131 research outputs found
THE VIRTUAL BATCAVE: A PROJECT FOR THE SAFEGUARD OF A UNESCO WHL FRAGILE ECOSYSTEM
Abstract. This abstract illustrates an interdisciplinary research project which focuses on the study, conservation and enhancement, through 3D digitization and virtual fruition, of an asset of great naturalistic, historical and ethnoanthropological value: Grotta dei Pipistrelli of Pantalica Nature Reserve (Sortino, SR). The cave (located in the Calcinara necropolis) is characterized by a great beauty as well as by a high cultural relevance and a remarkable scientific importance. In 2005, it awarded the UNESCO World Heritage title for its high historic, archaeological and speleological profile. Despite the site is being studied by specialists in chiropterofauna, nowadays there is not a comprehensive and reliable documentation of the plano-altimetric morphology of the cave, able to constitute a 3D database of essential information (e.g. morphological, geological, textural and wildlife information) for current and future studies, and to preserve the memory of this fragile ecosystem. The process of 3D digitization aims to create a model of the cave that allows us to enjoy this place, to explore it and to closely understand it in order to limit the anthropic pressure caused by visitors on the real site. Consequently, it is proposed the creation of a virtual environment, as a reproduction of the real one, which can be enjoyed by all categories of users.</p
Si and Sn doping of ε-Ga2O3 layers
Low resistivity n-type e-Ga2O3 epilayers were obtained for the first time either by adding silane to the gas phase during the metal organic vapour phase epitaxy deposition or by diffusing Sn in nominally undoped layers after the growth. The highest doping concentrations were few 1018 cm−3 and about 1017 cm−3 for Si and Sn doping, with corresponding resistivity below 1 and 10 Ω cm, respectively. Temperature dependent transport investigation in the range of 10-600 K shows a resistivity behavior consistent with the Mott law, suggesting that conduction through localized states dominates the electrical properties of Si- and Sn-doped samples. For both types of dopants, two different mechanisms of conduction through impurity band states seem to be present, each of them determining the transport behavior at the lower and higher temperatures of the measurement range.Low resistivity n-type e-Ga2O3 epilayers were obtained for the first time either by adding silane to the gas phase during the metal organic vapour phase epitaxy deposition or by diffusing Sn in nominally undoped layers after the growth. The highest doping concentrations were few 1018 cm−3 and about 1017 cm−3 for Si and Sn doping, with corresponding resistivity below 1 and 10 Ω cm, respectively. Temperature dependent transport investigation in the range of 10-600 K shows a resistivity behavior consistent with the Mott law, suggesting that conduction through localized states dominates the electrical properties of Si- and Sn-doped samples. For both types of dopants, two different mechanisms of conduction through impurity band states seem to be present, each of them determining the transport behavior at the lower and higher temperatures of the measurement range
Aluminium based components with enhanced characteristics through advanced squeeze casting process
Components in the field of automotive application produced by a modified squeeze casting process have beenconsidered. This innovative process has been oriented toward the manufacturing of high resistance and hightoughness automotive parts using A380 alloys and they have been subjected to T6 heat treatment. Standardsamples have been machined directly from real automotive components for tensile properties evaluation andhardness values determination. Superior mechanical characteristics have been obtained thanks to the lowporosity content and to the particular microstructure features. Fracture surfaces analysis have been realisedon the fractured samples, identifying some minor defects, like the presence of carbon particles (with anydangerous effect on the mechanical performances) and some nano-sized oxide inclusion. Moreover, the samefracture surface analysis highlights the ductile natures of the fracture. On the polished transverse sections ofthe samples morphological analysis has also been performed.High level of resistance and toughness has been obtained for all considered parts. The achieved resultsdemonstrate the reliability of the modified squeeze casting process for production of automotive components
Growth performance and quality traits of siberian sturgeon (A. baerii) juveniles fed diets including Nannochloropsis gaditana and Scenedesmus almeriensis microalgae meal
The demand for aquafeed grown exponentially in the last decade and is expected to increase further in the coming years (FAO 2018). The wild fish used for the fish meal and oil, currently used in feed formulated for carnivorous species, will be used in human consumption and less available for aquaculture. Among the potential ingredients of future use in aquafeed, microalgae represent a promising matrix, as characterized by nutritional, nutraceuticals and immunostimulant properties ( Camacho-Rodr\uedguez et al., 2017) . However the high production cost is a limiting factor for their use. The development of a microalgae-based biorefinery, able to use some by-products and agro-industrial waste to produce biomass would enable to limit the disposal costs sustained by the companies and to lower the production costs of the microalgae. The present research was undertaken to evaluate effect on growth response and fillet quality traits of sturgeon ( A. baerii) fed with two microalgae freeze-dried biomass Nannochloropsis gaditana and Scenedesmus almeriensis grown in Sinthetic Medium (SM) or in diluted Pig Manure (PM) and included in partial substitution of dietary fish meal and oil. Materials and methods Four complete diets were formulated to be grossly iso-proteic and iso-lipidic . A control diet (C ) was prepared using a blend of conventional animal and vegetal protein sources. The test diets coined respectively N. gaditana grown o n Synthetic Medium (NSM ), N. gaditana growno in pig manure (NPM), S. almeriensis grown on Synthetic Medium (SSM) and S. almeriensis grown on Pig Manure (SPM) were prepared by replacing the 10% of protein and lipid supplied by the blend of conventional protein and lipid-rich ingredients with microalgae . All the ingredients are mixed and pelleted by a cold extrusion process (70\ub0C). Each diet were randomly assigned to tank and tested in triplicate according to a monofactorial design. Microalgae dried biomass and diets were analized microbiologically and verified for nutritional quality. To carried out the feeding trials 240 j uvenile A. baerii ( average 12.8\ub10.3g each ) were randomly allocated among 15 circular tanks (16 fish/tank) in RAS system under controlled rearing conditions (temperature, 19\ub0C, DO 9.6 mg/L, artificial daylenght, 12h). Diets were offered in two daily meals with a fixed feed ratio (3 % body mass) over 6 weeks and each group were weighted every week under moderate anaesthesia. At the end of the trial, survival rate (%), Final Body Weight (FBW), Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Feed Intake (FI), were evaluated. Furthermore, nine fish per feed treatment were analized to determine the biometric indeces , fillet proximate composition and oxidation parameters (SOD, CAT, GPX, 8-isoprostanes). Data were subjected to ANOVA and differences tested by the Tukey's test (P < 0.05). Results The macronutrient composition of the dried micoalgae biomass are reported in Table I. Microbiological analysis of microalgae biomass showed no difference in TBC (Total Bacterial Count) among the different thesis (average 5.9\ub10. 07 log CFU/g). E. coli were found below the detection limits of the method (< 2 log CFU/g) in N. gaditana grown on P M and S. almeriensis grown in both SM and PM, while its value was 3log CFU/g in N.gaditana grown on SM. Enterobacteriaceae resulted respectively 2.7 and 2.0 log CFU/g in N. gaditana and S. almeriensis grown on SM and under detection limits of the method (< 2 log CFU/g) in N. gaditana and S. almeriensis grown on PM . Salmonella resulted absent in all the microagae biomass. All the diets used in feeding trial resulted similar for their proximate, fatty acid composition and microbiological quality (data not reported). Dietary treatments significantly affected FBW that resulted sim ilar in the groups C (44.2g), NSM (44.7g) e NPM (43.9g), while it was significantly lower (P<0.05) in the SSM (40.8g) and SPM (40.5g) groups. However, did not result in significant changes in survival rate, SGR, FCR and of the biometric index (K), nor fillet composition. Also oxidation parameters (SOD, CAT, GPX, 8-isoprostanes) of fillet were not significantly affected by dietary treatments (P>0.05). Discussion and Conclusion Very few data are available on the use of microalgae biomass in acipenserids diet . Spirulina meal integrated with plant oils was found to be a good alternative to replace fish oil in white ( A. transmontanus) and siberian ( A. baerii ) sturgeon diet (Palmegiano et al., 2008; 2002) . The data observed in this study confirm the potential use of the microalgae N. gaditana and S. almeriensis in the siberian sturgeon diet, in fact all the experimental diets tested, both based on microalgae grown o n SM and o n PM ensure a balanced and complete level of the nutrient s, suitable for the gr owth of sturgeon juveniles and nutritional quality of the fillet , analogous to the control group fed with a fish meal/oil-based diet . Moreover the use of agrozootenic by-products, such as pig manure, for the growth of microalgae, appears to be a good alternative to common fertilizers, to reduce production costs. Acknowledgments This work has received funding from the European Union HORIZON 2020 Research and Innovation Program under the Grant Agreement No. 727874 (project SABANA)
Influence of the nocturnal harvesting of olives from Salento (Italy) on the quality of the extra virgin olive oil
Identification of genomic regions associated with total and progressive sperm motility in Italian Holstein bulls
Sperm motility is directly related to the ability of sperm to move through the female reproductive tract to reach the ovum. Sperm motility is a complex trait that is influenced by environmental and genetic factors and is associated with male fertility, oocyte penetration rate, and reproductive success of cattle. In this study we carried out a GWAS in Italian Holstein bulls to identify candidate regions and genes associated with variations in progressive and total motility (PM and TM, respectively). After quality control, the final data set consisted of 5,960 records from 949 bulls having semen collected in 10 artificial insemination stations and genotyped at 412,737 SNPs (call rate >95%; minor allele frequency >5%). (Co)variance components were estimated using single trait mixed models, and associations between SNPs and phenotypes were assessed using a genomic BLUP approach. Ten windows that explained the greatest percentage of genetic variance were located on Bos taurus autosomes 1, 2, 4, 6, 7, 23, and 26 for TM and Bos taurus autosomes 1, 2, 4, 6, 8, 16, 23, and 26 for PM. A total of 150 genes for TM and 72 genes for PM were identified within these genomic regions. Gene Ontology enrichment analyses identified significant Gene Ontology terms involved with energy homeostasis, membrane functions, sperm-egg interactions, protection against oxidative stress, olfactory receptors, and immune system. There was significant enrichment of quantitative trait loci for fertility, calving ease, immune response, feed intake, and carcass weight within the candidate windows. These results contribute to understanding the architecture of the genetic control of sperm motility and may aid in the development of strategies to identify subfertile bulls and improve reproductive success
Flash Thermal Conditioning of Olive Pastes during the Olive Oil Mechanical Extraction Process: Impact on the Structural Modifications of Pastes and Oil Quality
Comparison of oxidation stability of virgin olive oils from different locations of Turkey
Chemical characterization and oxidative stability of olive oils extracted from olive trees of Southern Brazil
Phenolic extracts of coconut oil cake: a potential alternative for synthetic antioxidants
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