133 research outputs found
Sermoni liturgici
No full textIntroduzione e testo a cura di Mauro Todde. Revisione critica e commento a cura di Gabriele Pelizzari. Nel commento ai Sermoni cromaziani Gabriele Pelizzari ha tentato di porre in evidenza i presupposti teologici, la tecnica ermeneutica e lo stile omiletico del vescovo aquileiese.
Tramite l'analisi di questi documenti è stato possibile porre in evidenza la forte cifra giudeo-cristiana della teologia cromaziana; soprattutto, tramite la sottolineatura di alcuni teologumeni ricorrenti e del ricorso preferenziale a tecniche esegetiche di chiaro stampo tipologico, è stato possibile restituire la predicazione di Cromazio al suo Sitz im Leben storico, entro il quale il pardigma cristiano professato nell'Aquileia di fine IV secolo assunse spiccati caratteri di originalità e autonomia
Prefazione
No full textIl volume contiene la guida ai fondi dell'Archivio storico dell'Università di Cagliari, a seguito del riordino condotto da M. Rapetti e E. Todde, sotto la supervisione scientifica di C. tasca (responsabile scientifico)
“Una miniera di carte”: guida alle fonti per lo studio dell’attività estrattiva in Sardegna
No full textThis paper aims at drawing up a short guide to sources on the mining industry in Sardinia. This article aims to draw up a short guide to sources on the mining industry in Sardinia.
The author, after a presentation of the main points regarding the history of the mining sector and the consequent sedimentation of the documentary complexes of private companies and state organizations, proposes archival records divided by conservation institutes in which to find access information, the types of documents, the means of equipment available to users and the bibliography. There is also an overview of the information systems currently on the web where you can find the thematic portals, institutional sites and the sisma portal (Historical Information System Mining Archives) created by the University of Cagliari
Influence of the milking units on the pulsation curve in dairy sheep milking
No full textMechanical milking is a critical operation in ewe dairy farming where the operative parameters and the milking routine strongly influence milk production and animal welfare. The challenge in adapting dairy animals to the farm environmental conditions may cause illness and compromise the quality of the products. From this perspective, it is important to evaluate the technological and operational aspects that can influence milk quality and animal welfare. Thus, the aim of this work was to investigate the effects on the pulsation curve of several teat cup characteristics (volume of the pulsation chamber) at determined operating parameters (vacuum level and pulsator rate) recorded from nine different milking units. Moreover, the touch point pressure of different liners was measured. Data analysis showed that the sheep milking unit characteristics affected the pulsation curve significantly. The length of both the increasing vacuum phase and the decreasing vacuum phase (phase “a” and “c”, respectively), which affect the milking and massage phases, was directly related to the pulsation chamber volume (R2 = 0.86) and the pulsator rate. No relationship emerged between the touch point pressure and specific characteristics of the liners such as the material, the shape, the diameter, the length, or the extension of the body. Considering the delicate role that the pulsation plays in ensuring animal welfare during milking, it is important to take into account the complete configuration and operative characteristics of the milking units. This will ensure that the complex interaction between the pulsation system and the milking units is considered when planning and assembling milking systems
Evaluating an autonomous electric robot for real farming applications
No full textMobile robotic technologies are emerging in agriculture in recent years, driven by labor shortages, the need of precision farm management, and the improvement of farmers' quality of life. Mobile robotic technologies, both aerial and ground, have been considered as one of the most important and promising solutions to address agricultural challenges. Nevertheless, the implementation rate in farms is still low. The aim of this study was to evaluate the performance of a mobile agricultural ground robot to assess its possible implementation in the farm environment. The mobility performances as well as the energy consumption of the mobile robot were evaluated considering different interaction systems (teleoperated, autonomous driving) and application areas (weeding, tilling). The results show that the forward speed of the tested mobile robot is affected by the towed load, up to 230 kg, and that the robot could be driven continuously for 2 h in the field without decreasing its performances at a maximum speed between 0.71-0.77 m s-1. The autonomy of the tested robot is limited, but this is mainly due to the battery technology used. The mobile robot effectively tow implements for weeding and tilling operations managing grass with a single pass (40 % weed removal) and improving soil bulk density. The average energy consumption across the different settings was about 1.43 kWh for each hour of use. Moreover, although the RTKGNSS autonomous navigation used was a low-cost system, the results showed a good accuracy, which allowed the mobile robot to navigate autonomously in the 2 m inter-row of the vineyard. Finally, the working capacity of the mobile robots, considering the implements used, is on average 0.29 ha h-1. This study provides further evidence for the possible use of ground mobile robot in agriculture to carry out autonomous or semi-autonomous operations
Experimental Analysis of Low-Reynolds number Free Jets - Evolution along the jet centerline and Reynolds number effects
No full textThe present paper analyzes the features of a low-Reynolds number free submerged jet with special regard to statistical quantities on the jet centerline. Measurements in an environment with very low disturbances allowed to observe details of turbulence and higher-order moments. Some peculiar features of the measured (natural) jet are shown to be in correspondence to observations referring to forced higher-Reynolds number jets. In particular, it is shown that, at low Reynolds numbers, the initial region of the jet is dominated by well-defined vortices in the shear layer. This result is substantiated by both the statistical moments and the spectral analysis. The presence of two distinct regimes is evidenced and discussed from a physical standpoint, also in relation to the mathematical analysis of the jet structure from the bibliography
Exploring Smart Glasses for Augmented Reality: A Valuable and Integrative Tool in Precision Livestock Farming
No full textThe growing interest in Augmented Reality (AR) systems is becoming increasingly evident in all production sectors. However, to the authors’ knowledge, a literature gap has been found with regard to the application of smart glasses for AR in the agriculture and livestock sector. In fact, this technology allows farmers to manage animal husbandry in line with precision agriculture principles. The aim of this study was to evaluate the performances of an AR head-wearable device as a valuable and integrative tool in precision livestock farming. In this study, the GlassUp F4 Smart Glasses (F4SG) for AR were explored. Laboratory and farm tests were performed to evaluate the implementation of this new technology in livestock farms. The results highlighted several advantages of F4SG applications in farm activities. The clear and fast readability of the information related to a single issue, combined with the large number of readings that SG performed, allowed F4SG adoption even in large farms. In addition, the 7 h of battery life and the good quality of audio-video features highlighted their valuable attitude in remote assistance, supporting farmers on the field. Nevertheless, other studies are required to provide more findings for future development of software applications specifically designed for agricultural purposes
Temporary intercropping of cultivated cardoon in Mediterranean mountain farmlands: A case study from Gennargentu-Mandrolisai (Sardinia, Italy)
No full textCultivated cardoon (Cynara cardunculus L. var. altilis DC.) is a versatile crop used both for food and energy production that could play a role in the integrated agro-pastoral systems of Mediterranean mountains. This 3-year experiment focused on I) verifying the adaptability of this crop to mountain environmental conditions and II) testing cultivated cardoon temporary intercropping, during its first year of cultivation, with two forage species as a strategy for weed control and for providing additional fodder production. Two intercropping treatments were considered: cultivated cardoon intercropped with fodder radish (Raphanus sativus var. oleiformis Pers) - FR; cultivated cardoon intercropped with serradella (Ornitopus sativus Brot.) – SR and a control treatment with cultivated cardoon without intercropping – NC. Cultivated cardoon well survived the harsh climatic conditions of Mediterranean mountain areas, even characterised by snow events during the first year of cultivation. Temporary intercropping affected the cultivated cardoon plant density, its height and yield components. After three years from sowing, the legacy effect of intercropping was still evident. Already at the beginning of the second year, in the plots where cultivated cardoon was formerly intercropped with fodder radish, the cultivated cardoon density was significantly higher than under the other two treatments (6.8 plants m-2 vs 2.1 - 2.2 plant m-2). The temporary intercropping contributed on average to a dry matter production of 209 g m-2 ( ± 18.2 g m-2 standard error - SE) for fodder radish and 317 g m-2 ( ± 40.1 g m-2 SE) for serradella. The cultivated cardoon achene yield in the 3 rd year was significantly higher in plots under FR treatment (2.73 t ha-1) than in those under SR treatment (0.90 t ha-1) and NC (0.37 t ha-1). A significantly higher presence of Poaceae weeds was observed when cultivated cardoon was under SR treatment
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