818 research outputs found
Seismic Analysis of Traditional Stone Rural Buildings: Case study of a one-storey building
Specific features of traditional rural buildings can influence the assessment of their seismic behaviour. When a change in intended use of traditional rural buildings is necessary, restoration work must comply with specific seismic norms and should preserve their original features. In this paper, a model for the seismic safety verification of masonry walls for inplane actions was applied to investigate the structural behaviour of one-storey stone-masonry traditional rural buildings, in relation to standards application and possible retrofitting interventions. The results showed that pier-panel collapse mechanisms and the simulation method of masonry spandrel behaviour are of importance and affect the need to provide for strengthening interventions
Potential biogas production from agricultural by-products in Sicily. A case study of citrus pulp and olive pomace
Renewable energy sources represent a suitable alternative to conventional fossil fuels, due to the possible advantages in terms of environmental impact reduction. Anaerobic digestion of biomasses could be considered an environmental friendly way to treat and revalorise large amounts of by-products from farming industries because it ensures both pollution control and energy recovery. Therefore, the objective of this study was to define a methodology for evaluating the potential biogas production available from citrus pulp and olive pomace, which are suitable agricultural by-products for biogas production. In the first phase of the study, the spatial distribution of both olive and citrus-producing areas was analysed in Sicily, a geographical area of the Mediterranean basin highly representative of these types of cultivation. Then, a GIS-based model, which had been previously defined and utilised to evaluate the amount of citrus pulp and olive pomace production, was applied to this case study. Based on the results obtained for the different provinces of Sicily, the province of Catania was chosen as the study area of this work since it showed the highest production of both citrus pulp and olive pomace. Therefore, a further analysis regarded the quantification of olive pomace and citrus pulp at municipal level. The results of this analysis showed that the total amount of available citrus pulp and olive pomace corresponded theoretically to about 11,102,469 Nm3/year biogas. Finally, the methodology adopted in this study made it possible to identify suitable areas for the development of new biogas plants by considering both the spatial distribution of the olive and citrus growing areas and the locations of the existing processing industries
Assessing influence factors on daily ammonia and greenhouse gas concentrations from an open-sided cubicle barn in hot mediterranean climate
Measurement of gas concentrations constitutes basic knowledge for the computation of emissions from livestock buildings. Although it is well known that hot climate conditions increase gas emissions, in the literature the relation between gas concentrations from open barns and animalrelated parameters has not been investigated yet. This study aimed at filling this gap by evaluating daily gas concentrations within an open-sided barn in hot Mediterranean climate. The influence of microclimatic parameters (MC) and cow behavior and barn management (CBBM) were evaluated for ammonia (NH3 ), methane (CH4 ), and carbon dioxide (CO2 ) concentrations. Results showed that both MC and CBBM affected concentrations of NH3 (p < 0.02), CH4 (p < 0.001), and CO2 (p < 0.001). Higher values of NH3 concentration were detected during the cleaning of the floor by a tractor with scraper, whereas the lowest NH3 concentrations were recorded during animal lying behavior. Measured values of CO2 and CH4 were highly correlated (C = 0.87–0.89) due to the same sources of production (i.e., digestion and respiration). The different management of the cooling systems during the two observation periods reduced significantly CH4 concentrations in the barn when the cooling system in the feeding area was switched off. Based on methodological choices due to the specific barn typology, parameters related to animals can provide information on the variation of gas concentrations in the barn environment in hot climate conditions
ACLAS – a method to define geologically significant lineaments from potential fields data
Geological features, such as faults, dikes and contacts appear as lineaments in gravity and magnetic data. The Automated Coherent Lineament Analysis and Selection (ACLAS) method is a new approach to automatically compare and combine sets of lineaments or edges derived from two or more existing enhancement techniques applied to the same gravity or magnetic data set. ACLAS can be applied to the results of any edge detection algorithms and overcomes discrepancies between techniques to generate a coherent set of detected lineaments, which can be more reliably incorporated into geological interpretation. We demonstrate that the method increases spatial accuracy, removes artefacts not related to real edges, increases stability and that it is fast to implement and execute. The direction of lower density or susceptibility can also be automatically determined representing, for example, the downthrown side of a fault. Here, ACLAS is demonstrated on magnetic anomalies calculated from a simple slab model and from a synthetic continental margin model with noise added to the result. The approach helps to identify and discount artefacts of the different techniques, although the success of the combination is limited by the appropriateness of the individual techniques and their inherent assumptions. ACLAS has been applied separately to gravity and magnetic data from the NW Australia shelf displaying results from the two data sets together helps the appreciation of similarities and differences between gravity and magnetic results and indicates the application of the new approach to large scale structural mapping. Future developments could include refinement of depth estimates for ACLAS lineaments
Development of an information system for the traceability of citrus-plant nursery chain related to the Italian National Service for Voluntary Certification
Abstract: At present, the production of certified plants in Italy, which is obtained by using propagating materials verified in terms of varietal trueness-to-type and phytosanitary condition, is guaranteed by the National Service for Voluntary Certification. The monitoring of productions and activities that are carried out in the centres established by the National Service for Voluntary Certification is crucial for the identification of both possible sources of disease risk and the destination of the propagating materials. In previous studies a methodology was proposed and applied to carry out the requirements analysis and specification for the development of an integrated computer-based information system for certified citrus-plant traceability. This study proposes a methodology for the implementation of the information system suitable to execute the previously designed functionalities. The use of PostgreSQL, a free and open-source object-relational database management system, allowed the implementation of the entity-relation scheme that included the information related to the managed propagating materials and the process activities defined by the certification program. System functionalities were implemented in applications developed on the basis of the client-server paradigm. The proposed methodology was applied to the case study of the Italian citrus-plant nursery chain. Specific information derived from plants and centres of the National Service for Voluntary Certification were included in the database along with the geolocation of both certified citrus plants produced in the nurseries and planted in the field and citrus mother plants. Geographic data acquired by using a GPS system were combined with other information concerning plant health condition and treatments with the aim to find out possible relations between the citrus-plant health status and the territory. The system implemented in this study allows the definition and utilisation of ‘track and trace’ procedures of propagation materials and plants that are in the certified Italian citrus-plant nursery chain, as well as the evaluation and prevention of the diffusion of the Citrus Tristeza Virus which causes one of the most damaging diseases in citrus orchards. Keywords: citrus, certification, traceability, nursery chain, GIS, information system, plant disease
Improving natural ventilation in renovated free-stall barns for dairy cows: Optimized building solutions by using a validated computational fluid dynamics model
Natural ventilation is the most used system to create suitable conditions, removing gases, introducing oxygen in livestock buildings. Its efficiency depends on several factors and above all on the number, the dimensions and the position of wall openings and internal layout of livestock buildings. The aim of this research was to develop optimized layout solutions for improving natural ventilation effectiveness in free-stall barns for dairy cows by using a CFD approach. A validated computational fluid dynamics (CFD) model was applied in a case study which is highly representative of building interventions for renovating the layout of free-stall barns for dairy cows located in an area of the Mediterranean basin. Firstly, dairy cow behaviour was analysed by visual examination of time-lapse video-recordings. Then, simulations were carried out by using the validated CFD model and changing the position of internal and external building elements (i.e., internal office and external buildings for milking) in order to find the best condition for the thermal comfort of the animals. The results showed that the best conditions were recorded for a new configuration of the building in terms of air velocity distribution within the resting area, the service alley and the feeding alley for dairy cows, and in the pens for calves. In this new layout, the office areas and the north-west wall openings were located by mirroring them along the transversal axis of the barn. Therefore, the CFD approach proposed in this study could be used during the design phase, as a decision support system aimed at improving the natural ventilation within the barn
Development of a CFD model to simulate natural ventilation in a semi-open free-stall barn for dairy cows
Natural ventilation is the most common passive cooling system in livestock buildings. The aim of this research is to assess airflow distribution inside a free-stall barn for dairy cows by computational fluid dynamics (CFD) modelling and simulation. The model is validated by using the average values of experimental data acquired in a free-stall barn, which is considered relevant because it is located in a region characterised by hot climate conditions during the summer that could induce animal heat stress. Simulations are carried out in steady-state conditions, and simulated data are validated by the average values of air velocity measurements. Since the modelled air velocity distribution in the barn fits the real one well, the CFD model is considered reliable to simulate other conditions. The application of the proposed CFD model in the simulation of specific building design alternatives could be aimed at studying the related airflow distribution in order to find the best configuration
Kernel density estimation analyses based on a low power-global positioning system for monitoring environmental issues of grazing cattle
The use of wearable sensors that record animal activity in intensive livestock systems has become more and more frequent for both early detection of diseases and improving production quality. Their application may also be significant in extensive livestock systems, with infrequent farmer-to-animal contact. The pre-sent study aimed to prove the feasibility of a novel automatic sys- tem for locating and tracking cows in extensive livestock systems based on space-time data provided by a low-power global positioning system (LP-GPS). The information was used to study the pasture exploitation by the herd for modelling the environmental impacts of extensive livestock systems through geographical information systems (GIS). A customised device, placed within a rectangular PVC case compatible with the collar usually worn by animals, was equipped with an LP-GPS omnidirectional system, an integrated SigFox communication system, and a power supply. The experimental trial was conducted in an existing semi-natural pasture characterised by good pasture allowance and cultivated grazing areas. Ten cows were embedded with LP-GPS collars, and the data, i.e., geographical coordinates and the time intervals related to each cow detection, were recorded every 20 minutes. Data were collected through a specifically developed AppWeb to be further imported and elaborated by using a GIS software tool. In the GIS environment, the daily distances travelled by each cow were linked with heatmaps obtained by applying Kernel density estimation models from the points obtained from the LP-GPS col-lars. The study results made it possible to obtain information on some relevant aspects of livestock’s environmental issues. In detail, it was possible to acquire information on herd behaviour related to the use of the pasture, e.g., the area of the pasture most frequently used during the day, individual use of the pasture, and possible animal interactions. These results represent the first step towards further insights and research activities because monitoring of animal locations could reduce several environmental issues such as soil degradation and greenhouse emissions. r
Targeting cancer cells overexpressing folate receptors with new terpolymer-based nanocapsules: Toward a novel targeted dna delivery system for cancer therapy
Chemotherapeutics represent the standard treatment for a wide range of cancers. However, these agents also affect healthy cells, thus leading to severe off-target effects. Given the non-selectivity of the commonly used drugs, any increase in the selective tumor tissue uptake would represent a significant improvement in cancer therapy. Recently, the use of gene therapy to completely remove the lesion and avoid the toxicity of chemotherapeutics has become a tendency in oncotherapy. Ideally, the genetic material must be safely transferred from the site of administration to the target cells, without involving healthy tissues. This can be achieved by encapsulating genes into non-viral carriers and modifying their surface with ligands with high selectivity and affinity for a relevant receptor on the target cells. Hence, in this work we evaluate the use of terpolymer-based nanocapsules for the targeted delivery of DNA toward cancer cells. The surface of the nanocapsules is decorated with folic acid to actively target the folate receptors overexpressed on a variety of cancer cells. The nanocapsules demonstrate a good ability of encapsulating and releasing DNA. Moreover, the presence of the targeting moieties on the surface of the nanocapsules favors cell uptake, opening up the possibility of more effective therapies
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