1,721,163 research outputs found
Renormalized photon propagator in quantum electrodynamics of plasmonic cavities
Full text linkCavity quantum electrodynamics (cQED) is a captivating field of optical physics that explores the interactions between light and matter and is particularly fascinating in the field of ultrastrong coupling. First, considering the hybridization of electromagnetic cavity (EC) modes and surface plasmon polaritons (SPPs) in a resonant cavity, we show that classical Lagrangian electrodynamics and cQED lead to the same expressions for frequency dispersion when mode dissipation and system-bath interactions are neglected. We then expand the photon propagator to a Dyson series and derive a novel non-perturbative expression for the frequency dispersion of the hybrid modes, which is equivalent to the cQED result but has a richer content. In this context, it is shown that the SPP self-interaction generates a positive self-energy that renormalizes the hybrid SPP-EC eigenfrequencies and is responsible for the well-known blue-shift of the hybrid modes, an aspect that was previously hidden in the known expressions for frequency dispersion
Application of a precision apiculture system to monitor honey daily production
Full text linkPrecision beekeeping or precision apiculture is an apiary management strategy based on the monitoring of individual bee colonies to minimize resource consumption and maximize the productivity of bees. Bees play a fundamental role in ensuring pollination; they can also be considered as indicators of the state of pollution and are used as bio monitors. Beekeeping needs continuous monitoring of the animals and can benefit from advanced intelligent ambiance technologies. The aim of this study was the design of a precision apiculture system (PAS) platform for monitoring and controlling the following environmental parameters: wind, temperature, and relative humidity inside and outside the hive, in order to assess their influence on honey production. PAS is based on an Arduino board with an Atmel microcontroller, and the connection of a load cell for recording the weight of the hive, relative humidity and temperature sensor inside the hive, and relative humidity and temperature sensor outside the hive using an anemometer. PAS was installed in common hives and placed in an open field in a French honeysuckle plot; the system was developed to operate in continuous mode, monitoring the period of 24 April–1 June 2019. Temperature was constant in the monitored period, around 35◦ C, inside the hive, proving that no criticalities occurred regarding swarming or absconding. In the period between 24 and 28 May, a lack of honey production was recorded, attributed to a lowering of the external temperature. PAS was useful to point out the eventual reduction in honey production due to wind; several peaks of windiness exceeding 5 m s−1 were recorded, noting that honey production decreases with the peaks in wind. Therefore, the data recorded by PAS platform provided a valid decisional support to the operator. It can be implemented by inserting additional sensors for detecting other parameters, such as rain or sound
Olive Tree Canopy Assessment Based on UAV Multispectral Images
No full textUnmanned Aerial Vehicle (UAV) is widely used to acquire data on the biometric and spectral characteristics of olive trees through multispectral cameras. Several flight parameters and image processing techniques can be applied in order to obtain this information. The aim of this work was to study the variability of the main biometric parameters and multispectral characteristics of olive trees through multispectral images acquired from a remote platform (UAV) at three different flight altitudes (30, 50 and 70 m), in two acquisition periods, with and without the use of differential coordinate correction (RTK), also applying different image segmentation techniques. Phantom 4 Multispectral UAV platform was used for the two flight campaigns. The photogrammetric processing was carried out using the software Agisoft Photoscan Professional, version 1.7.3. The biometric and multispectral data extraction processing was carried out through the software QGIS, version 3.2. Different segmentation techniques were applied on the acquired images, starting from the main vegetation indices maps as Normalized Difference Vegetation Index (NDVI) and the Modified Soil Adjust Index (MSAVI). The results showed that the olive tree canopy can be accurately studied using the canopy spectral information obtained by the UAV multispectral system
The MAGIC Project: A Tool for Promoting Safety in Agriculture During COVID-19 Pandemic
Full text linkCOVID-19 pandemic poses a threat to global health highlighting the importance of prevention and measures of social distancing. In agriculture, cultivation operations carried out in open field by farm workers represent a serious danger in this sense. Social distancing of the workers during the labor day is not always easy to be maintained, especially for the very close rows among the plants. In 2020, the researchers of the Mechanics Section of the Department of Agricultural, Food and Forest Sciences in collaboration with the Department of Engineering of the University of Palermo, presented a project entitled “Design of a real time Monitoring and control system for AGrIcultural workers to limit the SARS-Cov-2 virus” (acronym MAGIC) to the Italian Ministry of University and Research. The aim of the project was the design of a real time monitoring and control system for workers in agriculture in order to monitor, record and control any violations of the distance among the workers. The system is based on the use of a small device equipped with a uniquely stored serial number that securely emits an alarm signal to both the worker and the manager when the distance between two employees is below the permitted threshold. A central manager perform a historical “track” that lists all the subjects with whom a person has come into close contact. The system was tested at a farm in Sicily during winter pruning in vineyard
Assessment of Vine and Cover Crop Vegetation Indices Using High-Resolution Images Acquired by UAV Platform
No full textIn recent years, there has been an increasing need to implement sustainability in agricultural systems, especially for the risks associated with soil degradation. Cover crops are widely recognised and adopted for sustainable vineyard management, reducing soil and water losses, restoring organic matter, and increasing soil fertility. Therefore, it is necessary to determine the biomass development of cover crops using alternative and innovative methods. High-resolution UAV-based (Unmanned Aerial Vehicle) multispectral images can be used for this purpose, giving significant information for monitoring the seasonal growth variation of crops. The aim of this research was to study the biomass vigour spatial variability of cover crops and vineyard evaluating the possible correlation between cover crop and vineyard vigour values. Cover crop biomass was monitored by sampling during flowering, measuring fresh weight and dry weight. The multispectral images were obtained with the use of a UAV before cover crops were buried (March); the spectral response of the vineyard was evaluated with UAV flights during the summer period. The analysis of the vigour maps obtained showed a degree of variability for the vegetation index examined. This variability was found both on the cover crop biomass development and on the vegetative growth of the vineyard. The results showed the applicability of remote sensing to monitor cover crop and vineyard biomass development, explaining the overall variability of the field. This information allows the application of the appropriate agronomic techniques to improve the quality of the production
Evaluation of Different Flight Courses with UAV in Vineyard
No full textPrecision farming has consolidated the use of Unmanned Aerial Vehicles (UAVs), which have confirmed their role as excellent tools for data acquisition and analysis. These systems have wide operational flexibility, good flight autonomy and excellent spatial resolution of multispectral images. They proved to be more competitive in data acquisition than satellite systems, especially on small areas typical of Italian viticulture. Unfortunately, there is little knowledge in literature about the flight course influence in the extraction of canopy spectral and biometric information. The aim of this work is to compare the different flight directions that can be performed with UAVs, to assess the differences in the acquisition of the spectral response of vineyard canopy and biometric characteristics. The vineyard is located in Camporeale, (Sicily, Italy); with a typical cultivar (Catarratto). The surface area of the experimentation field is 3.2 ha. Row orientation is NE-SW; the field can be divided into two different orographic area. In specific, one of them is flat and the other is hillside with medium-hight slope. Remote images were acquired with a multirotor UAV, equipped with a camera with six multispectral bands, the RGB for visible light images and five monochrome narrow bands for multispectral images. The sensor has a field of view (FOV) of 62.7° and 90° downwards. Front and side over-lapping were 70%. Two flight courses were carried out, one perpendicular and the other parallel to the orientation of the rows. The results show differences in the reconstructions image that induced a variability in multispectral data
Assessment of ranges of rest postures of human lower limbs
No full textBACKGROUND: Several comfort perception models have proposed an objective method to evaluate 'effects in the internal body' and 'perceived comfort'. Postural comfort is one aspect of comfort/discomfort perception, and this current work adds to existing knowledge toward a more objectified posture evaluation for comfort. OBJECTIVE: The authors have used the concept of Range of Rest Posture (RRP), as proposed by Apostolico et al. The study focused on the identification of RRP within the Comfort Range of Motion (CROM) for lower limbs. METHODS: The proposed method is based on extensive experimental work involving 114 healthy individuals (59 males and 55 females) ranging from 20 to 40 years old. The age range was narrowed to avoid an age-clustering of results due to inhomogeneity of the statistical sample. Data were processed using statistical methods for identifying the RRP in the experimental CROM. Several Maximum Level of Comfort (MLC) positions were found within the RRP. RESULTS: RRPs for lower limbs of men and women have been identified and can be used for virtual comfort assessment. CONCLUSIONS: This paper shows a method to evaluate in a more objective way the subjective postural comfort perception and results allow researchers to improve models for the virtual preventive comfort assessment
Messa in opera di un vigneto con sistema GPS e tradizionale
Full text linkLa progettazione del nuovo vigneto non può prescindere oggi da una attenta analisi non solo del sito ma anche dei materiali che saranno impiegati per la realizzazione della struttura portante della vegetazione. La tecnoloigia Gps applicata alla messa in opera dei pali per la preparazione di un vigneto
a controspalliera ha permesso di ottenere un impianto preciso anche in presenza di terreni in pendenza, con una minore usura degli scuotitori,
assenza di rottura dei pali e tempestività di intervento
Implementation of an innovative technique to improve Sauvignon Blanc wine quality
No full textThe purpose of the study was to compare two different pressing systems of Sauvignon Blanc grapes using an innovative wine press manufactured by Puleo Srl Company (Marsala, Italy). Grape pressing is a very important step in the winemaking process as it may promote the presence and/or absence of enzyme processes on the must, leading to the creation of different products in terms of chemical composition from the same grapes. Chemical composition of must firstly and wine after, obtained from the two pressing mode, was analysed in first instance with PCA method
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