Search results for "engineering.material"
showing 10 items of 2352 documents
STUDIO PROPEDEUTICO PER LA REDAZIONE DI UN PIANO DI GESTIONE FORESTALE DEL BOSCO TARDARA, SUGHERETA PURA DEL COMUNE DI TUSA (MESSINA)
2019
La Sicilia è la seconda regione d’Italia per estensione delle formazioni naturali a Quercus suber (L.).Sugherete più o meno degradate sono presenti in tutte le province, il cui stato qualitativo oggi risulta carente a causa dei frequenti incendi, pascolo eccessivo e mancanza di adeguate cure colturali, ma certamente tra tutte le cause la principale è l’assenza di pianificazione. Da questa premessa affiora la necessità di conoscere e governare in modo congruo la superficie boscata siciliana attraverso la redazione di Piani di Gestione Forestale, mirando al ripristino dell’efficienza, della funzionalità e, in particolar modo, della produzione sostenibile dei boschi a sughera. Con il presente …
Effects of endogeic earthworms on soil processes and plant growth in coniferous forest soil
1992
The effects of the endogeic earthworm, Aporrectodea caliginosa tuberculata (Eisen) on decomposition processes in moist coniferous forest soil were studied in the laboratory. The pH preference of this species and its effects on microbial activity, N and P mineralization, and the growth of birch seedlings were determined in separate pot experiments. Homogenized humus from a spruce stand was shown to be too acid for A. c. tuberculata. After liming, the earthworms thrived in the humus and their biomass increased (at pH above 4.8). In later experiments in which the humus was limed, the earthworms positively influenced the biological activity in humus and also increased the rate of N mineralizati…
Site quality evaluation by classification tree: an application to cork quality in Sardinia
2005
Cork harvesting and stopper production represent a major forest industry in Sardinia (Italy). The target of the present investigation was to evaluate the ‘‘classification tree’’ as a tool to discover possible relationships between microsite characteristics and cork quality. Seven main cork oak (Quercus suber) producing areas have been identified in Sardinia, for a total of more than 122,000 ha. Sixty-three sample trees, distributed among different geographical locations and microsite conditions, were selected. A soil profile near each sample tree was described, soil samples were collected and analysed. After debarking, cork quality of each sample tree was graded by an independent panel of e…
Grape pulp, grape pips and their mixture: Novel substrates or supports for solid state fermentation
1997
Grape marc, comprising of grape pulp and grape pips, is generated in high quantities during ethanol production, but has no significant commercial value. The components of the grape marc, individually or in combination, can serve as substrate or support in solid state fermentation. The potential benefits of sieved fractions (800-3150 µm particle size) was, therefore, evaluated using Trichoderma viride, with or whithout enrichment. Based on sorption isotherm profiles, grape pulp showed the best performance, though its ability to promote biomass formation was the lowest. The latter could be improved by enrichment with glucose. It, thus, offers potential as a reusable support. Grape pips promot…
Incidence of heavy metals in the application of inorganic fertilizers to rice farming soils (Valencia, Spain)
1996
The presence of Cd, Co, Cu, Ni, Pb, Zn, Fe and Mn in different inorganic fertilizers (urea, calcium superphosphate, iron sulphate and copper sulphate) are evaluated and the contribution of these metals to the soils in this way is estimated. The studied zone corresponds to rice farming and is at the north of Albufera Natural Park (Valencia, Spain). The results obtained show that Superphosphate is the fertilizer that contains the highest levels of Cd, Co, Cu and Zn as impurities. Copper sulphate and iron sulphate have the most significant contents of Pb, and are the only fertilizers in which Ni is detected. The most significant additions of impurities that the soil received by agricultural pr…
Tarbellastraea (Scleractinia): A new stable isotope archive for Late Miocene paleoenvironments in the Mediterranean
2008
Abstract Geochemical proxy records of sea surface temperature (SST) or sea surface salinity (SSS) variability on intra- and interannual time-scales in corals from geological periods older than Pleistocene are extremely rare due to pervasive diagenetic alteration of coralline aragonite. Very recently, however, stable isotope data (δ18O, δ13C) from specimens of Porites of Late Miocene age (10 Ma) have been shown to preserve original environmental signatures. In this paper we describe new finds of the zooxanthellate corals Porites and Tarbellastraea in exceptional aragonite preservation from the island of Crete in sediments of Tortonian (∼ 9 Ma) and Early Messinian (∼ 7 Ma) age. Systematic, co…
Bryophyte diversity in the gypsum outcrops of Sicily (Italy)
2020
Abstract: A study on the bryophyte diversity of 12 Sicilian gypsum outcrops, falling in 4 Nature Reserves and 5 Special Areas of Conservation (SAC), is presented in order to increase knowledge about this peculiar flora for which conservation efforts need to be addressed. The bryoflora consists of a total of 85 taxa, 8 liverworts and 77 mosses, most of them belonging to the Pottiaceae family and characterized by xero-morphological adaptations. The bio-ecological analysis has emphasized the prevalence of xerophytic and basiphytic species with life form turf and life strategy colonist. Regarding the gypsicolous character, only one species, Tortula revolvens, behaves as a strict gypso- phyte, a…
Impact Assessment of Skidding Extraction: Effects on Physical and Chemical Properties of Forest Soils and on Maple Seedling Growing along the Skid Tr…
2019
Several studies investigated soil disturbances caused on skid trails by forest logging. However, there is still a lack of knowledge about the severity and the distance of disturbances along both sides from the trails. The aims of this study were: i) to investigate the changes in physical and chemical properties of soil along the sides of skidding trails
Recognition of Chip Forms by Means of Dynamic Force Spectrum Analysis
1993
In this study the ability to identify chip forms occurrs in the turning of austenitic stainless steel using dynamic force spectrum analysis has been tested. For this purpose the frequency spectra obtained from various metal cutting tests were recorded along with the static cutting forces. A dual channel analysis, based on the Fast Fourier Transform (FFT), was adopted to help identify the continuous/discontinuous (favourable/unfavourable) chip forming boundary. The results showed an acceptable correlation between the types of the frequency spectra and the types of chip forms. Finally, an original classification of the spectra obtained during turning of AISI 304 (DIN 1.4301) stainless steel i…
Environmental performance of building materials: life cycle assessment of a typical Sicilian marble
2009
Background, aim, and scope: The building sector is strategically important for achieving sustainability. Therefore, the improvement of energy and environmental performances are relevant targets because precious building materials such as marble have a significant impact on the environment. The aim of this paper is an analysis of a typical Sicilian marble (Perlato di Sicilia) to evaluate its energy and environmental performance. Marble plays an important role in the economy of Italy and has a global market share of 58% in terms of exports. For the main production areas of marble, relevant environmental performance data are missing except for one region (Tuscany-Massa e Carrara province). Per…