Search results for "forest"
showing 10 items of 3780 documents
A machine learning application to predict early lung involvement in scleroderma: A feasibility evaluation
2021
Introduction: Systemic sclerosis (SSc) is a systemic immune-mediated disease, featuring fibrosis of the skin and organs, and has the greatest mortality among rheumatic diseases. The nervous system involvement has recently been demonstrated, although actual lung involvement is considered the leading cause of death in SSc and, therefore, should be diagnosed early. Pulmonary function tests are not sensitive enough to be used for screening purposes, thus they should be flanked by other clinical examinations
Optimising the efficiency of olive harvesting considering operator safety
2019
Mechanical-assisted harvesting of olives, which is carried out using hand-held harvesting units that detach the drupes through vibration supplied by electric motor or combustion engines, is a widespread method used in southern Italy. Such machines are able to harvest more than 80% of the overall quantity of olives available per tree in 5–10 min, but their performance is influenced by several factors related to the mechanical characteristics of the device and to the features of the trees. Here the problem of optimising harvesting efficiency whilst minimising the health risks to the operators is investigated, with the aim of demonstrating that it is possible to determine an optimum harvesting…
A numerical study of the Schumann resonances in Mars with the FDTD method
2007
[1] Natural electromagnetic waves generated near the surface by electrostatic discharges in dust storms (dust devils) or by geological activity could be trapped in the resonant cavity formed by the surface and lower ionosphere of Mars, as it occurs on Earth giving rise to Schumann resonances. The finite difference time-domain technique (FDTD) is applied to model the atmosphere of Mars in order to determine Schumann resonant frequencies, and natural electromagnetic fields at the extremely low frequency range (ELF). A numerical tool is provided to analyze the electrical conductivity profile of the Martian atmosphere, with the aim of obtaining Schumann resonance frequencies and their dependenc…
Application of GPS tracking for monitoring spatially unconstrained outdoor recreational activities in protected areas – A case study of ski touring i…
2018
Abstract New trends in leisure and outdoor recreation show an increased penetration of remote areas and the development of spatially unconstrained outdoor recreational activities. Here we present the application of GPS tracking to monitor a spatially unconstrained recreational activity, using ski touring in the Tatra National Park (TNP) as a study case. Particular focus of the study was the spatial and temporal behaviour of ski tourers with regard to existing management measures implemented in the Park, where recreation is limited to designated zones. The research is based upon empirical data (n = 427 ski touring GPS tracks). ArcGIS and statistics software SPSS were used for spatial and sta…
Short-duration rainfalls in Sicily
1990
The Italian Hydrographic Service publishes yearly maximum rainfall depths with 1-, 3-, 6-, 12-, and 24-hr duration, recorded by recording rain gauges. It also publishes selected short-duration (t<1 hr) rainfall amounts. It is impossible to carry out a statistical analysis of the short-duration rainfalls for each recording rain gauge because the published data correspond to different record durations and to different recording rain gauges from year to year. Therefore, there is a practical need to derive empirical relationships between the 1-, 3-, 6-, 12-, and 24-hr duration amounts and shorter duration (t<1 hr) rainfall amounts. Such a relationship has been proposed by Bell and has been veri…
Efficacy of lumen-apposing metal stents or self-expandable metal stents for endoscopic ultrasound-guided choledochoduodenostomy: a systematic review …
2020
Abstract Background Endoscopic ultrasound (EUS)-guided biliary drainage is becoming an option for palliation of malignant biliary obstruction. Lumen-apposing metal stents (LAMS) are replacing self-expandable metal stents (SEMS). The aim of this meta-analysis was to evaluate the efficacy and safety of LAMS and SEMS for EUS-guided choledochoduodenostomy (EUS-CDS). Methods A meta-analysis was performed using PRISMA protocols. Electronic databases were searched for studies on EUS-CDS. The primary outcome was clinical success. Secondary outcomes were technical success, reintervention, and adverse events. We used the random effects model with the DerSimonian–Laird estimation, and the results were…
Closed-form solutions of the energy balance equation for drip laterals under the Darcy-Weisbach resistance formula
2018
Many studies have investigated easy methods to design drip laterals, as well as the best resistance equation to use, which is fundamental to accurately account for friction losses. This paper addresses both the features of lateral design relationships and the influence of the friction-loss equation on the design variables. First, simple closed-form solutions of the energy balance equation for both sloped and horizontal drip laterals are derived with the simplified Darcy-Weisbach resistance formula by assuming the Darcy friction factor as invariant versus the Reynolds number. Second, an error analysis is performed assuming the friction factor as constant in the design, which is compared to u…
Water need of Energy Crops – one of the environmental problems of Poland
2010
The government policy updates of Poland are presented, showing legal and financial instruments for governing bioenergy developments. The strategy for renewable energy must be co-ordinated with the strategy of water management in the country. The water needs are given for cool climate and extensive agriculture of Central and Eastern Europe which are few times lower than for hotter condition of Southern Europe. Despite this the rain would be not enough for water supply of most of the energy crops.
Dimensional analysis and stage-discharge relationship for weirs: a review
2017
Deducing the weir flow stage-discharge relationship is a classical hydraulic problem. In this regard Buckingham’s theorem of dimensional analysis can be used to find simple and accurate formulas to obtain the rating curves of different weir types. At first, in this review paper the rectangular weir that is a very common hydraulic structure is studied. It is indicated that the crest shape, approach channel width, obliquity (angle between the weir crest and the direction normal to the flow motion) and vertical inclination (pivot weir) are the key-parameters affecting the flow over the rectangular weirs. The flow over the triangular, labyrinth, parabolic, circular, elliptical, and W-weirs are …
Testing mechanical characteristics of chestnut stakes used in bed sills for stream restoration
2017
Using of wood elements for constructing bed sills in Mediterranean streams, where the banks are not protected by tree vegetation, needs an evaluation of biological and mechanical characteristics for evaluating both the wood durability and the effectiveness of the stream restoration project. Very few studies have dealt both with the decay of mechanical characteristics of wood elements employed for stream restoration works and with the changes over time of physical and chemical wood characters. In this paper, for a wood and stone bed sill located in a stream having no shaded banks, the changes of physical and chemical characters detected after 12, 18, 24, 30, 36, 42 and 48 months on chestnut …