Search results for " pellets"
showing 7 items of 7 documents
The owl that never left! Taphonomy of Earlier Stone Age small mammal assemblages from Wonderwerk Cave (South Africa)
2022
Wonderwerk Cave, in South Africa, is an exceptional site that has yielded a large collection of small mammal fossils in a stratigraphic sequence reaching back ca. 2 million years. Taphonomic studies undertaken to date, show that Tytonidae (likely Tyto alba) was the dominant predator during the Earlier Stone Age. They produced masses of pellets that formed a dense carpet-like surface that covered the cave floor at intervals throughout the sequence. This paper compares the taphonomic signatures of five different Earlier Stone Age small mammal assemblages from Wonderwerk Cave, including assemblages not studied before, as well as a modern pellet assemblage collected from inside the cave. These …
A taphonomic investigation of small vertebrate accumulations produced by the snowy owl (Bubo scandiacus) and its implications for fossil studies
2019
17 pages; International audience; The action of predators, such as diurnal raptors, owls, mammals or humans, influence the nature of smallvertebrate fossil assemblages but currently their taphonomic features are still poorly understood. In this study,we investigate the taphonomic signature of the snowy owl (Bubo scandiacus) based on an analysis of pelletscollected at breeding sites located in Greenland and the Canadian Arctic. This taxon is widely distributedthrough the North Hemisphere and was an important predator in Pleistocene times. Taphonomic parameterssuggest that, contrary to previous assumptions, B. scandiacus produces, on average, moderate digestion of incisors,molars and post-cra…
A comparative economic analysis of torrefied pellet production based on state-of-the-art pellets
2017
Abstract Torrefied pellets have fuel properties superior to those of conventional wood pellets and potentially allow greater rates of co-firing and thus larger reductions in net CO 2 emissions. Despite the growing amount of scientific output on torrefaction, the economic feasibility of torrefied pellet production is still a topic of considerable uncertainty. This is an obstacle for decision makers looking to implement sustainable energy policies. This paper compares the economics of torrefied pellets to conventional wood pellets. Working backwards from demonstrated pellet properties, this work attempts to answer the following question: Based on state-of-the-art torrefied pellets, what would…
Characterization of phenolic solid state pellets for ESR dosimetry with radio-therapeutic photon and electron beams
2018
Introduction Among the various dosimetric techniques used for characterizing the radiation beams used in radiation therapy, the electron spin resonance (ESR) arouses increasing interest for applications in various therapy procedures. In this work we report the ESR investigation of particular phenol compound (IRGANOX 1076) exposed to clinical photon and electron beams (Gallo et al., 2017). Methods Phenol (IRGANOX 1076 - Sigma Aldrich) pellets were produced also with paraffin (10% by weight). Phenol pellets were exposed to clinical photon and electron beams at various energies produced by a linear accelerator (LINAC) Siemens Primus (Siemens Medical Systems, CA, USA) installed at the Radiother…
Torrefied versus conventional pellet production – A comparative study on energy and emission balance based on pilot-plant data and EU sustainability …
2015
Abstract Torrefaction is an emerging technology which enables greater co-firing rates of biomass with coal. To date however there has been a lack of real production data from pilot-scale torrefaction plants. Without such data any environmental benefits of torrefied pellet production are difficult to quantify. In this study data on consumable inputs from a semi-industrial torrefaction plant and the physical properties of produced pellets are used to analyse energy input and air emissions of torrefied pellet production and product transport. EU sustainability criteria are used to compare CO2-equivalent emissions from torrefied and conventional pellet production starting from harvesting of log…
Evidence suggests an opportunistic entomophagous diet of the White Stork Ciconia ciconia in Sicily during breeding and post-breeding periods
2022
Insects are known to represent a critical part of the White Stork Ciconia ciconia diet throughout its breeding range. Yet, the composition of the diet in the storks breeding in the Mediterranean regions remains poorly explored. Here, we investigated the diet of a population of white storks from Sicily through pellets collected in 2003, 2007, and 2020. A total of 1,928 prey items were identified and classified into six categories. Insects dominated the diet in all years and represented 99.06% of the whole prey number. Two orders of insects were mainly consumed, namely Orthoptera, which were the most frequent prey, followed by Coleoptera. Within these, carabid beetles were dominant, followed …
The Effect of Electric Field Configuration on the Thermo-Chemical Conversion of Straw Pellets
2020
Abstract With the aim to control and improve the thermo-chemical conversion of straw pellets, the experimental investigations of the DC electric field effect on the combustion dynamics and heat energy production were made. The electric field effect on the gasification/combustion characteristics was studied using three different positions of the positively charged electrode in flame. First, the electrode was positioned coaxially downstream the flame flow. Next, the electrode was positioned coaxially upstream the flame flow and, finally, the electrode was positioned across the downstream flow. The bias voltage of the electrode varied in the range from 0.6 up to 1.8 kV, while the ion current i…