Showing papers by "Demetres Briassoulis published in 2008"

Plastic nets in agriculture ; a general review of types and applications

Abstract: At the moment, there are a large number of agricultural net types on the market characterized by different structural features such as type of material, type and dimensions of threads, texture, mesh size, porosity / solidity and weight; by radiometric properties like color, transmissivity/reflectivity/shading factor; by physical properties like air permeability and several mechanical characteristics such as tensile stress, strength, elongation at break, and durability. Protection from hail, wind, snow, or strong rainfall in fruit-farming and ornamentals, shading nets for greenhouses and nets moderately modifying the microenvironment for a crop are the most common applications. A systematic review of the current state-of-the-art of structural parameters, standard and regulations, most common agricultural net applications, and their supporting structures has been developed by means of a literature study, technical investigations, concerning characteristics and use of nets. As a result, the survey highlighted that in many cases different, not even similar, net types were adopted for the same application and the same cultivations by various growers. Results show that neither growers nor net producers have clear ideas about the relationship between the net typology optimization for a specific application and the construction parameters of the net. The choice often depends on empirical or economic criteria and not on scientific considerations. Moreover, it appears that scientifically justified technical requirements for nets used in specific agricultural applications have not been established yet.

Design and use criteria of netting systems for agricultural production in italy

Abstract: At the moment, there is a large number of agricultural net typologies on the market characterised by different texture features such as threads, texture, dimensions of fibres and meshing, physical properties such as weight, colours, shading factor, durability, porosity, air permeability and mechanical characteristics such as stress, strength at break and elongation. Protection from hail, wind, snow, or strong rainfall in fruit-farming and ornamentals, shading nets for greenhouses, or nets for moderately modifying the microenvironment are the most common applications. A systematic review of the current state-of-the-art of structural parameters, standard and regulations, most common agricultural applications of nets and their supporting structures has been developed by means of a literature study, technical investigations, interviews with permeable covering producers, specialised greenhouse builders and growers, who are familiar with permeable cladding applications. The interviews were based on questionnaires concerning characteristics, use and disposal of nets. As a result, the survey highlighted that in many cases different, not even similar, net typologies were adopted for the same application and the same cultivations by various growers. Results show that neither growers nor net producers have clear ideas about the relationship between the net typology optimisation for a specific function and the construction parameters of the net. The choice still depends often on empirical or economic criteria and not on scientific considerations. Moreover, it appears that scientifically justified technical requirements for nets used in specific agricultural applications have not been established yet.

The emerging evolution from Agricultural Engineering to Biosystems Engineering studies in Europe

Abstract: The main objectives of a new European Thematic Network entitled ‘Education and Research in Biosystems Engineering in Europe (ERABEE-TN)’ is to initiate and contribute to the structural development and the assurance of the quality assessment of the emerging discipline of Biosystems Engineering in Europe. To date, very few Biosystems Engineering programs exist in Europe and those that are initiated are at a very primitive stage of development. The innovative and novel goal of the Thematic Network is to promote this critical transition, which requires major restructuring in Europe, exploiting along this direction the outcomes accomplished by its predecessor; the USAEE-TN (University Studies in Agricultural Engineering in Europe). It also aims at enhancing the compatibility among the new programmes of Biosystems Engineering, aiding their recognition and accreditation at European and International level and facilitating greater mobility of skilled personnel, researchers and students.