385 research outputs found

    Discussions on the relationships between meteorology and oceanography

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    G. E. R. DEACON: There must be some of you who, like me, did most of their seagoing 20 to 30 years ago and find it difficult to keep pace with the present urgency of introducing more precise reasoning into oceanography. This afternoon\u27s session dealing mainly with such precise arguments has not been easy to follow, and it is clear that there is much serious hard work ahead...

    A macroeconomics-inspired interpretation of the terrestrial water cycle

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    This article develops an approach that applies macroeconomic concepts to the interpretation of complex, water related natural processes. By translating and reinterpreting these processes into a language that is more accessible to a broader audience otherwise unaccustomed to its terms will likely help sharpen our understanding of the terrestrial water cycle. For economists, we describe climate-forming natural processes in a manner consistent with the fundamentals of the mainstream approach. For noneconomists, parallels from economically determined, relatively short-term observations can be applied conceptually to identify dynamics which occur over much longer and therefore more elusive natural occurrences, in particular considering the role of forests and how persistent land conversion over a millennium has shaped the earth's surface and impacted climate stability. The set of “supporting ecosystem services” highlighted in the Millennium Ecosystem Assessment (MEA) coincides with the ground phase of the terrestrial water cycle, taking the concept beyond the ecosystem service perspective and identifying it as a planetary service. Ecosystem and planetary services differ in the same way that microeconomic and macroeconomic perspectives do. The water cycle intensity of a geographical area may well be related to a rainfall multiplier that measures the ability of continental ecosystems to increase the amount of water moving across terrestrial surfaces and descending as rainfall through transpiration and deposition, and re-transpiration and re-deposition of the water content in the air that originally arrives from the oceans. Building upon the MEA's association of human wellbeing with ecosystem features, the rainfall multiplier serves as a physical indicator and measure of the natural basis of wellbeing creation

    Soil quality assessment based on soil organic matter pools under long‐term tillage systems and following tillage conversion in a semi‐humid region

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    A field study was conducted to assess the long-term effects of no-tillage (NT) and conventional tillage (CT), and the short-term effects following tillage conversion -from CT to NT (NTn) and from NT to CT (CTn) on soil quality (SQ) indicators in a semi-humid climate. First, plots of a long-term tillage experiment on a Luvic Phaeozem initiated in 1986, were split into two subplots in 2012, yielding four treatments: NT, CT, NTn and CTn. In 2015, composite soil samples were collected from each treatment and from a natural site (Ref) at depths 0-5, 5-10, 10-20 and 0-20 cm. Several indicators were determined: soil organic carbon (SOC) and nitrogen (SON); particulate organic C (POM-C) and N (POM-N); potential N mineralization (PMN) and soil respiration (Rs). Moreover, bulk density was determined in long-term tillage systems. Different ratios between indicators were calculated, with emphasis on its function in the agroecosystem, i.e. functional indicators. Significant differences in SOC, SON and PMN were found between CT and NT at most depths. In contrast, three years after tillage conversion, only a part of the SQ indicators studied were modified mainly at the 0-10 cm depth. The functional indicators showed differences between tillage systems in the long-term and after short-term tillage conversion depending on the depth; however, the PMN/SON ratio demonstrated differences at all depths. Under these conditions, this ratio -related to easily mineralizable N fraction- proved to be a promising indicator for assessing SQ under contrasting tillage systems regardless of the sampling depth.Fil: Martinez, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Galantini, Juan Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Duval, Matias Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: López, Fernando Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentin

    Synthesis of Biobased Diethyl Terephthalate via Diels-Alder Addition of Ethylene to 2,5-Furandicarboxylic Acid Diethyl Ester: An Alternative Route to 100% Biobased Poly(ethylene terephthalate)

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    Poly(ethylene terephthalate) (PET) is a ubiquitous thermoplastic currently produced from nonrenewable fossil resources; as such, sustainable biobased routes to the key terephthalate monomer are being widely pursued. Herein is demonstrated a greener solventless route to biobased diethyl terephthalate via a one-pot heterogeneous Lewis acid catalyzed Diels-Alder addition and dehydration of 2,5-furandicarboxylic acid diethyl ester with ethylene, giving yields of terephthalate up to 59% for the key Diels-Alder addition step. A metrics-based comparison against alternative published biobased routes (available from sugars, cellulose and hemicellulose) shows that the clean synthetic pathway developed herein gives a practical atom economy, overall yield and selectivity, making it a viable alternative to routes currently under development

    De-excitation of the strongly coupled band in 177Au and implications for core intruder configurations in the light Hg isotopes

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    Excited states in the proton-unbound nuclide 177Au were populated in the 92Mo(88Sr, p2n) reaction and identified using the Jurogam-II and GREAT spectrometers in conjunction with the RITU gas-filled separator at the University of Jyväskylä Accelerator Laboratory. A strongly coupled band and its decay path to the 11/2− α-decaying isomer have been identified using recoil-decay tagging. Comparisons with cranked HartreeFock-Bogoliubov (HFB) calculations based on Skyrme energy functionals suggest that the band has a prolate deformation and is based upon coupling the odd 1h11/2 proton hole to the excited 0+ 2 configuration in the 178Hg core. Although these configurations might be expected to follow the parabolic trend of core Hg(0+2 ) states as a function of neutron number, the electromagnetic decay paths from the strongly coupled band in 177Au are markedly different from those observed in the heavier isotopes above the midshell. This indicates that a significant change in the structure of the underlying A+1Hg core occurs below the neutron midshell
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