1,721,085 research outputs found
Simulazione mediante modello matematico della solarizzazione con doppio strato di film plastico
No full textNUMERICAL SIMULATION MODEL FOR SOLARIZATION WITH DOUBLE PLASTIC FILM
A mathematical model describing the energy balance in the soil mulched with a double photodegradable plastic film structure was developed. The model was implemented on a PC in order to predict the soil temperature under the mulching materials at different soil depths as a function of the solar radiation, the external temperature and the wind velocity. Experimental tests were carried out for testing the model by means of measured figures. Particularly the climatic parameters and the soil temperature at the depths of 10, 20, 30 and 50 cm in a solarized and in a uncovered non solarized soil were measured during the testing period in July and August of 1993. The comparison between the measured and the calculated data, obtained by the simulation model, showed a good agreement between them.
The effects produced by the solarization with the double film structure on the soilborn pathogens and on the weed natural infestation in the mulched soil were analysed. The thermal levels reached in the solarized soil were able to reduce strongly the soilborn pathogens and the weed natural infestation in comparison with the uncovered soil
Collapse full scale test on a stell greenhouse tunnel structure
No full textConvegno tenutosi a Vieste, Ital
Sistema autoadattativo di controllo per serre
No full textSELF-ADAPTIVE CONTROL SYSTEM FOR GREENHOUSES
Aim of the research is the development of a self-adaptive control system of the greenhouse air temperature. Experimental tests have been carried out in two greenhouses comparing the self-adaptive with an on/off system. The tests have showed a higher capacity, for the self-adaptive compared with the on/off system, in maintaining the set-point value and energy savings of about 3%.Obiettivo del lavoro è lo sviluppo di un sistema di controllo autoadattativo della temperatura dell'aria interna di serre riscaldate, o fredde con impianto di riscaldamento di soccorso. A tale scopo sono state condotte prove sperimentali di comparazione tra un sistema autoadattativo e un sistema on/off su due serre sperimentali. I risultati delle prove hanno mostrato una maggiore capacità del sistema autoadattativo nel mantenere il valore di set-point, congiuntamente a risparmi energetici di circa il 3%.SELF-ADAPTIVE CONTROL SYSTEM FOR GREENHOUSES
Aim of the research is the development of a self-adaptive control system of the greenhouse air temperature. Experimental tests have been carried out in two greenhouses comparing the self-adaptive with an on/off system. The tests have showed a higher capacity, for the self-adaptive compared with the on/off system, in maintaining the set-point value and energy savings of about 3%
Preparation and Performance of Novel Biodegradable Polymeric Materials Based on Hydrolyzed Proteins for Agricultural Application
No full textAim of the research is the development of biodegradable polymeric materials based on hydrolyzed proteins,
derived from waste products of the leather industry. Particular attention has been devoted to evaluate the application of
such biobased materials in the agricultural practice of mulching. Biobased mulching films were generated in situ by lowpressure
spraying of polymeric water dispersion on the soil; the mulches were tested in an ornamental cultivation carried
out inside a greenhouse. The innovative spray films based on biodegradable components lasted in the field up to 12
months, keeping their mulching effect, thus guarantying weed suppression and preserving soil aggregates
Effects of vertical green technology on building surface temperature
Full text linkA sustainable technology for improving the energy efficiency of buildings is the use of urban greening in order to reduce the energy consumption for air conditioning in summer and to increase the thermal insulation in winter. A worldwide growing interest in urban green is encouraging the application of the greening technology for more sustainable buildings. Building indoor air temperature depends on several different parameters related to the climate of the region, the building itself and its use. The main parameters influencing the microclimate are: external air temperature and relative humidity, incident solar radiation, long wave radiation exchange between the building surfaces and its surroundings, wind velocity and direction, air exchanges, physical and thermal properties of the building's envelope materials, design variables such as building dimensions and orientation, presence of artificial light, electrical equipment. Green façades can allow the physical shading of the building and promote evapotranspiration in summer and increase the thermal insulation in winter. External wall surface temperature is a parameter useful to assess the effectiveness of green façades. An experimental test was carried out at the University of Bari (Italy) for three years. Three vertical walls, made with perforated bricks, were tested: two were covered with evergreen plants (Pandorea jasminoides variegated and Rhyncospermum jasminoides) while the third wall was kept uncovered and used as control. Several climatic parameters concerning the walls and the ambient conditions were collected during the experimental test. The experimental data were used for developing a multiple regression equation regarding the dependence of the difference of external surface temperature between the green façades and the control wall and the weather conditions. The model shows a good predicting ability
Predictive model of surface temperature difference between green façades and uncovered wall in Mediterranean climatic area
Full text linkThe thermal potential of vertical greenery systems in buildings can be fully explored through modelling. Models
support designers in choosing between different technical solutions. This study analyses the cooling effect of two
plants suitable for the Mediterranean area. A regression model simulating the difference of the wall external
surface temperature between the wall covered with vegetation and an uncovered wall was developed. In order to
overcome the gaps in literature, the model was fitted and validated on long period experimental data. It was
based only on the use of climatic conditions as input variables, without making assumptions about the plants.
Climatic data were grouped in solar radiation slots; the most significant predictors were selected for each slot.
The adoption of this method allowed to obtain, during validation, coefficients of determination (R2) higher than
0.95 and low values of the root mean square error (0.4–0.6 °C). It was found that the vegetated walls recorded
surface temperatures lower than the uncovered wall up to 7.7 °C in summertime. The results showed that the
model developed with a statistical approach can efficiently be used for simulating the thermal effects of a green
façade in a similar Mediterranean climate
– Natural ventilation as a management tool for the optimisation of greenhouse operation control
No full textXXX Convegno Internazionale CIOSTA - CIGR V, Torino (Italia
Indoor vertical greening for regulating building microclimate
No full textThe integration of vegetation in buildings can increase the environmental sustainability of urban
contexts as well as produce other relevant unquantifiable effects. Vegetation can be applied both on the
exterior side of the buildings’ envelope and inside, in different ways and layouts. Green façades are a
specific kind of vertical greening for buildings consisting of plants covering vertical walls of buildings. The
presence of vegetation on the envelope positively affects the building’s thermal and acoustic performance,
air quality, aesthetics, with relevant consequences in terms of energy and cost savings and human wellbeing. Until now, research has focused mainly on vertical greening systems applied to the exterior side of
the buildings, but indoor applications deserve attention as well. This is the reason behind the present
research: assessing the physical functioning of an indoor green façade. To this end, an experimental
prototype of an indoor greening system was designed and realized to be monitored, at the University of
Bari. The prototype consists of a sealed chamber, with evergreen plants, properly equipped with sensors for
collecting air, soil and plant parameters, needed for studying the system functioning. The database created
with the collected data enables investigations of the green façade behaviour and effects. A better
understanding of this green technology, allowing for informed design and knowledge of induced effects,
can promote the spread of indoor green façades
Green façades to control wall surface temperature in buildings
No full textGreen façades can represent a sustainable solution for construction of new buildings and for retrofitting of existing buildings, in order to reduce the energy demands of the cooling systems, to mitigate the urban heat island and to improve the thermal energy performance of buildings. Green façades can allow the physical shading of the building and promote evapotranspiration in summer, and increase the thermal insulation in winter. An experimental test was carried out at the University of Bari (Italy) for two years. Three vertical walls, made with perforated bricks, were tested: two were covered with evergreen plants (Pandorea jasminoides variegated and Rhyncospermum jasminoides) while the third wall was kept uncovered and used as control. Several climatic parameters concerning the walls and the ambient conditions were collected during the experimental test. The daylight temperatures observed on the shielded walls during warm days were lower than the respective temperatures of the uncovered wall up to 9.0 °C. The nighttime temperatures during the cold days for the vegetated walls were higher than the respective temperatures of the control wall up to 3.5 °C. The thermal effects of the facades at daytime was driven by solar radiation, wind velocity and air relative humidity. The highest cooling effect of such parameters occurred with a wind speed of 3–4 ms−1, an air relative humidity within the range 30–60% and a solar radiation higher than 800 Wm−2. The long-term experimental test demonstrated that both Pandorea jasminoides variegated and Rhyncospermum jasminoides are suitable for green façades in the Mediterranean climatic area. The results shown in the present research allow to fill the gap in literature concerning the lack of data for all the seasons of the year, in order to obtain a complete picture of the building thermal performance in the Mediterranean climate region
Heat transfer mechanisms in vertical green systems and energy balance equations
Full text linkThe use of vegetated vertical systems is a sustainable technology for improving the energy efficiency of buildings in cities in order to reduce the energy consumption for air conditioning in summer and to increase the thermal insulation in winter. increasing urban green infrastructure (ugi) in a city can contribute to improve urban climate in summer reducing buildings surface temperature and urban air especially in southern europe. the application of vertical green systems requires the knowledge of the energy performance of the applied greenery system. the choice of the green facades depends on the local climate, water availability, building shape. the presence of green facades affects the building microclimate all day, by reducing heat waves during the warm periods and heat losses from the building in the cold period. the heat and mass transfer between the external environment, the green facades and the building surface determine the building microclimate. solar radiation, long wave infrared radiation, convective heat transfer and evapotranspiration are the main mechanisms of heat transfer in a green façade. the paper describes the main parameters concerning heat flow in green facades that can be used in simulation models for predicting temperatures in buildings using the external weather conditions as model inputs. the input parameters are: external air temperature and relative humidity, solar radiation, wind velocity and direction, plants and building characteristics. the green facade was described by a schematic representation, four layers were defined: the green layer, the external surface of the building wall, the internal surface of the building wall, the air inside the building. the energy balance was defined for each layer and all the terms involved in the energy exchange between the layers were defined as a function of the plant, the weather conditions and the constructive characteristics of the wall
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