1,931 research outputs found
Global existence for two regularized MHD models in three space-dimension
The global existence of solutions for the 3D incompressible Euler equations is a major open problem. For the 3D inviscid MHD system, the global existence is an open problem as well. Our main concern in this paper is to understand which kind of regularization, of the form of alpha-regularization or partial viscous regularization, is capable to provide the global in time solvability for the 3D inviscid MHD system of equations. We consider two different regularized magnetohydrodynamic models for an incompressible fluid. In both cases, we provide a global existence result for the solution of the system
Activity of eribulin mesylate in brain metastasis from breast cancer. a stone in a pond?
Background: Brain metastases develop in approximately 10-25% of patients with metastatic breast cancer (MBC) and are associated with a very poor prognosis. Case Report: We report the case of a 40-year-old woman with MBC and associated lung, bone, liver, and brain metastases, who experienced a time to progression of several months with eribulin after whole-brain radiotherapy (WBRT), 2 lines of chemotherapy, and 1 line of hormonal therapy, maintaining a good toxicity profile. Discussion: Eribulin, in association with local treatment such as WBRT, can be well tolerated and effective in achieving a long progression-free survival and a good control of brain metastases in patients with MBC who have received multiple lines of treatment. The vascular remodeling properties of eribulin, combined with brain radiotherapy, might facilitate the passage of eribulin across the blood brain barrier, improving brain response. Conclusion: Our anecdotal experience suggests that eribulin may have a potentially beneficial effect on brain metastases while maintaining a good systemic control of the disease in patients with MBC
Evaluation of the vibrations transmitted to the hand-arm system in the use of portable harvesters for olives
The use of portable harvesters in olives harvesting is presently widely diffused in Sicily, south Italy, both to reduce the costs of production and to assure the olive oil quality. Nevertheless, it's well known that the use of such tools may involve risk of exposure to vibration transmitted to the hand-arm system which is a potential cause of muscular/skeletal pains, and specific pathologies such as Hand-Arm Vibration Syndrome (HAVS), Vibration-Induced White Finger (VWF) and Carpal Tunnel Syndrome (CTS). The aim of this study was to assess the level of exposure to vibration transmitted to the hand-arm system of the operators during the use of portable harvesters for olives. Two different commonly used types of tools were evaluated performing both laboratory and field tests. One was a hook type harvester provided with an internal combustion engine; the other an electric portable harvester consisting of a bar ending with a comb, equipped with an electric motor. The daily action value established by the European Directive 2002/44/EC was always considerably exceeded by the two harvesters for both hands both in the laboratory and in the field tests; however, the electric comb showed A(8) values about halved with respect to the hook type, equal to 20.79 and 18.69 m s-2 respectively for right and left hand in the field tests against 42.07 and 30.03 m s-2 obtained with the hook type harvester
Noise risk assessment in a modern olive oil mill
High levels of noise usually occur in olive oil mills because of the machines used to extract olive oil with a continuous plant. In Italy Law Decree 81/2008 defined the requirements for assessing and managing noise risk, identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This study aims at evaluating the equivalent and peak noise levels inside a modern oil mill plant area in Sicily, south Italy. Twenty measurement points were identified inside the oil mill plant area where the machines for olive oil extraction were located (about 200 m2). The instrument used for the measurements was a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. The measured sound levels exceeded the limits allowed by the regulations in all the measurement points inside the working area; values exceeding the threshold limit of 80 dB(A) were recorded coming up to a maximum value of 93.3 dB(A) close to the hammer crusher. The operators involved are consequently obliged to wear the appropriate Personal Protective Equipment
Influence of O2 on extra virgin olive oil fatty acids composition during malaxation
Many variables are related to extra virgin olive oil (EVOO) quality and, therefore, to its polyphenols content and fatty acids composition including the steps that lead to EVOO extraction, considering that it is mainly contained in the vacuoles of the fruit mesocarp. The main steps of EVOO production are: harvest, crushing, malaxation, centrifugation, storage and filtration. Considering the olive oil extraction procedures, many studies have been conducted in recent years on oil mill plant and processes for improving EVOO quality. Malaxer is the most studied machine among all; it is responsible for malaxation, which represents a very important and critical step in the EVOO extraction process. Many studies focus on the control of oxygen in the malaxer headspace, with the aim of determining its influence on EVOO quality evaluating volatile and phenolic components. Considering these factors, the main objective of the present study was to evaluate the influence of the malaxer headspace oxygen concentration on EVOO fatty acids composition from cv. Nocellara del Belice olives. The results show that oxygen content in the malaxer headspace, in different time-points and concentrations during the process, influences EVOO fatty acids composition
Influence of the pressing system on pomegranate juice physical-chemical properties
Pomegranate juice has many health properties as the fruits contain anticarcinogenic, antimicrobial and antiviral compounds. Its consumption has greatly increased throughout the world in recent years due to the potential of its different components, polyphenols and anthocyanins among all. Many studies have been performed on the pomegranate juice yield demonstrating its influence on the organoleptic and physicochemical properties of the juice. Commercial pomegranate juice production involves pressing fruits procedures. As a consequence, there is a need to investigate the pressing machine types and optimization in order to achieve juice yield and enhance its health properties. The aim of this study was to assess the influence of the pressing systems on pomegranate juice yield and health properties after the extraction. Pomegranate fruits of the Wonderful One variety were manually harvested in November 2014 and mechanically processed to extract juice. Two different pressing systems were used. The first one was an hydraulic pressing machine where the fruits were put after being sliced in half; the second extraction method consisted in using a destemming machine for the entire fruit followed by a pneumatic press, typically applied in grape processing. The juices obtained with the two systems were analyzed and compared in order to identify the extraction performances and quantitatively identify the health care of the juice properties
Acceleration assessment during mechanical harvest of grapes using a non commercial instrumented sphere
The use of the harvesting machine for grape wine has the limit of the production of must coming out from the detachment of the berries that could reflect negatively on the quality of the final product. It depends on many factors including grapes variety, ripeness and frequency of the harvesting machine shakers. The shaking frequency generally adopted is the one that achieves the maximum harvest efficiency, that means high work capacity and low grape juice production. In this paper, the authors present a new system to measure the accelerations received by grapevine during mechanical harvest with the aim of evaluating the influence of the shaking frequency on the quality of the must obtained. The device is an instrumented sphere designed and implemented by the Agricultural Mechanics Section of the Department of Agricultural and Forest Sciences, University of Palermo, Italy. It contains a triaxial Micro Electro-Mechanical Systems (MEMS) sensor capable of acquiring acceleration from a few mg to 400 g (where g is the gravitational acceleration). The field tests were carried out in September 2015 on Viognier and Grillo grapes. They allowed to measure the accelerations on the plants during mechanical grape harvest with three different shaking frequencies: 7.6, 7.9 and 8 Hz, and then to evaluate their influence on the main quality characteristics of the musts obtained. The results showed that the number of vibrations on the plants linearly increases with the increasing frequency. With reference to the quality of the musts obtained, polyphenols and catechins increased as the shaking frequency increased both for Viognier and Grillo varieties
Comparison of different computer vision methods for vineyard canopy detection using UAV multispectral images
In viticulture, the rapid and accurate acquisition of canopy spectral information through ultra-high spatial resolution imagery is increasingly demanded for decision support. The prevalent practice involves creating vigor maps using spectral data obtained from pure vine canopy pixels. Object-Based Image Analysis (OBIA) among conventional methods exhibits a reasonable efficiency in canopy classification due to its feature extraction capabilities. In recent years, deep learning (DL) techniques have demonstrated significant potential in orchard monitoring, leveraging their ability to automatically learn image features. This study assessed the performance of different methodologies, including Mask R-CNN, U-Net, OBIA and unsupervised methods, in identifying pure canopy pixels. The effectiveness of shadow and background detection methods and the impact of misclassified pixels on NDVI were compared. Results were compared with agronomic surveys conducted during the 2021 and 2022 growing seasons, focusing on two distinct phenological stages (BBCH65-BBCH85). Mask R-CNN and U-Net exhibited superior performance in terms of Overall Accuracy (OA), F1-score, and Intersection Over Union (IoU). Among OBIA methods, the Gaussian Mixture Model (GMM) proved to be the most effective classifier for canopy segmentation, and Support Vector Machine (SVM) also demonstrated reasonable stability. Conversely, Random Forest (RF) and K-Means yielded lower accuracy and higher error rates. As a result of the limited accuracy, it is noted for vineyard rows with low vigor canopies that NDVI was overestimated, while for high vigor canopies NDVI was underestimated. Significantly improved determination coefficients were observed for the comparison between Total Leaf Area (TLA) and NDVI data derived from Mask R-CNN and U-Net. Positive correlations were also found with NDVI data from GMM and SVM algorithms. Regarding leaf chlorophyll (Chl) and NDVI correlations, Mask R-CNN and U-Net methods showed superior performance. Additionally, the relationship between TLA and projected canopy area (PCA) was significantly better represented by U-Net and Mask R-CNN, while PCA was not recommended for estimating chlorophyll content. This investigation establishes that improved vine canopy delimitation contributes to improved vineyard vigour monitoring, providing winegrowers with more accurate and reliable agronomic information for management decisions
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