Search results for "Ash"

THE ROLE OF CYTOKININS AND ETHYLENE INHIBITORS ON LENTICEL HYPERTROPHY GENERATION AND ETHYLENE PRODUCTION IN IN VITRO CULTURES OF POPULUS EUPHRATICA …

1995

Populus euphratica Olivier is native to the Irano—Turanian areas (Middle East). Elche (Alicante province, SE Spain) is known to be its only European location. Nodal segments from root shoots were established in vitro in a Murashige and Skoog medium supplemented with several cytokinins. Ethylene inhibitors AgNO3 and CoCl2 were used in combination with kinetin. Hormone-free media supplemented with sucrose (20–60 mg 1−1) was also tested. Ethylene was measured by gas chromatography, and both the percentage of sprouting shoots and lenticel hypertrophy in cultures were recorded. Ethylene production was higher in cultures supplemented with cytokinins (especially with meta-topolin), with high sprou…

Trace element mobility during interaction between rain and volcanic ash on Mt. Etna

2012

Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere, both during and between eruptions. Due to their potential toxicity they may have important environmental impacts from the local to the global scale. Atmospheric precipitation was collected approximately every two weeks, from April 2006 to December 2007, using a network of five rain gauges, located at various altitudes on the upper flanks around the summit craters of Etna volcano. The collected samples were analysed for major (Ca, Mg, K, Na, F, SO4, Cl, NO3) and a large suite of trace elements (Ag, Al, As, Au, B, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Fe, Hg, La, Li, Mn, Mo, Ni, Pb, Rb, Si, S…

Evolutionary design optimization with Nash games and hybridized mesh/meshless methods in computational fluid dynamics

2012

The photophysics and photochemistry of cofacial free base and metallated bisporphyrins held together by covalent architectures

2007

Abstract This review focuses on the photophysical properties of bisporphyrin systems held in a face-to-face configuration by covalent bonds via flexible or rigid spacers and metal–metal bonds. The cofacial arrangement induces intramolecular bismacrocycle interactions promoting basic photophysical events such as excitonic interactions and energy and electron transfers. These events are relevant to mimic light harvesting and reactor devices known for photosynthesis in plants, and can be monitored by luminescence and flash photolysis methods.

CEO Compensation and Risk-Taking: Evidence from Listed European Hotel Firms

2020

This paper examines the relationship between CEO compensation policies and financial performance in the European hotel sector. We analyze CEO cash-, equity- and total-compensation relationships with two accounting-based and two market-based financial performance proxies, including a bi-dimensional proxy formed by stock market return and risk. This bi-dimensional market-based financial performance proxy enables us to take a deep dive into the relationship between CEO compensation policies and firm risk-taking. We then analyze the nature of this relationship by decomposing market-based risk into systematic and idiosyncratic risk, using five alternative asset-pricing factorial models. Our resu…

On thermoeconomics of energy systems at variable load conditions: integrated optimization of plant design and operation

2007

Abstract Thermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems, its different methodologies allowing solution of problems in the fields of cost accounting, plant design optimisation and diagnostic of malfunctions. However, the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasi-steady operation, but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper, the fundamentals of thermoeconomics for systems operated at variable load are discussed, examining the cost formation process an…

Let's bring blacks home! Imaginación colonial y formas de aproximación gráfica de los negros de África (1880-1968)

2020

La dominación colonial europea en territorios de África, revestida de acción civilizadora.

Flush-Crash Experiments in Drosophila

1989

In 1968, Hampton Carson (1968) proposed the founder-flush-crash model, a new model of speciation, which readily lends itself to experimental testing in the laboratory (Carson 1971).

From material flows to cash flows — an extension to traditional material flow modelling

2000

Shape optimization of high-energy absorbers

2018

In this paper, a new approach to simulate and to optimize the performances of a crash-box, in terms of energy absorption or acceleration peak, is presented. As soon as the maximum size of the crash-box (longitudinal and transversal dimensions) has been fixed, the new approach allows optimizing the shape of the transversal section and the thickness of the structure. Thanks to the proposed procedure, engineers can easily identify the best crash-box depending on the particular working conditions. The new method has been tested with different cases study by considering different objective functions. The obtained results show the procedure works well and also demonstrate that the optimal number …