845 research outputs found

    Quantum Randomness Certified by the Uncertainty Principle

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    We present an efficient method to extract the amount of true randomness that can be obtained by a Quantum Random Number Generator (QRNG). By repeating the measurements of a quantum system and by swapping between two mutually unbiased bases, a lower bound of the achievable true randomness can be evaluated. The bound is obtained thanks to the uncertainty principle of complementary measurements applied to min- and max- entropies. We tested our method with two different QRNGs, using a train of qubits or ququart, demonstrating the scalability toward practical applications.Comment: 10 page

    Pneumatic press equipped with the Vortex system for white grapes processing: First results

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    The interaction between mechanical, computer and electronic technologies offers nowadays highly innovative solutions to be applied to the oenological machinery industry. Grapes pressing for the extraction of must from the grapes has a fundamental role for obtaining wines with high quality. The pneumatic presses commonly used work with a discontinuous cycle, taking on average about 3 hours for the extraction of the juice from the grapes. During this period, the presence of oxygen in contact with grapes can modify the qualitative characteristics of the future wine. The aim of the research was to study the \u201cVortex System\u201d applied to a pneumatic press and to evaluate the quality of wines obtained in reduction. The study was carried out in a modern winery in the province of Palermo (Italy) using cv. Catarratto lucido grapes. The machine used in the tests was a pneumatic press with a capacity of 1,900 / 2,500 kg by Puleo Srl company (Italy), equipped with the patent "Vortex System". It consists in the recovery of the inert gas by means of a passage and recirculation apparatus during grapes pressing allowing the must extraction in inert and controlled atmosphere, the non-oxidation of the product and a re-use of the gaseous component. Two operating modes were applied: AP (Air Pressing) mode, the traditional pressing mode in presence of oxygen, and NP (Nitrogen Pressing) mode with the Vortex System, performed under inert gas with nitrogen recovery. The following analytical determinations were performed on wines in triplicates: alcohol [%/vol], density [g/l], sugar [g/l], pH, total acidity [g/l], volatile acidity [g/l], malic acid [g/l], citric acid [g/l], tartaric acid [g/l], potassium [g/l], glycerin [g/l], ashes [g/l], absorbance at 420, 520 and 620 nm, polyphenols [mg/l], catechins [mg/l], free sulfur dioxide [mg/l], total sulfur dioxide [mg/l]. The use of the pneumatic press equipped with the Vortex System allowed to obtain excellent values of volatile acidity, absorbance at 420 nm, catechins in white wines and a rich aromatic component both in primary and secondary aromas

    Bi-photon propagation control with optimized wavefront by means of Adaptive Optics

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    We present an efficient method to control the spatial modes of entangled photons produced through SPDC process. Bi-photon beam propagation is controlled by a deformable mirror, that shapes a 404nm CW diode laser pump interacting with a nonlinear BBO type-I crystal. Thanks to adaptive optical system, the propagation of 808nm SPDC light produced is optimized over a distance of 2m. The whole system optimization is carried out by a feedback between deformable mirror action and entangled photon coincidence counts. We also demonstrated the improvement of the two-photon coupling into single mode fibers

    Evaluation of the vibrations transmitted to the hand-arm system in the use of portable harvesters for olives

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    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

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    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

    Complete and Deterministic discrimination of polarization Bell state assisted by momentum entanglement

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    A complete and deterministic Bell state measurement was realized by a simple linear optics experimental scheme which adopts 2-photon polarization-momentum hyperentanglement. The scheme, which is based on the discrimination among the single photon Bell states of the hyperentangled state, requires the adoption of standard single photon detectors. The four polarization Bell states have been measured with average fidelity F=0.889±0.010F=0.889\pm0.010 by using the linear momentum degree of freedom as the ancilla. The feasibility of the scheme has been characterized as a function of the purity of momentum entanglement.Comment: 4 pages, v2, comments adde

    Acceleration assessment during mechanical harvest of grapes using a non commercial instrumented sphere

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    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

    Use of a portable VIS NIR device to predict table olives quality

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    There is a growing interest today in high-quality and sustainable production especially in the agro-food sector where the use of automated, precise and non-destructive monitoring analytical systems is spreading more and more. In table olives consumption colour and texture are very important quality attributes deriving from ripening, size of the cell wall, middle lamella and fibrous tissues that can be compromised by bruising during harvest operations or postharvest handling. Mechanical damage also accelerates physiological processes, which lead to senescence, spoilage and loss of nutritional value. Nocellara del Belice cultivar is one of the most important table olive varieties in Italy both for the production and the marketed quantities, with an average annual production of 25,000 t. The aim of this study was to evaluate the feasibility of applying vis NIR spectroscopy as a non-destructive technique on Nocellara del Belice table olives to predict colour and firmness during harvest and post-harvest operations. The spectral acquisitions were performed using a portable vis NIR device (600 - 1000 nm). A regression model was considered to evaluate the prediction capacity of vis NIR starting from the observed values of a validation data set. The system gave excellent performance in predicting table olives colour (R2 = 0.96 for “hue”), while the results showed a very low vis NIR ability to predict Nocellara del Belice table olives firmness (R2 = 0.18) which make this device unsuitable for the purpose. The possibility of applying vis NIR spectroscopy in field before harvest or for selection in postharvest operations is very encouraging for colour prediction and seems to be not adequate for firmness or damage evaluation

    Influence of O2 on extra virgin olive oil fatty acids composition during malaxation

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    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

    Quality evaluation of grapes for mechanical harvest using vis NIR spectroscopy

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    Mechanical harvest of grapes is one of the operations that mostly influence the quality of the future wine. The shaking frequency of the harvesting machine is usually adjusted on the basis of the grape berry characteristics in order to limit grape juice production that is a potential cause of uncontrolled fermentations. These evaluations usually require time, personnel and laboratory analyses. The introduction of a vis NIR system to rapidly and reliably evaluate the berry properties in field before mechanical harvest could be a good alternative. The aim of this study was to evaluate the feasibility of applying vis NIR spectroscopy as a non-destructive technique on grapes cv. Syrah and Chardonnay to predict pedicel detachment force, pH and total soluble solids before mechanical harvest. The spectral acquisitions were performed using a portable vis NIR device (600-1000 nm). An Ordinary Least Square evaluation was applied to assess vis NIR prediction ability on grapes. The system gave excellent performance in predicting pH for both varieties (R 2 = 0.99), also confirmed by the indicators SECV/M and Bias/M respectively equal to 0.024 and 0.014 for cv. Syrah and 0.002 and -0.009 for Chardonnay. The vis NIR device showed satisfactory prediction ability even regarding total soluble solids (R 2 = 0.997 for Syrah and 0.9935 for Chardonnay) with SECV/M = 0.090, Bias/M = 0.071 for cv. Syrah and SECV/M = 0.00, Bias/M = -0.002 for Chardonnay. However, the results showed the low vis NIR ability to predict detachment force for Chardonnay grapes (R 2 = 0.85, SECV/M = 1.008; Bias/M = -0.834), and an acceptable one for Syrah grapes (R 2 = 0.87; SECV/M = 0.362; Bias/M = -0.109). Since detachment force has an enormous importance in grapes mechanical harvest, the possibility of applying vis NIR spectroscopy in field before harvest is very encouraging for cv. Syrah (red grapes) and needs to be improved for cv. Chardonnay (white grapes)
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