1,730 research outputs found
Prediction of maximum oxygen uptake from a modified Ymca 3-minute step test
The relationship between post exercise recovery heart rate (PERHR) and maximum oxygen uptake using a height specific bench with a modified Young Men\u27s Christian Association (YMCA) 3-Minute Step Test was investigated. Sixty apparently healthy males and females between the ages of 18 and 55 years stepped on a height specific bench for 3 minutes in order to obtain their 1-minute and 15-second post exercise recovery heart rates. An EKG monitored post exercise recovery heart rates. Maximum oxygen uptake was measured by open circuit spirometry on a motor-driven treadmill. Correlation and regression statistics were used to analyze the data. Results indicate a significant correlation between the 1-minute PERHR and maximum oxygen uptake (r =.5796, r{dollar}\sb{\rm critical}{dollar} =.2108) and a significant correlation between the 15-second PERHR and maximum oxygen uptake (r =.5428, r{dollar}\sb{\rm critical}{dollar} =.2108)
Monitoring of Plant Species and Communities on Coastal Cliffs: Is the Use of Unmanned Aerial Vehicles Suitable?
Cliffs are reservoirs of biodiversity; therefore, many plant species and communities of inland and coastal cliffs are protected by Council Directive 92/43/EEC (European Economic Community), and their monitoring is mandatory in European Union countries. Surveying plants on coastal cliff by traditional methods is challenging and alternatives are needed. We tested the use of a small Unmanned Aerial Vehicle (UAV) as an alternative survey tool, gathering aerial images of cliffs at Palinuro Cape (Southern Italy). Four photo-interpreters analysed independently the derived orthomosaic and plotted data needed for the monitoring activity. Data showed to be not affected by photo-interpreters and reliable for the prescribed monitoring in the European Union (EU). Using the GIS analysis tools, we were able to: (a) recognise and map the plant species, (b) derive and measure the area of distribution on the cliff of habitat and species, and (c) count Eokochia saxicola individuals and gather quantitative data on their projected area. Quality of the images represented the main constraint, but incoming technological improvements of sensors and UAVs may overcome this problem. Overall results support the use of UAVs as an affordable and fast survey technique that can rapidly increase the number of studies on cliff habitats and improve ecological knowledge on their plant species and communitie
A System for the Real-Time Geo-Referenced Measurement of Soil Parameters
The aim of this research is to develop a system for accurately measuring in real-time, collecting and processing a high amount of geo-referenced data of soil physical-mechanical parameters, e.g. cone penetrometer resistance, index of soil compaction, and draft force.
The system for measuring the soil cone penetrometer resistance is comprised of a load cell, connected to a rod, ending with a cone, and is mounted on a frame, fixed to the front part of a tractor. The system for measuring the draft force required to till the soil is comprised of a load cell, mounted on the hitch hook of a tool carrier, towed by the tractor. Moreover, in order to test the usefulness of the system with different types of linkage tractor-implement, two other load cells were mounted, respectively, on the top link and the right point of the three-point hitch of the tool carrier. The signals of the load cells and of a DGPS mobile receiver are acquired by a portable computer, by means of a Virtual Instrument developed in LabVIEW environment.
The results of the first tests, carried out in a field in inland Sicily, showed that: the system is able to log data with a sampling frequency adjustable from 1 to 10 Hz; it is able to accurately measure and collect in real-time a large amount of data, which can be easily processed by means of a data sheet, a GIS or another software usable for measuring the within-field spatial variability of soil physical-mechanical parameters; the absolute value of the force measured on the hitch hook of the tool carrier is proportionally correlated to that measured on any point of the three-point hitch of the same one
Effect of high level of bladder filling on spinal nociception and motoneuronal excitability
To verify whether high level of bladder distension may counteract the inhibitory effect of descending pathways on sacral spinal cord neurons and to investigate which spinal circuitries are possibly involved in such a viscero-somatic interaction. Nociceptive withdrawal reflex (NWR), cutaneous silent period (CSP), and H-reflex were recorded in both lower and upper limbs of twenty-eight healthy subjects. Subjects were examined during baseline (empty bladder, no voiding desire), high level of bladder filling (urgency desire), and control (empty bladder, no voiding desire) sessions. Results showed that the NWR and its related pain perception were reduced in the upper limbs, while only a pain perception reduction in males was observed in the lower limbs. The H-reflex was inhibited in both limbs. No effects were found on the CSP duration. The decrease in both the NWR and its related pain perception in the upper limbs confirms the presence of a bladder distension-induced descending inhibitory modulation on nociception at spinal level. The lack of a similar inhibitory effect in the lower limbs suggests that excitatory nociceptive inputs from bladder afferents counterbalance the inhibitory effect on sacral spinal cord. The lack of the descending inhibitory effect may be a mechanism aimed at forcing the micturition phase to avoid bladder damage caused by bladder sovradistension
combined activation of braking and steering for automated driving systems adaptive intervention by injury risk based criteria
Abstract Increase in advanced driver assistance systems (ADAS) performances is a crucial step towards autonomous driving, allowing the design of increasingly reliable automated driving systems (ADS); ADAS devices play a key role in the enhancement of vehicle safety, which primarily results from the ability to avoid possible impacts. Nevertheless, inevitable collision states (ICS) can be triggered by obstacles as buildings and stationary vehicles interposing between the opponent and the working field of ADAS sensors, compromising their functions; therefore, the performance increase of ADAS devices on the market necessarily passes from the optimal handling of an ICS, which is not currently subject to evaluations. The work introduces ADAS intervention criteria which are based on the occupants' injury risk (IR): in a specific road scenario, the ADAS must primarily avoid the collision with maximum margin and minimize IR in the case of an ICS. Specifically, the ADAS must monitor the environment and intervene on braking and steering adapting to the scenario evolution, following an "adaptive" logic. The most critical aspect of the approach lies in reconstructing, for the specific intervention, the eventual impact: while being a time-consuming process, reconstruction of the impact phase is necessary to compute impact-related parameters (e.g., velocity change of the vehicle ∆V) which directly affect IR. To highlight the benefits offered by an adaptive ADAS compared to traditional ADASs, a special testing software has been developed: the best adaptive intervention to be applied at each instant is chosen in real-time through the criteria proposed, retrieving the required information from a pre-calculated database which collects the results of each braking and steering manoeuvre for a large variety of critical scenarios. Analyzing three ICS conditions, it is shown that the adaptive logic, differing from an autonomous emergency braking, aims at creating eccentrical impacts with minimum ∆V: the IR values associated with the ADAS adaptive intervention are consequently an order of magnitude lower than those obtained through traditional ADAS interventions
Italian Potential Biogas and Biomethane Production from OFMSW
This work is aimed at predicting the potential biogas and biomethane production, using the Organic Fraction of Municipal Solid Waste (OFMSW), in Italy, where 1388 Anaerobic Digestion (AD) plants (power of 7.4 TWh, equal to 640.4 ktep) are nowadays available.
In order to compute the potential biogas and biomethane production in the 20 Italian regions, the data about OFMSW production in 2010-2013 period have been evaluated.
The Italian production of OFMSW, that was 5.2 million tons in 2013 (18% of MSW), could be used inside bioreactors for producing biogas and digestate, that must be aerobically composted into a biofertiliser. In 2013, the Italian potential biogas production from OFMSW was 739 million m3, that is equal to 444 million m3 of biomethane. The highest biogas production from OFMSW was in Lombardy region (143 million m3), having a potential biomethane production of 86 million m3. The highest OFMSW production per inhabitant was in Emilia-Romagna region (142 kg). Yet, if OFMSW was 37% of MSW, the potential biogas and biomethane production should be increased: the biomethane production increase would be 486 million m3, of which the maximum would be in Sicily region.
The biogas produced can be used for generating heat and electricity or upgraded into biomethane, distributed at dedicated stations and useful as biofuel for powering means of transport. This biofuel would replace natural gas, and, therefore, allow a reduction of GreenHouse Gas emissions of 200 g of CO2 kWh-1 (5.5 times lower) and the import of fossil fuels from abroad
A System to Simplify the Use of Mounted Shakers for Harvesting Olives and Dry Fruits
The shakers for harvesting olives and dry fruits have reached a high standard and their use is increasing rapidly.
In order to satisfy the different demand, manufacturers offer a wide range of shakers, from the more expensive self-propelled ones to those to be mounted on the tractor’s power lift, with shaking headers of different mass and size, suitable for the different orchard characteristics.
Self-propelled shakers have high steering capacity and optimum visual field for the operator, so their working capacity is very high with respect to that of mounted shakers, which are less expensive but have lower steering capacity and a limited view on the header. Therefore the approaching of mounted shakers to the plant and the fastening of the header to the trunk or branch of the tree is more difficult, and a second operator to pilot the tractor driver is needed, in order to increase the machine working capacity and to avoid plant and/or shaker damages.
This paper proposes to use a system composed of a CCD video camera, installed on the frame of a mounted shaker and connected to a TFT monitor, fitted in the tractor cab.
Comparative tests with and without the above system were carried out. The video camera was mounted on the shaker frame.
The system is relatively cheap, user-friendly and can be mounted on any shaker. It provides the driver with an easy view of the lower dead angle and increases the working capacity and productivity of the machine
A system for spatially variable rate fertiliser application
The crop yield can be spatially variable within the same field, because of spatially variable soil characteristics (slope, texture, pH, etc.), influencing the soil nutrient content (of nitrogen, phosphorus, potassium, etc.).
Because of this within-field spatial variability, in the precision agriculture cycle, the targeted fertiliser spreading can be highly profitable for both environment protection and cost saving.
For this aim the yield and, then, the soil nutrient content must be measured on a localised basis and, therefore, mapped. Relying on the yield map and on the map of each nutrient available in the field it is possible to produce the fertiliser application map, which must be stored on a portable computer, in order to perform the spatially variable rate fertiliser spreading.
For this aim an electronic system able to apply fertiliser rates proportionally related to the machine forward speed is also needed; this system can be mounted not only on any pneumatic spreader but also on any centrifugal spreader with setting up system working by gravity.
Yet, the fertiliser spreaders produced by different manufacturers, which are equipped with systems able to apply not only rates proportionally related to machine forward speed but also spatially variable rates, are very expensive.
Therefore, the I.T.A.F. Department designed, developed and set up a system for spatially variable rate fertiliser application, compatible with most DGPS and spreaders able to apply rates proportionally related to the machine forward speed.
The system is constituted by a data sensing system (DGPS and Doppler radar), a data processing system (portable computer, with a specifically developed software called Precision Agriculture Controller) and an active and control system (Land Manager of DICKEY-john with built-in display and keyboard), able to apply rates proportionally related to machine forward speed, by varying the size of the two hopper openings.
The software is able to: receive and interpret DGPS position data and compare them with the fertiliser application map, in order to identify the rate related to the actual machine position; transmit commands to Land Manager; log the machine track and the applied rates
Dinamica della sincronizzazione nel modello di Kuramoto
In questo lavoro andiamo a testare facendo uso di simulazioni numeriche il modello di sincronizzazione spontanea ideato da Kuramoto. Viene inoltre presentata un’approssimazione empirica della dinamica della coerenza per il limite di popolazione di oscillatori infinita.ope
Shape Memory Composites for Self-deployable Structures in Aerospace Applications
AbstractShape memory composites (SMCs) are attractive materials as they combine typical mechanical and functional properties of composites with shape memory properties. Such properties can be given to composite materials and structures by using shape memory polymer (SMP) matrices or integrating parts made of SMPs. In the case of integration, flexible composite skins can be applied over a shape memory foam core obtaining composite sandwich that can be shaped to change its stiffness or to reduce its volume. After the application of a given stimulus (generally by heating) the initial shape can be recovered. Future applications for this class of materials are self-deployable structures for space systems (such as actuators of solar sails or smart aerodynamic structures). In this work, two new SMC self-deployable structures were prototyped: a composite cross and a composite frame containing a thin aluminum sheet. The former structure represents a possible deploying configuration for a structural sheet whereas the latter is a conceptual study of a solar sail. The experimental results are very promising, showing that such structures can successfully self-deploy following the desired design constraints without noticeable damages. Finally, new perspectives for applications are highlighte
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