3,693 research outputs found
Environmental improvement and conservation of useful pastures for wild herbivores in a Regional Park on the Apennines mountains
In order to investigate some effects of the environmental management with faunistic purpose on pastures located on the Apennines mountains, in open areas subjected to bracken fern (Pteridium aqulinum) infestation, samples of vegetation were taken for three years on an open area in the Regional Park of "Laghi di Suviana e Brasimone" (BO). Experimental samples, taken before and after the agronomical works, showed the effects of the pasture improvement on botanical composition, richness and biodiversity. The agronomical pasture management produced a considerable decrease in bracken density and an increase on biodiversity, and the final average value of the Pastoral Value index was quadruplicate. These results confirmed the effectiveness of the actions carried out and the importance of maintaining a continuous programme of pasture management through annual clearing of vegetation
Improvement of self-sufficiency for an innovative nearly zero energy building by photovoltaic generators
In the present work, a case study of an innovative nearly Zero Energy Building (nZEB) for academic purposes is investigated. In particular, its primary energy vector is electrical, i.e. a Photovoltaic (PV) generator is coupled with storage units and supplies the electrical loads and the thermal demand, which is converted into electrical by heat pumps. The system is designed to maximize the self-sufficiency and minimize the absorption from the grid. Moreover, the nZEB is equipped with sensors that are oriented to smart metering in order to monitor the energy exchange between the rooms of the building. An energy simulation is performed on a yearly basis, evaluating the size of the batteries, to reach the optimal compromise between benefits, in terms of self-sufficiency, and costs
Feeding evaluation of spontaneous species used by wild ungulates
Abandonment of traditional agricultural practices can produce remarkable effects on land use and on the vegetal composition of marginal areas. This is particularly true in the once grazed zones in the mountain environments, that are now affected by encroachment of shrubby vegetation. The conservation of these open areas and the preservation of a correct ratio pasture/wood are of extremely importance for wild animals. In this note we describe the effectiveness of agronomical intervention carried out to enhance pasture quality in a protected area of central Italy. Data collection concerned botanical composition, floristic richness and biodiversity of vegetation, before and after the intervention efforts. Moreover, data on utilization of single species were collected in order to evaluate the real consumption of each plant species by wild animals. Results confirmed the efficiency of the improvement of the studied area in terms of botanical composition and of pastoral value and they provided useful indications about the actual utilization of non forage plants by wild ungulates
Innovative teaching on photovoltaic generation
One of the most important technologies for the renewable energy production is the Photovoltaic (PV) one. In the last decades, the enormous growth in the world of Photovoltaic installation capacity, and future trends, makes the knowledge of this topic fundamental for engineers working in the energy field with this competence, and not only. Thus, for students enrolled in industrial engineering courses, appropriate and innovative teaching methods are necessary. This paper aims to describe the structure of the course 'Photovoltaic Power Generation' in which solar resource and the photovoltaic generators, including power electronics, are explained. The topics of traditional theoretical lectures are presented, with the links to practical exercises and laboratories
Comparison of correction methods of wind speed for performance evaluation of wind turbines
The performance of horizontal axis wind turbines strongly depends on the speed of the wind that enters in the rotor of the turbine. Unfortunately, this quantity is rarely available since the wind speed is measured on the back of the turbine, where a lower value is present. For this reason, two correction methods are usually employed that require two input quantities: the wind speed on the back of the turbine nacelle and the wind speed detected by a meteorological station close to the investigated turbine. Since an anemometric station is not always available, a third method is here proposed that does not require this input quantity. The proposed method relies on the wind speed on the back of the turbine and the manufacturer power curve. The effectiveness of such a method is shown by comparison to the results obtained with the standard methods implemented on a wind power plant in Southern Italy
Experimental testing of a horizontal-axis wind turbine to assess its performance
This paper describes a test procedure to investigate the performance of a micro wind turbine with horizontal-axis. A 3D model of a rotor with five blades has been designed by a MATLAB software; its airfoil is optimized to efficiently work at low wind speed. The rotor is coupled to an electric generator and this equipment is tested in a wind tunnel. An anemometer is used to measure and set the desired wind speeds. Electric quantities, i.e., voltage, current and power, are acquired by a digital multimeter. A variable resistance is used to change the operating point of the generator. Preliminary results are reported that refer to the application of the proposed test procedures to a wind turbine with a 0.2 m2 swept area
The cost of inflammatory bowel disease management matches with clinical course: A single outpatient centre analysis
Inflammatory bowel diseases (IBD) have a large economic burden on health systems. Our single-centre observational retrospective study aimed to assess an economic evaluation in two IBD outpatient cohorts (biological and conventional therapy) in relation to disease activity within a three-year follow-up. Four hundred and seventeen consecutive IBD patients referred to our tertiary gastroenterology unit (Bari-Puglia-Southern Italy) on January 2014–December 2016 were included. For each group (conventional/biological), we assessed direct/indirect costs and clinical/endoscopic activity within the first year and along the three-year follow-up. Statistical analyses: Wilcoxon signed-rank test (continuous variables), chi-square and Fisher’s test (categorical variables), Spearman ranks (single outcome) and ANOVA (detection time, clinical/endoscopic scores) were used. Continuous variables were expressed as mean ± standard deviation and range and/or median, interquartile range and range; categorical variables were expressed as proportions with 95% confidence interval. Direct and indirect cost items of 2014 and 2014–2016 were higher in patients treated with biological than conventional therapy. Subjects on biological therapy were younger and showed clinical and endoscopic moderate-to-severe disease activity. After three years, they reached a significant improvement from baseline. Conversely, disease activity was mild when conventional treatment had a beneficial effect. In conclusion, overall IBD management cost matches with clinical course and needs long-term evaluation in critical patients
Innovative Laboratories for Teaching on Photovoltaic Generation in Higher Education
The production of energy from Photovoltaic technology is becoming more and more relevant. Therefore, it is essential that academic world focuses attention on this topic in order to properly teach and transmit knowledge, skills and abilities. These ones are very useful in work activities. The academic course 'Photovoltaic Power Generation' aims to better explain theoretical aspects by practical activities which require the implementation of innovative laboratories for learning. This paper presents the guidelines for replication of laboratory practices (twin labs), already offered to Italian students, in the context of the project EU-MONG
The new TNM classification of lymph node metastasis minimises stage migration problems in gastric cancer patients
The present study aimed at investigating whether in gastric cancer patients stage migration occurs with extension of lymphadenectomy, when node metastases are staged according to the new pN classification (UICC 1997). The investigation involved 921 patients, who underwent R0 gastric resection for gastric cancer between 1988 and 1998 in three different Italian centres: Verona (n=236), Forlì (n=409), Siena (n=276). The relation among lymphadenectomy and pN category was assessed by Kendall's partial rank-order correlation coefficient, controlling for depth of tumour invasion. A direct evaluation of the Will Rogers phenomenon was accomplished in the Verona series, by comparing the number of positive nodes actually observed with the number of positive nodes which would have been retrieved by a less extended lymphadenectomy (D1). The number of positive nodes increased remarkably with the enlargement of lymphadenectomy, especially in pT2 patients (from 2.2±3.9 in D1 to 3.9±5.0 in D3) and in pT3/pT4 patients (from 5.1±5.9 in D1 to 11.3±12.6 in D3). Non-parametric statistics highlighted a weak (Kendall's partial T=0.128) but significant (P<0.001) correlation between pN category and extension of lymphadenectomy. In the direct analysis of the Verona series, 22 patients out of 230 (9.6%) migrated to a lower pN tier when ignoring positive nodes retrieved from the second and third level. This percentage increased to 39.1% (90 out of 230) when adopting the TNM 87 classification. In conclusion stage migration is of minor importance in gastric cancer patients, staged according to the new pN classification
Therapeutic sequences in patients with grade 1−2 neuroendocrine tumors (NET): an observational multicenter study from the ELIOS group
Purpose: Many different treatments are suggested by guidelines to treat grade 1−2 (G1−G2) neuroendocrine tumors (NET). However, a precise therapeutic algorithm has not yet been established. This study aims at identifying and comparing the main therapeutic sequences in G1−G2 NET. Methods: A retrospective observational Italian multicenter study was designed to collect data on therapeutic sequences in NET. Median progression-free survival (PFS) was compared between therapeutic sequences, as well as the number and grade of side effects and the rate of dose reduction/treatment discontinuation. Results: Among 1182 patients with neuroendocrine neoplasia included in the ELIOS database, 131 G1–G2 gastroenteropancreatic, lung and unknown primary NET, unresectable or persistent/relapsing after surgery, treated with ≥2 systemic treatments, were included. Four main therapeutic sequences were identified in 99 patients: (A) somatostatin analogs (SSA) standard dose to SSA high dose (n = 36), (B) SSA to everolimus (n = 31), (C) SSA to chemotherapy (n = 17), (D) SSA to peptide receptor radionuclide therapy (PRRT) (n = 15). Median PFS of the second-line treatment was not reached in sequence A, 33 months in sequence B, 20 months in sequence C, 30 months in sequence D (p = 0.16). Both total number and severity of side effects were significantly higher in sequences B and C than A and D (p = 0.04), as well as the rate of dose reduction/discontinuation (p = 0.03). Conclusions: SSA followed by SSA high dose, everolimus, chemotherapy or PRRT represent the main therapeutic sequences in G1−G2 NET. Median PFS was not significantly different between sequences. However, the sequences with SSA high dose or PRRT seem to be better tolerated than sequences with everolimus or chemotherapy
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