, entre los años 2006 y 2008 se instalaron 38 sistemas fotovoltaicos para provisión de energía eléctrica a escuelas rurales del interior. La obra, realizada por licitación internacional, contemplaba la posibilidad del pago de equipos en acopio, independiente de las tareas de montaje, por lo cual desde la Unidad Ejecutora Provincial se decidió instrumentar diferentes controles para la recepción de la misma. En el presente trabajo se muestran algunos ensayos previos sobre componentes de las instalaciones, los primeros controles de los sistemas completos funcionando in situ y los resultados del monitoreo en funcionamiento bajo condiciones reales de uso. A pesar que algunos componentes, en las pruebas preliminares se ajustaban a las exigencias, durante el periodo de funcionamiento se comprobó que no son los más adecuados para este tipo de instalaciones. Los módulos fotovoltaicos, los reguladores y las baterías presentaron un excelente comportamiento en 8 años de funcionamiento
Nanostructures Technology, Research, and Applications
Contains reports on twenty-four research projects and a list of publications.Joint Services Electronics Program Grant DAAHO4-95-1-0038Defense Advanced Research Projects Agency/Semiconductor Research Corporation SA1645-25508PGU.S. Army Research Office Grant DAAHO4-95-1-0564Defense Advanced Research Projects Agency/U.S. Navy - Naval Air Systems Command Contract N00019-95-K-0131Suss Advanced Lithography P. O. 51668National Aeronautics and Space Administration Contract NAS8-38249National Aeronautics and Space Administration Grant NAGW-2003Defense Advanced Research Projects Agency/U.S. Army Research Office Grant DAAHO4-951-05643M CorporationDefense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research Contract N66001-97-1-8909National Science Foundation Graduate FellowshipU.S. Army Research Office Contract DAAHO4-94-G-0377National Science Foundation Contract DMR-940034National Science Foundation Grant DMR 94-00334Defense Advanced Research Projects Agency/U.S. Air Force - Office of Scientific Research Contract F49620-96-1-0126Harvard-Smithsonian Astrophysical Observatory Contract SV630304National Aeronautics and Space Administration Grant NAG5-5105Los Alamos National Laboratory Contract E57800017-9GSouthwest Research Institute Contract 83832MIT Lincoln Laboratory Advanced Concepts ProgramMIT Lincoln Laboratory Contract BX-655
Toward an Astrochronology-Based Age-Model for a Messinian Pre-Evaporitic Succession: The Example of Torrente Vaccarizzo Section in Sicily (Italy)
Tectonic, paleoenvironmental, and paleoclimatic unstable conditions preceding the onset of the Messinian Salinity Crisis (MSC) highly affected marine life. Changes in calcareous plankton association are overall registered in the Mediterranean. They consist of a general transition from abundant and well-diversified planktonic associations to strictly oligotypic assemblages that precede their total disappearance at the onset of evaporitic precipitation. In this work, an accurate quantitative analysis of calcareous plankton, both foraminifers and nannofossils, has been carried out in the Torrente Vaccarizzo Section of Sicily (southern Italy). The aim is to independently define a chronostratigraphic pattern of bioevents preceding the MSC in the absence of magnetostratigraphic or radiometric constraints. The fluctuating abundance of the genus Orbulina fits well with the 100 ky Eccentricity maxima, and it is successfully applied to build an astronomically calibrated age-model for the section. On this basis, all the biohorizons have been recalibrated and discussed with regard to the previous literature. Abundant influxes of selected species demonstrated to be of local significance since they are highly affected by paleoenvironmental and paleoclimatic conditions. A chronological sequence of foraminifer and nannofossil events marks the onset of the MSC with a derived age of 5.957 My, which agrees well with previous findings from other Mediterranean sections. This methodology and the new biostratigraphic events may be useful for future studies on pre-evaporitic successions of the Mediterranean
Nanostructures, Technology, Research, and Applications
Contains reports on twenty research projects and a list of publications.Joint Services Electronics Program Grant DAAH04-95-1-0038National Science Foundation Grant ECS-94-07078Semiconductor Research CorporationU.S. Army Research Office Grant DAAH04-95-1-0564Defense Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-95-K-0131National Aeronautics and Space Administration Contract NAS8-38249National Aeronautics and Space Administration Grant NAGW-2003IBM Corporation Contract 1622National Science Foundation Graduate FellowshipU.S. Navy - Office of Naval Research Grant N00014-95-1-1297U.S. Army Research Office Contract DAAH04-94-G-0377U.S. Air Force - Office of Scientific Research Grant F49620-92-J-0064U.S. Air Force - Office of Scientific Research Grant F49620-95-1-0311National Science Foundation Contract DMR 94-0034U.S. Air Force - Office of Scientific Research Contract F49620-96-0126Harvard-Smithsonian Astrophysical Observatory Contract SV630304National Aeronautics and Space Administration Grant NAG5-5105Los Alamos National Laboratory Contract E57800017-9
Terahertz All-Optical Modulation in a Silicon-Polymer Hybrid System
Although Gigahertz-scale free-carrier modulators have been previously
demonstrated in silicon, intensity modulators operating at Terahertz speeds
have not been reported because of silicon's weak ultrafast optical
nonlinearity. We have demonstrated intensity modulation of light with light in
a silicon-polymer integrated waveguide device, based on the all-optical Kerr
effect - the same ultrafast effect used in four-wave mixing. Direct
measurements of time-domain intensity modulation are made at speeds of 10 GHz.
We showed experimentally that the ultrafast mechanism of this modulation
functions at the optical frequency through spectral measurements, and that
intensity modulation at frequencies in excess of 1 THz can be obtained in this
device. By integrating optical polymers through evanescent coupling to
high-mode-confinement silicon waveguides, we greatly increase the effective
nonlinearity of the waveguide for cross-phase modulation. The combination of
high mode confinement, multiple integrated optical components, and high
nonlinearities produces all-optical ultrafast devices operating at
continuous-wave power levels compatible with telecommunication systems.
Although far from commercial radio frequency optical modulator standards in
terms of extinction, these devices are a first step in development of
large-scale integrated ultrafast optical logic in silicon, and are two orders
of magnitude faster than previously reported silicon devices.Comment: Under consideration at Nature Material
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