Search results for "Surface Processes"
showing 10 items of 1294 documents
Sediment Transport and Hydrodynamic Parameters of Tsunami Waves Recorded in Onshore Geoarchives
2014
In regions with a short historical tsunami record, the assessment of long-term tsunami risk strongly depends on geological evidence of prehistoric events. Whereas dating tsunami deposits is already well established, magnitude assessment based on remaining sedimentary structures is still a major challenge. In this study, two approaches were applied to deduce transport processes and hydrodynamic parameters of tsunami events from onshore deposits found in the coastal plain of Ban Bang Sak, SW Thailand: (1) The maximum offshore sediment source was determined using granulometry, geochemistry, mineralogy and foraminifera of the tsunamites, and reference samples from various marine and terrestrial…
Use of large Acacia trees by the cavity dwelling Black-tailed Tree Rat in the Southern Kalahari
2006
Recent extensive harvesting of large, often dead Acacia trees in arid savanna of southern Africa is cause for concern about the conservation status of the arid savanna and its animal community. We mapped vegetation and nests of the Black-tailed Tree Rat Thallomys nigricauda to assess the extent to which the rats depend on particular tree species and on the existence of dead, standing trees. The study was conducted in continuous Acacia woodland on the southern and eastern edge of the Kalahari, South Africa. Trees in which there were tree rat nests were compared with trees of similar size and vigour to identify the characteristics of nest sites. Spatial analysis of tree rat distribution was c…
Aridity level, rainfall pattern and soil features as key factors in germination strategies in salt-affected plant communities
2015
Abstract In arid environments, particularly in halophytic habitats, germination ecophysiology is strongly affected by environmental factors, primarily water availability, which is influenced by quantity and seasonal distribution of precipitation and soil properties. The aim of this paper was to demonstrate that water availability is essential for the control of germination and the response of seedlings growing in saline areas. With this approach, we compared the germination strategies in two Halocnemum populations with contrasting rainfall regimes and soil aridity. The germination behavior and radicle growth under various temperature regimes, light conditions and salinity levels were evalua…
Stable isotope analysis of well-preserved 120,000-year-old herbivore bone collagen from the Middle Palaeolithic site of Neumark-Nord 2, Germany revea…
2012
Abstract Herbivores from the Neumark-Nord 2 archaeological site, Germany, were analysed for bone collagen stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope ratios in order to investigate feeding ecology at this early Last Interglacial (Eemian) shallow-lake site. Of 42 faunal samples selected, 23 yielded collagen, demonstrating remarkable preservation for material of this age. The results indicate clear inter-specific differences in δ 15 N and δ 13 C values, notably between equids ( Equus ) and bovids ( Bos/Bison ), with mean difference Δ 15 N of + 2‰ measured in the bovids compared to the equids. The potential reasons for these differences are explored, including physiology, herbivore fe…
The last glacial/interglacial record of rodent remains from the Gigny karst sequence in the French Jura used for palaeoclimatic and palaeoecological …
1995
Abstract A multidisciplinary approach has produced an exceptional chronological log of climatic patterns for the Upper Pleistocene sequence of Gigny Cave (Jura, France) covering the Pre-Eemian, Eemian Interglacial, Middle Glacial and Upper Pleniglacial, as well as a part of the Holocene. Multivariate analysis (correspondence and component analysis) of rodent associations from the sequence is used here to characterize the different climatic stages in terms of relative temperature, plant cover and moisture. Faunal analysis establishes: (1) positive and negative correlations among the variations of the different species; (2) the significance of axis 1 (component analysis) which, in terms of te…
A numerical study of the Schumann resonances in Mars with the FDTD method
2007
[1] Natural electromagnetic waves generated near the surface by electrostatic discharges in dust storms (dust devils) or by geological activity could be trapped in the resonant cavity formed by the surface and lower ionosphere of Mars, as it occurs on Earth giving rise to Schumann resonances. The finite difference time-domain technique (FDTD) is applied to model the atmosphere of Mars in order to determine Schumann resonant frequencies, and natural electromagnetic fields at the extremely low frequency range (ELF). A numerical tool is provided to analyze the electrical conductivity profile of the Martian atmosphere, with the aim of obtaining Schumann resonance frequencies and their dependenc…
Chemical composition of modern and fossil Hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 1: M…
2012
Bioapatite in mammalian teeth is readily preserved in continental sediments and represents a very important archive for reconstructions of environment and climate evolution. This project provides a comprehensive data base of major, minor and trace element and isotope tracers for tooth apatite using a variety of microanalytical techniques. The aim is to identify specific sedimentary environments and to improve our understanding on the interaction between internal metabolic processes during tooth formation and external nutritional control and secondary alteration effects. Here, we use the electron microprobe to determine the major and minor element contents of fossil and modern molar enamel, …
Geomaterials in green building practices: comparative characterization of commercially available clay-based plasters
2013
Three pre-mixed powdered clay-based (earthen) plasters produced in Europe and specifically designed for wall undercoating were analyzed in this paper. These materials are commercially available and successfully employed in green building practices all over the world. Their compositional and textural characteristics, as well as plastic behaviour were investigated through a multi-analytical approach: X-ray powder diffraction (XRPD), polarized light microscopy (PLM), X-ray fluorescence spectrometry (XRFS), scanning electron microscopy equipped with an energy dispersive spectrometer (SEM-EDS), mercury intrusion porosimetry (MIP), grain-size distribution (GSD) and semi-empirical tests (Atterberg…
Misura delle performance finanziarie e patrimoniali delle aziende agricole: proposta operativa per un nuovo modello di rating per le aziende agricole
2012
La profonda evoluzione dei sistemi agricoli negli ultimi anni hanno accresciuto l'attenzione di tutti gli attori istituzionali ed economici rispetto alla problematica dell'accesso al credito per le imprese. Nel passato molto spesso il credito in agricoltura ha usufruito di regimi "speciali"; con l'implementazione delle regole di Basilea 2 (più di recente Basilea 3), le condizioni per l'accesso al credito si sono notevolmente irrigidite. Nell'ambito del settore agricolo, la pressoché assenza di bilanci certificati rende particolarmente difficoltosa questa valutazione. Nel presente lavoro, dopo aver analizzato la letteratura in materia di valutazione del merito creditizio delle aziende agrico…
Wine label design as a strategic tool to attract consumers. A marketing study on Sicilian wine positioning
2013
Negli ultimi anni il packaging e stato considerato dalle aziende vinicole uno tra i piu importanti strumenti del marketing. Infatti, grazie all’utilizzazione di immagini e testi, e possibile comunicare chiaramente al mercato messaggi coerenti con i prodotti, con i valori dell’azienda e con i target di consumatori di riferimento. In questo studio si e voluto conoscere quanto le etichette siano importanti per le cantine siciliane nelle scelte di posizionamento dei loro vini. Si e voluta, inoltre, misurare l’influenza che le etichette esercitano sui consumatori, indirizzando ed orientando le preferenze al momento dell’acquisto di un vino, senza tralasciare l’eventuale effetto attrattivo causat…