956 research outputs found
Non-orientable 3-manifolds of small complexity
We classify all closed non-orientable P2-irreducible 3-manifolds having
complexity up to 6 and we describe some having complexity 7. We show in
particular that there is no such manifold with complexity less than 6, and that
those having complexity 6 are precisely the 4 flat non-orientable ones and the
filling of the Gieseking manifold, which is of type Sol. The manifolds having
complexity 7 we describe are Seifert manifolds of type H2 x S1 and a manifold
of type Sol.Comment: 27 pages, 12 figures. Two mistakes contained in the previous version
are fixed: there is a Sol manifold with complexity 6, and the examples with
complexty 7 are Sol and H2xS1 (see the abstract
Natural zeolites and white wines from Campania region (Southern Italy): a new contribution for solving some oenological problems
The purpose of this research is to provide a new mixture of Campanian zeolitized tuffs for solving two specific problems in the production of white wines: the protein and tartaric stability. In fact, a very frequent cause of turbidity and formation of organic deposits in white wines is the occurrence of thermolabile and thermostable proteins colloidal suspensions which precipitate in time, especially in summertime and during the storage and transport. Normally, to mitigate this risk wine producers use organic and inorganic stabilizers and clarifiers. The best known treatment, recognized also by the International Organisation of Vine and Wine (OIV) foresees the use of bentonite with a montmorillonite content not lower than 80%. The present paper aims at evaluating the use of two high zeolite grade Italian volcanoclastites such as the Neapolitan Yellow Tuff (NYT) and the Yellow Facies of the Campanian Ignimbrite (YFCI), in the treatment of three peculiar white wines of the Campanian region (Southern Italy): Falanghina, Fiano di Avellino and Greco di Tufo. Granulates were produced starting from tuff blocks as provided by quarries. Some grain size fractions have been prepared to investigate the zeolite content (phillipsite + chabazite + analcime) by X-ray diffraction (XRD). A 2-5 mm grain size fraction was chosen for NYT and a 5-10 mm for YFCI. Three Campanian monocultivar white wines were used for the test: the Falanghina 2006 vintage, the Fiano di Avellino DOCG 2007 vintage, and the Greco di Tufo DOCG 2008 vintage. 48 samples with mixture of the zeolitized tuffs, 1 sample with mixture of a synthetic zeolite A and 1 sample with mixture of a commercial sodium activated bentonite were prepared. ICP-OES analysis for the determination of ECEC, Ion Chromatography (IC) analyses for the determination of some major cations and Turbidimetric tests for the definition of the protein stabilization process before and after treatments were also carried out. It was evidenced that high zeolitized tuff/wine ratios enable the protein stabilization whereas a significant decrease of potassium ion after the treatment with a zeolite-rich powder improves the tartaric stability, a serious problem in all the wine productions. The results of these tests refer to a laboratory scale research. A transfer of the experiment to a pilot plant scale is in progress
Using gravity models for the evaluation of new university site locations: a case study
A fundamental aspect of competitive spatial models is the choice behaviour of potential customers to patronize a facility. Most of
the models used to describe this phenomenon are essentially based on the adaptation of Newton’s law of gravitation to the economic case (gravity model).
This paper shows an application of this model to describe the behaviour of potential students in the choice of a university site. The results provided by the model have been compared with the actual data and show that the gravity model can describe the behaviour of potential students with good approximation
Models for the schedule optimization problem at a public transit terminal
This work deals with the proposal of some models for the schedule optimization problem for public transit networks. In particular, we consider the case of a transit terminal where passengers are supposed to split among different lines of a
service, or even change mode of transportation in case of intermodal systems. Starting from a given schedule for the transit lines arriving at the terminal, the aim is to decide
the optimal schedule for the output lines, in such a way to balance the operative costs of the service and the passenger waiting time at the transit terminal. We propose two
different models for this problem, which present strong similarities with some well known combinatorial optimization models. Computational results are also presented,
showing the suitability of the models to solve real case studies
The determinants of land use in Italy from a spatial perspective: A re-interpretation at the time of COVID-19
This work aims at providing a deeper understanding of the main determinants of land use in Italy by using a large dataset drawn from official sources for 2016 (ISTAT, ISPRA, SIEPI). The analysis is carried out at the municipal level (n= 7,798), corresponding to the NUTS-4/LUA level of the Eurostat classification, because in Italy each municipality is the main decision-maker of territorial planning strategies and tools. Moreover, as land use activities impact the environment with inevitable relationships between local agents, the analysis also investigates the effects of local neighbouring factors on land use decision-makers, as well as spatial interactions among local agents distributed in space
Exploring land use determinants in Italian municipalities: comparison of spatial econometric models
This study sets up a spatial econometric framework to explore the factors that best describe land consumption in Italy at the municipal level. By modelling the different types of spatial interactions and geographical proximity between all Italian municipalities, the direct effects of land use drivers are assessed together with spillover effects. Land use data are drawn from the ISPRA-SNPA 82/18 Report and cover all 7,998 Italian municipalities. The results highlight the existence of endogenous and exogenous interaction effects and the crucial role of the demographic, socio-economic and institutional structure on land use intensity. Hence the need for a planning policy aimed at: i) strengthening institutional cooperation to deal with excessive administrative fragmentation; ii) improving institutional and governmental quality to trigger virtuous mechanisms for sustainable land use management
Tailored treatment of intestinal angiodysplasia in elderly
Background: Angiodysplasia of the gastrointestinal tract is an uncommon, but not rare, cause of bleeding and severe anemia in elderly. Different treatments exist for this kind of pathology. Methods: The aim of this work was to study 40 patients treated for intestinal angiodysplasia with two different kind of endoscopic treatments: argon plasma coagulation (APC) and bipolar electrocoagulation (BEC). Results: Age of patients was similar in both groups (76,2 ± 10.8 years vs 74,8 ± 8,7 years, P = 0,005). Angiodysplasia treated were located in small bowel, right colon, left colon, transverse colon and cecum. We analysed number of treatment, recurrence, hospital discharge, needs of blood transfusions before and after endoscopic treatment. Number of treatment was the same in both groups (1,2 ± 0,2 vs 1,1 ± 0,1, P < 0,001). We had more recurrence in patients treated with BEC (4/20 vs 2/20, P < 0,001). Hospital discharge was comparable in both groups (5,3 ± 3,1 days vs 5,4 ± 2,8 years, P < 0.001) Conclusions: Treatment of angiodysplasia in elderly is not easy. Different kinds of treatment could be adopted. APC and BEC are both safe and effective. The choice of a treatment should consider several factors: age, comorbidity, source of bleeding. In conclusion we think that treatment of bleeding for angiodysplasia in elder population should be a tailored treatment. © 2015 Rita Compagna et al., published by De Gruyter Open
A Privacy-Oriented Approach for Depression Signs Detection Based on Speech Analysis
Currently, AI-based assistive technologies, particularly those involving sensitive data, such as systems for detecting mental illness and emotional disorders, are full of confidentiality, integrity, and security compromises. In the aforesaid context, this work proposes an algorithm for detecting depressive states based on only three never utilized speech markers. This reduced number of markers offers a valuable protection of personal (sensitive) data by not allowing for the retrieval of the speaker's identity. The proposed speech markers are derived from the analysis of pitch variations measured in speech data obtained through a tale reading task performed by typical and depressed subjects. A sample of 22 subjects (11 depressed and 11 healthy, according to both psychiatric diagnosis and BDI classification) were involved. The reading wave files were listened to and split into a sequence of intervals, each lasting two seconds. For each subject's reading and each reading interval, the average pitch, the pitch variation (T), the average pitch variation (A), and the inversion percentage (also called the oscillation percentage O) were automatically computed. The values of the triplet (Ti, Ai, Oi) for the i-th subject provide, all together, a 100% correct discrimination between the speech produced by typical and depressed individuals, while requiring a very low computational cost and offering a valuable protection of personal data
MECHANIZED HARVESTING TESTS PERFORMED BY GRAPE HARVESTERS IN SUPER INTENSIVE OLIVE ORCHARD CULTIVATION IN SPAIN
Today also those countries boasting a century-old olive growing tradition have to look at the latest, most dynamic, non labour-intensive olive growing systems to abate production (notably, harvesting operations) costs and remain competitive in a globalized market. This is why over the last few years super intensive olive orchard cultivation has been attracting a lot of interest on the part of olive growers all over the world as it accounts for an innovative model whereby olive groves are tailored to the special needs of grape harvesters. This paper reports the first results of experimental mechanical harvesting tests in a super-intensive olive cultivation. The study is intended to explore both productivity and work capacity of two of the most commonly used grape harvesters, Grégoire G120SW and New Holland Braud VX680, in a view to assessing their harvesting performance by a series of tests conducted in Spain. On the basis of the tests it was possible to verify that the machines are able to detach the almost all the drupes (more than 90%), with one only passage, and this independently of both size and location of drupes on the tree crown and of their maturity stage. Using these machines, two people can often carry out the whole harvest process: an operator driving the harvester and another person transferring the fruit from the harvester in the field to the olive oil mill for processing. With this system, the work speed is usually, in the best working conditions, about 1.7 km/hour and the average harvesting time is about 2.5-3 hours/ha. For the time being it is however impossible to draw definitive conclusions in terms of performance of the above cultivation systems and harvesting machines. Additional key observational studies are needed in the years to come to assess the efficiency of the entire model
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