Search results for "Elements"
showing 10 items of 799 documents
From single fiber to macro-level mechanics: A structural finite-element model for elastomeric fibrous biomaterials
2014
In the present work, we demonstrate that the mesoscopic in-plane mechanical behavior of membrane elastomeric scaffolds can be simulated by replication of actual quantified fibrous geometries. Elastomeric electrospun polyurethane (ES-PEUU) scaffolds, with and without particulate inclusions, were utilized. Simulations were developed from experimentally-derived fiber network geometries, based on a range of scaffold isotropic and anisotropic behaviors. These were chosen to evaluate the effects on macro-mechanics based on measurable geometric parameters such as fiber intersections, connectivity, orientation, and diameter. Simulations were conducted with only the fiber material model parameters a…
Influence on self-efficacy of the degree of authenticity of the inquiry carried out in two secondary school science projects
2021
Las creencias sobre la propia capacidad para llevar a cabo con exito una tarea concreta (autoeficacia) influyen en la implicacion y la motivacion hacia dicha tarea. En las ultimas decadas se ha incrementado el foco de atencion hacia estas creencias en el area de ciencias no solo como uno de los predictores mas consistentes del desempeno real del alumnado, sino por la existencia de desigualdades sistematicas en la autoeficacia de chicos y chicas. Aunque el Aprendizaje Basado en Proyectos (ABP) en el aula de ciencias posee diversas caracteristicas que potencialmente pueden contribuir a la mejoria de la autoeficacia en ciencias del alumnado, las evidencias entre la relacion de los elementos de…
NONSTRUCTURAL SEISMIC PREVENTION AND REHABILITATION
2010
Il progetto di cooperazione internazionale finanziato nell’ambito del programma CoRI 2005/2006 dell’Ateneo di Palermo, ha visto coinvolte l’Università di Palermo e l’Università di Berkeley – USA, nella persona della Prof. Mary C. Comerio (Chair Department of Architecture). La prima fase del progetto è stata volta alla conoscenza dell’esperienza USA nella gestione degli edifici scolastici per potere riversare nella realtà italiana significativi apporti. La seconda fase del progetto ha previsto occasioni di confronto diretto con duplici finalità, sia di ricerca che di formazione didattica. Tra le varie attività previste nell’ambito di questa occasione, è stato organizzato un workshop in cui s…
ABO genotyping by PCR-RFLP and cloning and sequencing
2005
A refined PCR-RFLP based method was established to genotype ABO blood groups. The main objective of this study was to make the techniques also suitable for working with degraded DNA. Specific primer design was carried out to choose fragments shorter than 200 bp as necessary in forensic and archaeological applications. Four fragments of exon 6 and 7 of the ABO gene were amplified and digested by in total 7 restriction endonucleases. Particular attention was paid to the base changes at nucleotide positions 261(delG), 297, 526, 703, 721, 771, 796 and 1060(delC) in order to distinguish the six common alleles A101, A201, B, O01, O02 and O03. Furthermore, this method also enables determination of…
Settling Down: The Genome of Serratia symbiotica from the Aphid Cinara tujafilina Zooms in on the Process of Accommodation to a Cooperative Intracell…
2014
Particularly interesting cases of mutualistic endosymbioses come from the establishment of co-obligate associations of more than one species of endosymbiotic bacteria. Throughout symbiotic accommodation from a free-living bacterium, passing through a facultative stage and ending as an obligate intracellular one, the symbiont experiences massive genomic losses and phenotypic adjustments. Here, we scrutinized the changes in the coevolution of Serratia symbiotica and Buchnera aphidicola endosymbionts in aphids, paying particular attention to the transformations undergone by S. symbiotica to become an obligate endosymbiont. Although it is already known that S. symbiotica is facultative in Acyrt…
The Pattern of Rare Earth Elements Like a Possible Helpful Tool in Traceability and Geographical Characterization of the Soil-Olive System (Olea euro…
2022
The identification of a product, with its geographical origin, is a guaranty of the value of the foodstuff and protection from potential fraud. Extra virgin olive oil is produced or marketed as a single variety or a blend of two or more cultivars, often of different geographic origins. Therefore, to study a possible link between the soil and olive oil, we accounted crucial to analyse the behaviour of olive of different cultivars. We studied Rare Earth Elements (REE) amounts and their relationship to trace their distribution from soil to the olive pulp (Olea europea L.). The results obtained pointed out that the different cultivars of Olea did not drive significant differences in reciprocal …
Distribution of REEs in soil-citrus limon system(L.) Osbeck
2017
The consumers have an increasing interest about food traceability with respect to safety, quality and typicality issues. The knowledge of a chemistry relationship between the soil and the agricultural products is an important tool for the quality assessment of food. Citrus Limon is the most important fruit tree crop in the world and the detection of potential fraud could improve by using tools linking the chemistry composition of this production to its typical growing area. This study use rare earth elements (REEs) as geochemical tracers. The REEs are a set of 14 elements, from lanthanum to lutetium that can be divided in light rare earth elements (LREEs), from La to Gd and heavy rare earth…
Determination of Water-Soluble Trace Elements in the PM10 and PM2.5 of Palermo Town (Italy)
2022
This study contributes to the current knowledge on the solubility of trace elements in the atmospheric particulate matter of the urban area of Palermo. Daily sample filters of PM10 and PM2.5 were collected in monitoring stations within and outside the urban area, characterized by variable traffic density. The bulk of compositions in PM10 and PM2.5 were determined by ICP-MS. The water-soluble trace elements (WSTE) and major ion components of particulate matter were determined by ICP-MS and ion chromatography, respectively. A significant difference in the metals content was observed between the samples taken in urban areas and those from suburban areas. The calculated enrichment factor highli…
Beyond the mean: A comparison of trace- and macroelement correlation profiles of two lacustrine populations of the crayfish Procambarus clarkii
2018
In invertebrate biomonitors of chemical pollution, emphasis has been generally given to mean accumulation patterns and how they reflect varying environmental levels of contamination. Intra-population variability, and how it relates with individual phenotypic traits, has received less attention. Here, a set of analytes including trace elements (B, Ba, Cd, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sr, V, and Zn), macroelements (C, Ca, K, Mg, N, Na), and carbon and nitrogen stable isotopes (δ13C and δ15N) was measured in two populations of the crayfish Procambarus clarkii from Lake Trasimeno and Lake Bolsena (Central Italy). The influence of location, sex, body size, and condition factor was assessed; in ad…
Horizontal and vertical food web structure drives trace element trophic transfer in Terra Nova Bay, Antarctica
2019
Abstract Despite a vast amount of literature has focused on trace element (TE) contamination in Antarctica during the last decades, the assessment of the main pathways driving TE transfer to the biota is still an overlooked issue. This limits the ability to predict how variations in sea-ice dynamics and productivity due to climate change will affect TE allocation in the food web. Here, food web structure of Tethys Bay (Terra Nova Bay, Ross Sea, Antarctica) was first characterised by analysing carbon and nitrogen stable isotopes (δ13C, δ15N) in organic matter sources (sediment and planktonic, benthic and sympagic primary producers) and consumers (zooplankton, benthic invertebrates, fish and …