Engineering problems and aspects of the technological equipment in Space Plant Growth Systems

As human presence in space becomes longer, supplying all food, oxygen and water from Earth will result in a tremendous cost. For this reason the international scientific community has been making efforts towards developing technologies and equipment to realise a sustainable Bioregenerative Life Support System for food production, water purification, air revitalisation and waste recovery. Plants produce food and oxygen for human needs, contribute to remove and reclaim carbon dioxide, relative humidity and the organic wastes. Aim of this research is a critical analysis of the materials and equipment requirements used up to now, in order to highlight the equipment engineering solutions for a system for plant cultivation on-board the International Space Station supported by Italian Space Agency. Creating a Bioregenerative Life Support System is an extremely sophisticated scientific problem. Space environment is characterised by the absence of the Earth’s gravitational and magnetic fields, of tidal forces and of the influence of the cyclical events of celestial mechanics and so, the prediction of fluid and heat behaviour is less intuitive. Besides, this environment would severely impact plant growth and metabolism. In space an enclosed environmentallycontrolled plant growth system must control and regulate the atmospheric parameters and the atmospheric gas composition, provide light energy for photosynthesis and supply the plants with the appropriate nutrient and water to support photosynthesis and to compensate for the evaporation and transpiration losses

Structural design and experimental tests on a model of tensegrity greenhouse prototype

The aim of this paper is the analysis, proposal and application of a structural tensegrity configuration for greenhouses supporting structures suitable for lightweight covering, based on principles of design coherence, material savings and building durability.By means of the FEM software, Sofistik (R), a tensegral greenhouse prototype was modelled and designed in accordance with EN 13031-1:2019.In order to calibrate the results of the FEM analysis, experimental load tests and displacement measurements made with a tensegrity reduced scale model on a tensegrity reduced scale model, created at the Department laboratory of the University of Bari, were compared with the results of the calculation analysis. The displacements of the prototype selected nodes were detected by Target tracking Technology in two load configurations and a control transducer was positioned on the central structural node. The comparison among the displacements of the detected nodes with those resulting from the FEM software calculations, for two different load configurations, show average percentage errors of 7.1% and 12.55%. The results of the T test for the different load configuration point out that the two series of values experimentally detected and calculated by the software are not significantly dif- ferent. Finally, results in terms of the structural steel weight and maximum stress of the tensegral structure were compared with those of commercial structures, both with vaulted roof and duopitched roof, of single span greenhouses having the same covered ground area of the greenhouse prototype. The proposed tensegrity greenhouse prototype showed a 9.6% and 35.2% reduction of the structural steel weight compared to the vaulted roof and to the duo-pitched roof greenhouse respectively

The medieval pilgrims routes in the Apulian settlements and their relationship with Rome and Santiago de Compostela

The medieval pilgrims routes in the Apulian settlements and their relationship with Rome and Santiago de Compostela The Medieval cave settlements and cave churches in the Apulia region, in southern Itlay, created with their frescoes, along the pilgrims roads and the Ancient Appia route, a connection with the grave of Saint James in Santiago de Compostela. Indeed during the Middle Age the Church and the local nobles and feudatories used the Apulian medieval pilgrims’ routes for religious and marketing purposes linking Apulian Cave frescoes churches with Santiago de Compostela, therefore one of the aim of the research is to retrace the pilgrims routes basing on the images of the Saints painted in some frescoes and to create a veritable virtual link of the Apulian medieval cave churches with Saint James’ tomb in Santiago de Compostela thanks to the representation of the Saint bringing the pecten iacobeus (shell of St. James) and the Pilgrim’s bagshow. Aim of the research, applied to the proposed study area of the ravines and cave churches of Apulia, is to analyse, plan and restructure the ancient routes and livestock trail paths of the area by means of the files found in the archives in order to “redraw” the historical, social and environmental landscape and present it as paths with strong touristic interest with reference to the Apulian ravines area, the agricultural and forest landscapes and the traditional farmhouses

PLASTIC MATERIALS IN EUROPEAN AGRICULTURE: ACTUAL USE AND PERSPECTIVES

The world consumption of plastics in agriculture amounts yearly to 6.5 million tons. In addition to conventional polymers used in agriculture for greenhouses and mulches such as PE, PVC, EVA, photo-selective and luminescent polymers have been used, in order to improve the quality of crops. For the same reason plastic nets are used mainly in countries with tropical and Mediterranean climates. For an environmentally friendly agricultural activity, an alternative strategy can be represented by bio-based agricultural raw materials. For low environmental impact applications, biodegradable materials for agricultural films are nowadays produced. An overview of the main methods for the disposal and recycling of plastic materials are presented with the results of mechanical and radiometric tests on recycled plastics. The strategies to reduce the burden of plastics in agriculture are: a correct procedure for the collection, disposal and recycling of post-consumption plastics; the increase of lifetime duration and performance; and the introduction and promotion of bio-based materials

Fifty years of the Journal of Agricultural Engineering

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Electrolyzer performance analysis of an integrated hydrogen power system for greenhouse heating a case study

A greenhouse containing an integrated system of photovoltaic panels, a water electrolyzer, fuel cells and a geothermal heat pump was set up to investigate suitable solutions for a power system based on solar energy and hydrogen, feeding a self-sufficient, geothermal-heated greenhouse. The electricity produced by the photovoltaic source supplies the electrolyzer; the manufactured hydrogen gas is held in a pressure tank. In these systems, the electrolyzer is a crucial component; the technical challenge is to make it work regularly despite the irregularity of the solar source. The focus of this paper is to study the performance and the real energy efficiency of the electrolyzer, analyzing its operational data collected under different operating conditions affected by the changeable solar radiant energy characterizing the site where the experimental plant was located. The analysis of the measured values allowed evaluation of its suitability for the agricultural requirements such as greenhouse heating. On the strength of the obtained result, a new layout of the battery bank has been designed and exemplified to improve the performance of the electrolyzer. The evaluations resulting from this case study may have a genuine value, therefore assisting in further studies to better understand these devices and their associated technologies

Hydrogen and renewable energy sources integrated system for greenhouse heating

The environmental impact and the cost of fossil fuel system for greenhouse heating are the major limits for the development of protected horticulture. Recent researches are focusing on greenhouses optimal climate control and reduction of energy consumption. The use of suitable microclimate control systems, energy efficiency strategies and renewable energy sources could improve the environmental performance of the greenhouses. Renewable energy sources can be used to produce hydrogen by electrolysis with very high gas purity. Hydrogen can serve the purpose of storing overproduced energy after meeting the requirements of the greenhouse, and later it can be employed as fuel, achieving a stand-alone power system. Therefore a research is under development at the University of Bari in order to investigate the suitable solutions of a power system based on solar energy (photovoltaic) and hydrogen, integrated with a geothermal heat pump for powering a self sustained heated greenhouse. The tests were carried out at the experimental farm of the University of Bari sited in Valenzano, Bari, Southern Italy, latitude 41° N, where two experimental greenhouses, with the same geometric and constructive characteristics, have been realized; the distance between the two greenhouses is 12 m; therefore there is no mutual shading. One of the two greenhouses is heated using a low enthalpy heat pump combined with a vertical ground heat exchanger, in comparison with the other unheated greenhouse. The electrical energy for heat pump operation is provided by a purpose-built array of solar photovoltaic modules, which supplies also a water electrolyser system controlled by embedded pc; the generated dry hydrogen gas is conserved in suitable pressured storage tank. The hydrogen is used to produce electricity in a fuel cell in order to meet the above mentioned heat pump power demand when the photovoltaic system is inactive during winter night-time or the solar radiation level is insufficient to meet the electrical demand of the heat pump during overcast cold sky. This note reports the main elements regarding the integrated system design and building and it shows preliminary results of testing operation

Evaluation of coloured nets in peach protected cultivation

The aim of this paper is to investigate the influence of the radiometric properties of coloured nets on peach tree photomorphogenesis. The modification of the spectral distribution of the transmitted radiation and thus the effects on the tree vegetative and productive activity were studied. A field experimental test using coloured nets for the protection of peach trees was carried out during 2008 at the experimental farm of the University of Bari, latitude 41° 05' N. A blue net and a red net, characterised by a nominal shading factor of 40%, and a neutral net with a nominal 12% shading factor were tested. Peach trees in open field conditions were used as control. The effects of the nets on the trees growth were correlated with the radiometric properties of the nets, which were evaluated by means of laboratory tests. The red and blue nets influenced mainly the B/FR ratio: the former net decreased and the latter increased the B/FR ratio. The nets influenced the quantity as the quality of the yield. The red net increased the shoot growth of the trees more than the blue one. The nets influenced positively the fruit weight and skin colour in comparison to the open-field

Contamination of the Environmental Matrices in Agricultural Areas Produced by Industrial Discharges: The Case Study of the Land of the City of Statte (Taranto, Southern Italy)

The diffusion of pollutants in the atmosphere, agricultural soil, irrigation water, crops and food chain can produce potential environmental health risk. The aims of this study are the environmental risk assessment for the aquifers and the estimation of pollutants concentration in the forage for evaluating the risk for human health. The risk analysis was applied in the rural territory of Statte (Taranto, Italy) using an innovative methodology based on the integration of models for estimation of pollutant leaching in the groundwater and for the evaluation of bio-transfer of pollutant in the plant. The model results are in accordance with the experimental values and therefore the proposed methodology allows the evaluation and management of environmental health risks in agricultural areas interested by pollution phenomena generated by industrial plants