2,840 research outputs found

    New Constraints on General Slepton Flavor Mixing

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    We explore the phenomenological implications on charged lepton flavor violating (LFV) processes from slepton flavor mixing within the Minimal Supersymmetric Standard Model. We work under the model-independent hypothesis of general flavor mixing in the slepton sector, being parametrized by a complete set of dimensionless delta^AB_ij (A,B = L,R; i,j = 1, 2, 3) parameters. The present upper bounds on the most relevant LFV processes, together with the requirement of compatibility in the choice of the MSSM parameters with the recent LHC and (g-2) data, lead to updated constraints on all slepton flavor mixing parameters. A comparative discussion of the most effective LFV processes to constrain the various generation mixings is included.Comment: 42 pages, 19 figures. Minor changes, version to appear in PR

    Updated Constraints on General Squark Flavor Mixing

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    We explore the phenomenological implications on non-minimal flavor violating (NMFV) processes from squark flavor mixing within the Minimal Supersymmetric Standard Model. We work under the model-independent hypothesis of general flavor mixing in the squark sector, being parametrized by a complete set of dimensionless delta^AB_ij (A,B = L, R; i,j = u, c, t or d, s, b) parameters. The present upper bounds on the most relevant NMFV processes, together with the requirement of compatibility in the choice of the MSSM parameters with the recent LHC and g-2 data, lead to updated constraints on all squark flavor mixing parameters.Comment: 30 pages, 7 figures. arXiv admin note: text overlap with arXiv:1304.2783, arXiv:1109.623

    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

    Damping oriented design of thin-walled mechanical components by means of multi-layer coating technology

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    The damping behaviour of multi-layer composite mechanical components, shown by recent research and application papers, is analyzed. A local dissipation mechanism, acting at the interface between any two different layers of the composite component, is taken into account, and a beam model, to be used for validating the known experimental results, is proposed. Multi-layer prismatic beams, consisting of a metal substrate and of some thin coated layers exhibiting variable stiffness and adherence properties, are considered in order to make it possible to study and validate this assumption. A dynamical model, based on a simple beam geometry but taking into account the previously introduced local dissipation mechanism and distributed visco-elastic constraints, is proposed. Some different application examples of specific multi-layer beams are considered, and some numerical examples concerning the beam free and forced response are described. The influence of the multilayer system parameters on the damping behaviour of the free and forced response of the composite beam is investigated by means of the definition of some damping estimators. Some effective multi-coating configurations, giving a relevant increase of the damping estimators of the coated structure with respect to the same uncoated structure, are obtained from the model simulation, and the results are critically discussed

    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

    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
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