AGISGRID: applicazioni GIS distribuite

2006-11-28Sardegna Ricerche, Edificio 2, Località Piscinamanna 09010 Pula (CA) - ItaliaKick-off Meeting del Progetto GRIDA

A standardized morpho-functional classification of the planet’s humipedons

It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morphofunctional classification of humipedons (roughly the top 30–40 cm of soil: organic and organomineral surface horizons) would allow for a better understanding of the functioning of the soil ecosystem. This paper provides the founding principles of the classification of humipedon into humus systems and forms. With the recognition of a few diagnostic horizons, all humus systems can be determined. The humus forms that make up these humus systems are revealed by measuring the thicknesses of the diagnostic horizons. In the final part of the article, several figures represent the screenshots of a mobile phone or tablet application that allows for a fast recall of the diagnostic elements of the classification in the field. The article attempts to promote a standardized classification of humipedons for a global and shared management of soil at planet level

The Influence of short-term land use change on soil evolution in the centre-south coastal areas of Sardinia

The land use change in short-term (time and space) in the Mediterranean context can be induced by phenomena like destruction of the autochthonous plant species, land abandonment, overgrazing, fire, urbanization (above all for touristic purpose), etc. These phenomena can lead to soil’s degradation conditions causing a loss of physical and biological productivity and the consequent emphasis in desertification processes. Desertification is considered one of the biggest environmental problems in Mediterranean areas (ICCD, 1994), and Sardinia is one of the most affected regions in Europe (UNEP, 1992; Imeson and Emmer, 1992). In Sardinia changes happened during the last decades (such as industrialization, coastal urban areas expansion, etc.) have often resulted in repercussions on the environmental ecosystems and foremost on soils. An important decrease of fertile lands and a consequent increase of marginal and unproductive areas have been observed; this fact has taken to manifest environmental and economic repercussions. In Sardinia such degradation phenomena are particularly evident in coastal areas, where the uncontrolled urbanization and the natural touristic vocation represent relevant impact types. In fact, in 1897 km of coastal lands (500 km are represented by dunal systems) 40% is subjected to deep erosion phenomena, that often are caused by wrong management actions. For these reasons the knowledge of their nature and expansion is of primary importance to carry out correct choices in land use. This work shows an example of a comparative investigation on coastal ecosystems particularly under human pressure. The investigated areas are located along the Centre–North coast of Sardinia. Particularly they concern: a) soils on limestone formations, forestry live oak cover and pasture land use (goat and swine); b) soils on fixed dunes, reforestation with pine and touristic-recreational land use foremost. In the areas several soil profiles have been realized to investigate the influence of the land use change, occurring in short-term in both places, on the evolution and degradation processes of soils

Crane Shaking Platform Design

Most of the control methodology of Mobile hydraulic crane is not as energy efficient as people think or want, and the desire to innovate novel, energy-efficient control strategy is the target of most hydraulic experts. To develop or test the control method under real road and off-road conditions, a platform that could simulate the movement and vibration of the crane truck is desired. To design and build the multi-operation platform, a design process includes brain storming, design selection, FEA (Fundamental Element Analysis), mechanical sizing, hydraulic sizing and Bill of Material is required and preferred. After going through all the steps mentioned above, the design that use simple cylinders in the vertical position has been selected, and the proper dimension has been settled down. Most of the part are directly sponsored by Parker, CO, the sponsor of MAHA lab. The design method and process is duplicable and could be used to design other similar or relative products

Design of a Novel Actuation System for Variable Displacement Gear Machine

External spur gear pumps are exceedingly useful components in common hydraulic systems. The main issue with external gear pumps is that all current models are limited to only fixed-displacement. This means that for every revolution of the gears inside the pump, a set amount of fluid will always be displaced. Consequently, external gear pumps are limited in their use because they can only operate at full throttle causing inefficiencies when reduced displacement is needed. The successful procurement of a variable displacement gear pump will allow a more efficient use of hydraulic systems, such as in the displacement controlled systems used in some heavy construction equipment. In this research approach, the displacement is varied by changing the timing of the gears inside the pump. More specifically, changing the timing of the gears’ connections with the inlet and outlet grooves alters the available volume in the gears’ spaces, subsequently varying the displacement. With this in mind, additional research was conducted to develop an actuation system for the aforementioned process. This includes the design of new gears, bearing blocks, and additional hydraulics for use in a modified existing commercial pump. Simulations have shown the implementation of the design allowed for a 67% reduction in displacement, and thus successful introduction of variable displacement into an external gear pump. Additional research is needed to determine the optimal designs for the actuation system and variable displacement concept used in the gear pump

A Flow Control System for a Novel Concept of Variable Delivery External Gear Pump

This paper describes a novel concept for a low cost variable delivery external gear pump (VD-EGP). The proposed VD-EGP is based on the realization of a variable timing for the connections of the internal displacement chambers with the inlet and outlet ports. With respect to a standard EGP, an additional element (slider) is used along with asymmetric gears to realize the variable timing principle. Previously performed tests confirmed the validity of the concept, for a design capable of varing the flow in the 65%-100% range. Although the VD-EGP concept is suitable for various flow control system typologies (manual, electro-actuated, hydraulically flow- or pressure- compensated), this paper particularly details the design and the test results for a prototype that includes both a manual flow control system and a pressure compensator. Flow vs pressure and volumetric efficiency curves are discussed along with transient (outlet flow fluctuation) features of the VD-EGP

A Quali-quantitative evaluation approach to pedodiversity by multivariate analysis: introduction to the concept of "pedocharacter"

A model has been developed for the interpretation of the complexity of pedological systems; this is referred to as “pedocharacter”. The main aim of the model was to reduce the variables able to define soils and their relationships with the environment through the following quali-quantitative approach: i) definition of a fair number of qualitative characters; and ii) development of an analytic function, defined as “Land Relevance of the Factor”

Validation of Lateral Gap Leakage Objective Function for Use in Multi-Objective Optimization of Gerotor Pumps

Gerotor pumps are a common pump choice used in the automotive, agricultural, and construction fields for their low cost and durability. Recently, demanding applications have called for significant design improvements in gear geometry. To address these design challenges, multi-objective optimization has been applied to gear geometry. The goal of this work is to introduce minimizing of lateral-gap leakage to the multi-objective optimization. An objective function for evaluating lateral-gap leakage based on 1D, pressure driven flow is proposed. This simplified approach is compared to CFD simulation solving of Reynolds equation with two pressure boundaries. Comparison of the simplified relation and the CFD simulation are used to validate the objective function for use in optimization

Design of A Test-Rig for Gerotor Pump

Gerotor pumps are a kind of fluid power machines widely used in the automotive field, especially for fuel injection as well as lubrication. To improve the performance of these units, virtual prototyping is necessary to decrease time and cost related to trial and error. Within this research a simulation model for Gerotor units has been developed with the aim of predicting accurately the performance of a generic unit. The model can accurately predict the system behavior regarding mechanical and volumetric losses by considering real machining tolerances and their interactions. Ultimately, this model should help to design new generations of Gerotor units and to improve existing ones by improving their efficiency. To justify and refine the model, a test-rig which can enable measurements of rotor micro-motions of the gears of Gerotors is needed. This paper proposes an innovative approach for measuring micro-motions together with the design of a test-rig specifically conceived to allow such measurements. Reference Gerotor units will be put in a specially designed pump housing. The measurements will be performed using capacitive sensors capable of measuring the lubricant film thickness in the lubricated gaps. In this way, the micro-motions of the reference Gerotor unit can be detected. A data acquisition system will be created to collect the experimental data. Results will be analyzed to understand the correctness of the prediction given by the model. With these results, the lumped parameter model is expected to be validated or refined allowing more precise predictions in the future