1,130 research outputs found
Determination of Evapotranspiration and Annual Biomass Productivity of a Cactus Pear [Opuntia ficus-indica L. (Mill.)] Orchard in a Semiarid Environment
A micrometeorological approach based on the surface energy balance was adopted to estimate evapotranspiration fluxes and crop
coefficient data from an irrigated cactus pear [Opuntia ficus-indica L. (Mill.)] orchard under Mediterranean climatic conditions. Highfrequency
temperature readings were taken above the canopy top to get sensible heat flux values (HSR) using the surface renewal technique.
These values were compared against eddy covariance sensible heat fluxes (HEC) for calibration. Latent heat flux (or evapotranspiration, ET)
was obtained by solving the daily energy balance equation. Measurements of soil hydraulic components were integrated with the analysis of
the surface energy fluxes and crop development in terms of phenology and aboveground biomass accumulation. Microlysimeters were used to
compute evaporation rates, allowing the separation of daily transpiration from ET data. Ecophysiological measurements were carried to
estimate dry weight accumulation and partitioning. Cactus pear evapotranspired a total of approximately 286 and 252 mm of water during
the two monitored growing seasons, respectively. Average daily values of crop (ETc) and reference (ET0) evapotranspiration were in the order
of 2.5 and 5.0 mm, respectively, with a corresponding value of the mean crop coefficient of approximately 0.40. The annual dry mass fixed per
single tree was 38.8 1.3 kg, with a total production of 12.9 t ha 121, which is comparable to many C3 and C4 plants and resulted in a water
use efficiency (WUE) of 4.6 and 4.4 gDMkgH2O 121 in 2009 and 2010, respectively. The stem area index (SAI) was 3.5
Determination of Evapotranspiration and Crop Coefficient of Cactus Pear (Opuntia ficus-indica Mill.) with an Energy Balance Technique
A micrometeorological approach based on surface renewal technique was adopted to estimate evapotranspiration fluxes and crop coefficient data from an irrigated cactus pear (Opuntia ficus-indica Mill.) orchard under Mediterranean
climatic conditions. High-frequency temperature readings were taken above the canopy top in order to get surface renewal sensible heat flux values (HSR). These values were compared against eddy covariance sensible heat fluxes (HEC) for
calibration. Latent heat flux (or evapotranspiration, ET) was obtained as the residual of the energy balance equation using HSR. In field measurements of biophysical crop features, physiological characteristic and soil hydraulic components
were integrated with the analysis of the surface energy fluxes. Microlysimeters were used to compute evaporation rates, allowing the separation of transpiration from ET data. During the irrigation season, evapotranspiration from the cactus pear orchard was 330 mm of water producing 16,210 kg of dry matter ha-1 for a biomass water
productivity: WPb = kg biomass m-2 per kg H2O m-2 = 6.6
710-3. The water use efficiency (WUE) was 204 kg H2O kg-1 dry matter. The low value of WPb, relative to other CAM plants, suggests an opportunity to improve the use of irrigation water
A Flexible Software Framework for Magnetic Measurements at CERN: a Prototype for the new Generation of Rotating Coils
A new software platform named FFMM (Flexible Framework for Magnetic Measurements) is under development at CERN (European Organization for Nuclear Research) in cooperation with the University of Sannio. The FFMM is aimed at facing the new test requirements arising after the production series of the Large Hadron Collider magnets. In particular, the basic concepts of the FFMM, its architecture, and the experimental implementation of a demonstrator are illustrated in order to show how the quality requirements of software flexibility and scalability are met
Characterization and development of different methods to extend shelf life of fresh cut fruit. Case study: novel controlled release system by layer-by-layer assembly
The research project aimed at the investigation of different methods for the storage of fresh-cut fruit. This case study relates to the proposal of an innovative controlled release system to improve the shelf life of ready-to-eat fruit. The methods applied during three research years included the application of active molecules from natural substances, some widely used in commerce and other tested for the first time; first analyzed in vitro and then applied in vivo. The under consideration methods concerned dipping, coating and the layer-by-layer assembly. The analysis carried out on the fruit have monitored pomological traits performances (soluble solids content, titratable acidity, pH, color, flesh firmness), the chemical profile (polyphenoloxidase, carotenoids) and microbial growth
Human-Scale Virtual Environment for Product Design: Effect of Sensory Substitution
This paper presents a human-scale virtual environment (VE) with haptic feedback along with two
experiments performed in the context of product design. The user interacts with a virtual mock-up using a large-scale bimanual string-based haptic interface called SPIDAR (Space Interface Device for Artificial Reality). An original self-calibration methodis proposed. A vibro-tactile glove was developed and integrated to the SPIDAR to provide tactile cues to the operator. The purpose of the first experiment was: (1) to examine the effect of tactile feedback in a task involving reach-and-touch of different parts of a digital mock-up, and (2) to investigate the use of sensory substitution in such tasks. The second experiment aimed to investigate the effect of visual and auditory feedback in a car-light maintenance task. Results of the first experiment indicate that the users could easily and quickly access and finely touch the different parts of the digital mock-up when sensory feedback (either visual, auditory, or tactile) was present. Results of the of the second experiment show that visual and auditory feedbacks improve average placement accuracy by about 54 % and 60% respectively compared to the open loop case.
Quality changes during postharvest life in white fleshed peach (Prunus Persica L. Batsch) fruits: Preliminary observations
Sicilian white flesh peach fruits ecotypes are characterized by a persistent aroma and excellent flavor that is highly appreciated by consumers. Nevertheless, they reach only regional markets, because of fruit sensitivity to decay and the poor information about their postharvest physiology and shelf-life. In this trial, we studied quality changes during postharvest life of non-melting white-flesh peach ecotypes \u2018Tudia\u2019, \u2018Bella di Bivona\u2019 and the cultivar \u2018Daniela\u2019. Fruits were collected at commercial ripening: a first group was submitted to analytical evaluations and another one was stored (2\ub0C, 90% RH) for 32 days. During this storage period, fruits were submitted to four shelf-life periods at ambient temperature (22\ub0C) for 6 days and analyzed every 3th and 6th day. In the period of shelf-life, during storage of fruit at 2\ub0C, we ascertained that Bella di Bivona and Daniela have a shelf-life of 12-14 days while \u2018Tudia\u2019 could reach up to 25-32 days. Flesh firmness and chilling injuries trends, during shelf-life, allowed to discover \u2018Tudia\u2019 as the variety which presents the best performance after storage at low temperatures for long periods
Fault self-defection of automatic testing systems by means of aspect-oriented programming
An Aspect Oriented approach to implement fault detection in automatic measurement systems is proposed. Faults are handled by means of "aspects", a specific software unit to better modularize issues transversal to many modules ("crosscutting concerns"). In this way, maintainability and reusability of a measurement software are improved: indeed, once a modification of the fault detection policy occurs, only the related aspects have to be modified. As an experimental case study, this technique has been applied to the fault self-detection of a flexible framework for magnetic measurements, developed at the European Organization for Nuclear Research (CERN)
Automated hippocampal segmentation in 3D MRI using random undersampling with boosting algorithm
Reconstruction of discontinuous parameters in a second order impedance boundary operator
International audienceWe consider the inverse problem of retrieving the coefficients of a second order boundary operator from Cauchy data associated with the Laplace operator at a measurement curve. We study the identifiability and reconstruction in the case of piecewise continuous parameters. We prove in particular the differentiability of the Khon-Vogelius functional with respect to the discontinuity points and employ the result in a gradient type minimizing algorithm. We provide validating numerical results discussing in particular the case of unknown number of discontinuity points
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