1,721,000 research outputs found
Detection of Astringent and Deastringent Persimmon Fruits using Hyperspectral Imaging Technology
Get PDFPersimmon fruit cv. ‘Rojo Brillante’ is an astringent cultivar due to its content of soluble tannins. Traditionally, the consumption of this cultivar has been only possible when the astringency has been naturally removed before harvest, when fruit is overripe and the manipulation is very delicate. In recent years, new postharvest treatments, which allow astringency removal while preserving high flesh firmness, have been developed. Among them, the most widely used in commercial settings is based on exposing fruits to high CO2 concentrations for 24 h–36 h. This method promotes anaerobic respiration in the fruit, giving rise to an accumulation of acetaldehyde and insolubilizing tannins at the end of the treatment. The effectiveness of this treatment is controlled by means of methods that are destructive, time-consuming and only a few samples per batch can be analysed. For this reason, the objective of this work is to study the application of the hyperspectral imaging technology in the detection of astringent and deastringent fruits non-destructively. A total of 300 fruits were used and exposed to CO2 during different times in order to obtain fruit with different content of soluble tannins. The hyperspectral images of the fruits were acquired using a VIS-NIR hyperspectral system, which covers the spectral range 450-1040 nm. A reference analysis of soluble tannins was performed in order to find out if the fruits were astringent or deastringent. The spectral information of the two thirds of the fruits was used to build the classification models by means of
partial least squares (PLS) and support vector machine (SVM) discriminant analysis methods. The remaining third was used to validate the models as test set. As result, 92.6 % astringent and 84.4 % deastringent fruits were classified correctly using the SVM method. This shows the great potential of hyperspectral imaging technology to detect astringent and deastringent fruits in industrial setups
Preliminary approach for the detection of olive trees infected by Xylella fastidiosa using a field robot and proximal sensing
Get PDFA small field robot was designed and built within the framework of the H2020 project Xylella fastidiosa Active Containment Through a Multidisciplinary-Oriented Research Strategy (XF-ACTORS). The robot is remotely driven and provided with different proximal sensing equipment for the early detection of Xf in olive groves, including thermal, colour and multispectral cameras, and a 2D laser scanner (LiDAR) to obtain the 3D structure of the crop. The equipment is completed by a GPS to geolocate the data obtained and an IMU (inertial measurement unit) to correct the data captured by the LiDAR. An industrial computer triggers the sensors and controls the data acquisition, which is synchronised with the advance of the robot by means of a pulse encoder coupled to the axis of the motor. Then, crop maps can be created off-line after the analysis of the collected data to show graphically potential Xf infection in the trees. Owing to the height of the olive trees inspected, the cameras were placed on a platform that can be elevated up to 200 cm. Two batteries power the electric motors attached to the wheels, thereby allowing a continuous inspection for approximately six hours (a field of about 4 ha). A series of tests have been carried out in an olive orchard showing slight symptoms of Xf infection in the region of Apulia, southern Italy. During the first tests, the robot inspected each row in both directions with the cameras pointing to one side, so as to inspect all sides of the trees. The tests were mainly focused on the development of the mechanics, navigation systems, sensors and data acquisition. Synchronised and geolocated images of the whole crop were also captured with the cameras in different climatic conditions, as well as with the laser scanner for later comparison to the in-situ observation
Analysis of Different Mechanical Pruning Strategies on the Production of 'Clemenules' Mandarin and its Costs
Get PDFSpain is the sixth citrus producer in the world and the first exporter for fresh consumption. However, the
profitability of citriculture is going down due to the increasing production costs and the low prices perceived by farmers. Between farming operations, pruning is done manually, which represent around 12.5% of the total production costs. The objective of this study was to analyse the effect of different mechanical pruning strategies on the production of mandarins variety 'Clemenules' comparing them with manual pruning, and to determine their costs. A trial with a random blocks experimental design with 5 repetitions was carried out in a commercial Clemenules orchard located in Chiva (Valencia). During season 2017, eight pruning strategies were assessed: C (control, no pruning); M (manual pruning, with hand saw and pruning shears); and six mechanical pruning with disc pruner: TEW (Topping, Hedging both sides, East and West), TR (Topping, Manual follow-up), TER (Topping, Hedging Est side, Manual follow-up), TE (Topping, Hedging Est side), EW (Hedging both sides) and E (Hedging Est side). The results of trials showed differences in production and costs between the pruning strategies. C was significantly the most productive with 157 kg/tree; the following more productive were M, EW and E ranging between 128 and 132 kg/tree with no differences between them; and in a third level were all treatments where Topping was carried out (TEW, TE, TER and TR) that oscillate between 72 and 85 kg/tree without significant differences between them. Costs were higher for treatments with manual pruning. Cost for M was 441 €/ha and for the treatments with manual follow-up pruning they oscillated between 459 and 293 €/ha. However, the cost for mechanical pruning ranged between 25 to 110 €/ha depending on the number of machine passes. To get more consistent conclusions, more seasons comparing pruning strategies must be performed
Evaluation of a Citrus Mobile Platform Using a Wireless Impact Recording Device
Get PDFManual citrus harvesting is an expensive operation that represents between 25-40% of the total production
costs. A mobile platform prototype to assist in the harvesting of citrus fruits designed by the IVIA (Spain) has been tested in order to reduce fruit damages. The mobile platform is fitted with conveyor systems. The multilevel platform can accommodate 4 to 8 workers who pick the fruit and place it on a conveyor belt. The picked fruit is transported to a central conveyor belt on which the fruit is transported to the in-line sorting system that classifies the fruit in two categories using a computer vision system and directs the fruit to one of the two different binfillers. During this process the fruits are subjected to mechanical stress causing physical injuries, including skin punctures, pulp and cell rupture. An impact recording device was used to evaluate damage produced to citrus fruits. The critical points at which damage occurs were determined, and the damage levels assessed. The highest damage level was produced from the bin-fillers to the bins. Seven different shocking absorbing materials were tested in order to reduce fruit damage. Five of the seven tested materials were capable to reduce the recorded impact
Field robot to detect plants infected by Candidatus Liberibacter solanacearum in horticultural crops using multispectral computer vision
Get PDFProceedings of AgEng 2018, Wageningen (The Netherlands) 8-11 July 201
Analysis Of Factors Affecting Ammonia And Methane Emissions From Pig Slurries: Slurry Composition And Dietary Factors
Get PDFReducing crude protein is a recommended technique to reduce nitrogen excretion and ammonia emissions. Greenhouse gas emissions from slurry are also affected by nutrient composition. However, there are interactions among nutrients in feeds still not clarified. The objective of this study was to evaluate the impacts of different diets on nitrogen (N) and energy balances. A total of 13 diets were evaluated in digestibility trials using 78 animals.
Diets were formulated to fulfil commercial standards, although differing in ingredient composition. Nutrient
intake, excretion and potential NH3 and CH4 (Biochemical methane potential) emissions from slurry were
measured. Animal weight was also monitored. Correlations between emissions and nutrient balance components were done. An analysis of variance was conducted to assess differences in nutrient balance of low, medium and high emitting animals, expressing animals per kg of live weight increased. For the N balance, a two-fold range in faeces to urine N excretion ratio was found throughout the experiments, even considering the low crude protein variations (from 15 to 16%). This was related to the ammonia emissions from slurry (r = -0.60, p<0.001). In fact, the amount of crude protein ingested to increase 1 kg of metabolic weight was positively correlated with the associated emissions (r=0.58, p<0.001). However, this was more related to the consumption by the animal than to the crude protein, which was relatively stable among diets. The difference between animals associated with high or low NH3 emissions per weight gain was therefore related to urine losses due to excess N intake. The energy balance shows that methane potential from slurry was mainly related to the excretion of indigested feed components, mainly the fibrous fraction (particularly the soluble fibre). It was clear that animals emitting high amounts of methane were those with higher dry matter and energy ingestion. The results of this study demonstrate relevant effects on N and energy balances at diets formulated according to commercial standards
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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