404 research outputs found
Effect of seed-beds on the cultivation of Radicchio (Cichorium intybus L., Rubifolium group)
The use of raised beds (i.e., ridged soil layers) to cultivate vegetables can improve soil quality, crop performance, water use and even reduce soil erosion. Although those advantages are well known and documented in the literature for many vegetable species, Radicchio, a particular variety of chicory, is usually cultivated in flat seed-beds and, therefore, the achievable benefits of raised beds for this vegetable are not yet known. The possibility to grow plants of Radicchio on raised beds is here evaluated by comparing the most important yield performances indicators deriving from the adoption of this practice (grown plants percentage, average head weight, marketable yields, and net incomes) with the same indicators recorded with a conventional practice making use of flat seed-beds. The results evidenced that raised beds for Radicchio had a statistically significant effect on the average head weight (+55.45 g plant-1 with 15-cm beds) with significant increases of field yields (up to +30.6%) and net incomes (up to +29.7%) on the trials with flat seed-beds. The experiment showed that the production of chicory can take an economical advantage from the use of raised seed-beds and, therefore, this system is preferable to the traditional cultivation practice
Efficiency & sustainability model to design and manage two-stage logistic networks
The distribution and storage efficiency together with the environmental sustainability are mandatory targets to consider when designing and managing modern supply chain (SC) networks. The current literature continuously looks for quantitative multi-perspective strategies and models, including and best balancing such issues that often diverge.
This paper presents and applies a bi-objective optimization model to best design and manage two-stage logistic networks looking for the best trade-off between the SC stock level and the building and distribution environmental impact. The existence of good balance confirms the possibility to reduce the average SC stock level without a relevant increase of the emissions due to frequent replenishments
Design, control and management of renewable energy plants and technologies
Nowadays, and even more in the next decades, the availability and easy-access to energy sources represent a crucial asset for the world development and the progress of people and nations. At the same time, the depletion of natural resources, together with the increase of the anthropic activity impact on the Earth ecosystem and climate, force communities and institutions, at all levels, to discuss and actuate different approaches to achieve the social and economic growth, based on the so-called sustainable development pattern. In such a scenario, renewable energy sources, i.e. solar, wind, hydro, biomass, geothermal, etc., certainly play a key role to join progress and attention to the environmental issues.
The present Ph.D. dissertation focuses on such topics investigating strategies, methods and innovative approaches for the effective design, control and management of renewable energy plants and technologies.
Specifically, the energy scenario is investigated from a global point of view proposing studies and optimization models highlighting the relevance and the potential impact of the major energy sources, both renewable and conventional. Such sources represent the elements of a big puzzle, i.e. the energy mix, in which their economic and environmental strengths should be emphasized minimizing the associated negative impacts and weaknesses.
Among renewable sources, solar energy is of primary importance for availability, diffusion and potential impact. The present Ph.D. dissertation particularly investigates such a source presenting models, methods and prototypes to increase its relevance in the energy mix. The fundamentals of solar energy, together with innovative approaches to estimate the solar radiation components, are provided. Furthermore, the pioneering concentrating solar sector is deeply focused presenting the design, development and preliminary field-test of a bi-axial Fresnel solar photovoltaic/thermal (PV/T) concentrating prototype. Possible solar tracking strategies and control algorithms are, then, investigated describing a customized semi-automatic motion control platform, developed in LabViewTM programming environment. Finally, the last section, proposes an effective approach for the design of a solar simulator, the most frequently adopted device in solar optic laboratory tests.
In conclusion, the present Ph.D. dissertation describes effective strategies for the renewable energy spread, considering their performances and their potential impact to achieve the ambitious challenge of a sustainable living planet
dynamic design and management of reconfigurable manufacturing systems
Abstract This research proposes an approach to design and to manage Cellular Reconfigurable Manufacturing Systems (CRMSs) from a multi-product and multi-period perspective. The production environment consists of multiple cells of machines equipped with Reconfigurable Machine Tools (RMTs) made of basic and auxiliary custom modules to perform specific tasks. The approach acts into two steps; the former is the machine cell design phase, assigning machines to cells, the latter is the cell loading phase, assigning modules to each machine and cell. The goal is to guarantee the economic sustainability of the manufacturing system by exploring how to best balance the part flow among machines already equipped with the required modules and the effort to install the necessary modules on the machine on which the part is located
A cross‐sectorial review of industrial best practices and case histories on Industry 4.0 technologies
Industry 4.0 (I4.0) was introduced in 2011, and its advanced enablers strongly affect industrial practices. In the current literature, while several papers offer general reviews on the topic, contributions exploring the evidences coming from the implementation of I4.0 in multi-sector Small and Medium Enterprises (SMEs) and large enterprises are few and expected. To address this gap, a comprehensive review of the main I4.0 enabling technologies is conducted, focusing on implementation experiences in companies belonging to different sectors. Forty (40) real case studies are analyzed and compared. The results show that 63% of the identified applications involve large enterprises in the transport sector, that is, automotive, aeronautics, and railway, adopting a structured set of enabling technologies. SMEs engaged in I4.0 projects primarily belong to the mechanical engineering sector, and 37% of such projects deals with the preliminary feasibility analysis of introducing a single enabling technology. Conclusions and trends guide researchers and practitioners in understanding the implementation level of I4.0 technologies
Automatic assessment of the ergonomic risk for manual manufacturing and assembly activities through optical motion capture technology
Abstract Safeguard the operator health is nowadays a hot topic for most of the companies whose production process relies on manual manufacturing and assembly activities. European legislations, national regulations and international standards force the companies to assess the risk of musculoskeletal disorders of operators while they are performing manual tasks. Furthermore, international corporates typically require their partners to adopt and implement particular indices and procedures to assess the ergonomic risks specific of their industrial sector. The expertise and time required by the ergonomic assessment activity compels the companies to huge financial, human and technological investments. An original Motion Analysis System (MAS) is developed to facilitate the evaluation of most of the ergonomic indices traditionally adopted by manufacturing firms. The MAS exploits a network of marker-less depth cameras to track and record the operator movements and postures during the performed tasks. The big volume of data provided by this motion capture technology is employed by the MAS to automatically and quantitatively assesses the risk of musculoskeletal disorders over the entire task duration and for each body part. The developed hardware/software architecture is tested and validated with a real industrial case study of a car manufacturer which adopts the European Assembly Worksheet (EAWS) to assess the ergonomic risk of its assembly line operators. The results suggest how the MAS is a powerful architecture compared to other motion capture solutions. Indeed, this technology accurately assesses the operator movements and his joint absolute position in the assembly station 3D layout. Finally, the MAS automatically and quantitatively fill out the different EAWS sections, traditionally evaluated through time- and resource-consuming activities
implementation of reconfigurable manufacturing in the italian context state of the art and trends
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effects of water distribution uniformity on waxy corn zea mays l yield preliminary results
To face climatic changes, the increase of frequency and severity of droughts, and economic development pressures, Water Management Institutions point at the necessity of water conserving. A sustainable demand-led approach is the most viable option, focusing on achieving more efficient irrigation practices instead of less sustainable expansion of supply. The aim of this work is to investigate on some aspects of the rational water management for the irrigation of corn in order to evaluate the actual possibility of introduction of drip irrigation systems on the Venetian Plain. Trials were carried out on a farm located in Isola della Scala (Verona, Italy) in an area of about 13 ha (12 ha with a drip irrigation system and 1 ha with a solid-set sprinkler system); the effects of the performance of the two systems on waxy corn yield were considered. In particular, water distribution uniformity, water use efficiency, and yield performance of irrigation systems were evaluated. DUlq and CU coefficients for distribution uniformity and IWUe and WUEb indexes for water use efficiency were calculated. To visualize and better analyze the distribution uniformity, the crop yield and the efficiency parameters, ArcGIS 10 (ESRI?) with IDW interpolation were used to create maps. First results show a good water uniformity distribution in the drip irrigation system but only with a careful and proper design of the entire system. As regards the water use efficiency, drip irrigation values are lower than those of sprinkler irrigation (-46% for IWUe and -25% for WUEb), probably due to different irrigation management and water volumes used: in fact, drip irrigation was scheduled every three days, while only supplemental operations were done for sprinkler irrigation. No statistical correlation was found between application rate and yield for both irrigations systems, while a significant correlation was found between irrigation volume and crop water use efficiency. The profitability of the two irrigation systems was compared. The results show that the income of drip irrigation is slightly lower than sprinkler irrigation, mostly due to the use of "throw away" drip lines
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