Search results for "component"

Chemometric investigation on structural changes in pine kraft lignin during pulping

2000

Abstract Various structural changes which take place in dissolved lignin during the laboratory-scale kraft pulping of Scots pine (Pinus sylvestris) were studied. Lignin samples were subjected to the alkaline cupric oxide oxidation and the analytical data further processed by various multivariate chemometric techniques (principal component analysis, PCA; principal component regression, PCR; and projection to latent structures, PLS). Several models applicable to the indirect measurement of common pine kraft pulp properties (i.e., total cooking yield, kappa number and ISO brightness) were produced.

Regional frequency analysis of extreme rainfall in Sicily (Italy)

2018

Extreme rainfall events have large impacts on society and are likely to increase in intensity under climate change. For design and management decisions, particularly regarding hydraulic works, accurate estimates of precipitation magnitudes are needed at different durations. In this article, an objective approach of the regional frequency analysis (RFA) has been applied to precipitation data for the island of Sicily, Italy. Annual maximum series for rainfall with durations of 1, 3, 6, 12, and 24 h from about 130 rain gauges were used. The RFA has been implemented using principal component analysis (PCA) followed by a clustering analysis, through the k-means algorithm, to identify statistical…

LE COMPONENTI TERRITORIALI DELLO SVILUPPO RURALE: IL CASO STUDIO CALATINO.

2012

Biodiversità in alcune specie del genere Mentha nel territorio dei Monti Nebrodi (Sicilia N-W).

2008

In Nebrodi Mountains (N-E Sicily), the genus Mentha is represented by an high number of species, in many cases typical of humid and subhumid environments. This work was addressed to investigate about the biomorphological traits of various accessions belonging to 3 Mentha species collected in the Nebrodi highlands, namely 22 accessions of Mentha spicata, 12 of Mentha suaveolens and 13 of Mentha aquatica. Plant material was picked up starting from the early spring 2007, from different sites as in altitude and in pedological and climatic traits, that were distributed over an area of 200.000 ha approx.. Later on, all collected plant individuals were transplanted in a collection field, appositel…

Activity against microorganisms affecting cellulosic objects of volatile constituents of Leonotis nepetaefolia from Nicaragua

2014

The chemical composition of the essential oil from aerial parts of L. nepetaefolia (L.) R. Br. collected in Nicaragua was evaluated by GC and GC-MS. The main components were (Z)-phytol (22.8%), caryophyllene oxide (18.9%) and hexahydrofarnesylacetone (9.0%). The antibacterial activity against several Gram + and Gram-bacteria, including Bacillus cereus and B. subtilis, both infesting historical cellulosic material, was also determined. B. cereus, B. subtilis and Staphylococcus epidermis were the most affected by the action of the oil.

Modelling of Systems with a Dispersed Phase: “Measuring” Small Sets in the Presence of Elliptic Operators

2016

When modelling systems with a dispersed phase involving elliptic operators, as is the case of the Stokes or Navier-Stokes problem or the heat equation in a bounded domain, the geometrical structure of the space occupied by the dispersed phase enters in the homogenization process through its capacity, a quantity which can be used to define the equivalence classes in \(H^1\). We shall review the relationship between capacity and homogenization terms in the limit when the number of inclusions becomes large, focusing in particular on the situation where the distribution of inclusions is not necessarily too regular (i.e. it is not periodic).

Robotic total knee arthroplastyThe accuracy of CT-based component placement

2004

Accurate alignment of the components in total knee arthroplasty is important. By use of postoperative CT controls, we studied the ability of a robotic effector to accurately place and align total knee arthroplasty (TKA) components according to a purely CT-based preoperative plan.Robotic TKA was performed in 13 patients (6 men) with primary gonarthrosis. Locator screws were placed into femur and tibia under spinal anesthesia. A CT-scan including the femoral head, knee and ankle was performed. In the preoperative planning software, virtual components were positioned into the CT volume. In a second operation, the robot milled femur and tibia with a high-speed milling tool according to the preo…

Molecular characterization of Sicilian lentil ecotypes using ISSR.

2013

Macrolepidoptera (Insecta: Lepidoptera) Indicator of Climate Changes

2011

Lately, it has become increasingly clear that global warming has a significant impact on a broad range of organisms, regardless of their ecological and geographical spread. Temperature is one of the most important abiotic factors that determine the spatiotemporal dynamics of structural and functional parameters of populations of Lepidoptera and influencing production and survival of these species of insects in nature. Climate warming has the potential to affect some processes related to the ecology and life cycle of the butterfly, especially directly controlled temperature, such as: gathering the required temperature for a species to reach reproductive maturity, growth initiation and cessat…

Classification of Spanish Mosquitoes in Functional Groups

2011

Abstract We present a classification of Spanish mosquitoes according to their different life cycles. The bio-ecological parameters analyzed in our study were oviposition sites, overwintering stages, preferred hosts, and number of generations per year for each species. The results revealed 13 different functional groups. To assess the validity and robustness of the classification system, we analyzed the data from an intensive sampling carried out over a period of 4 years (2005–08) in eastern Spain. In this area, 9 of the 13 functional groups were found. The Jaccard cluster and the principal components analysis (between-group analysis method) revealed 3 different mosquito groups: the tree hol…