Search results for " harvesting"
showing 10 items of 180 documents
Evaluation of hand-arm vibrations during the use of portable olives harvesters
2013
The use of portable shakers in olives harvesting is becoming increasingly, especially in Sicily, both to reduce the costs of production and to assure the oil quality. Nevertheless, it’s well known that the use of such tools may involve risk of exposure to hand-transmitted vibration. Such exposure to vibrations is a potential cause of muscular/skeletal pains in hand–arm system, and specific pathologies such as Vibration-Induced White Finger (VWF) and Carpal Tunnel Syndrome (CTS), Hand–Arm Vibration Syndrome (HAVS). The aim of this study was to assess the level of exposure to hand-arm vibration of the operators during the use of portable shakers for olives harvesting. Two different commonly u…
Optical Plasmonic Nano-Antennas Array for Energy Harvesting Applications
2019
Optical nanoantennas have been of great interest recently due to their ability to support a highly efficient, localized surface plasmon resonance and produce significantly enhanced and highly confined electromagnetic fields. The Yagi nanoantenna, an optical analog of the well-established radiofrequency Yagi antenna, stands out by its efficient unidirectional light emission and enhancement. In this paper, an investigation on a novel optical plasmonic nanoantennas array for energy harvesting application is proposed. The study of a novel Yagi nanorectennas array, by optimizing its geometrical parameters, is reported. All the simulations are carried out by using the CST Studio Suite 2018 softwa…
Impeller optimization in crossflow hydraulic turbines
2021
Crossflow turbines represent a valuable choice for energy recovery in aqueducts, due to their constructive simplicity and good efficiency under variable head jump conditions. Several experimental and numerical studies concerning the optimal design of crossflow hydraulic turbines have already been proposed, but all of them assume that structural safety is fully compatible with the sought after geometry. We show first, with reference to a specific study case, that the geometry of the most efficient impeller would lead shortly, using blades with a traditional circular profile made with standard material, to their mechanical failure. A methodology for fully coupled fluid dynamic and mechanical …
Virtual Resource Allocation for Wireless Virtualized Heterogeneous Network with Hybrid Energy Supply
2022
In this work, two novel virtual user association and resource allocation algorithms are introduced for a wireless virtualized heterogeneous network with hybrid energy supply. In the considered system, macro base stations (MBSs) are supplied by the grid power and small base stations (SBSs) have the energy harvesting capability in addition to the grid power supplement. Multiple infrastructure providers (InPs) own the physical resources, i.e., BSs and radio resources. The Mobile Virtual Network Operators (MVNOs) are able to recent these resources from the InPs and operate the virtualized resources for providing services to different users. In particular, aiming to maximize the overall utility …
First tests of mechanical harvest of Origanum vulgare L.
2003
In Italy Origanum vulgare L. is cultivated only in few areas and its production does not even satisfy the national market demand. Until now the interest on this crop has been very low because of the high cost of manual harvest and bunch binding. The aim of this work is to evaluate the use of a reaper-binder (made for harvesting cereal crops) for harvesting and bunch binding Origanum vulgare L. The tests were carried out in Sicily, in the summer of 2001. The mechanical harvest was carried out using the reaper-binder unmodified, but the results were not satisfactory. The machine was then modified reducing its forward speed and cutting height, in order to improve its working productivity and h…
Carbon Nanodots: A Review—From the Current Understanding of the Fundamental Photophysics to the Full Control of the Optical Response
2018
Carbon dots (CDs) are an emerging family of nanosystems displaying a range of fascinating properties. Broadly speaking, they can be described as small, surface-functionalized carbonaceous nanoparticles characterized by an intense and tunable fluorescence, a marked sensitivity to the environment and a range of interesting photochemical properties. CDs are currently the subject of very intense research, motivated by their possible applications in many fields, including bioimaging, solar energy harvesting, nanosensing, light-emitting devices and photocatalyis. This review covers the latest advancements in the field of CDs, with a focus on the fundamental understanding of their key photophysica…
Comments on the through space singlet energy transfers and energy migration (exciton) in the light harvesting systems
2008
Recent findings on the photophysical investigations of several cofacial bisporphyrin dyads for through space singlet and triplet energy transfers raised several serious questions about the mechanism of the energy transfers and energy migration in the light harvesting devices, notably LH II, in the heavily studied purple photosynthetic bacteria. The key issue is that for simple cofacial or slipped dyads with controlled geometry using rigid spacers or spacers with limited flexibilities, the fastest possible rates for singlet energy transfer for three examples are in the 10 x 10(9)s(-1) (i.e. just in the 100 ps time scale) for donor-acceptor distances approaching 3.5-3.6 A. The reported time s…
Coherent Light Harvesting through Strong Coupling to Confined Light
2018
When photoactive molecules interact strongly with confined light modes, new hybrid light–matter states may form: the polaritons. These polaritons are coherent superpositions of excitations of the molecules and of the cavity photon. Recently, polaritons were shown to mediate energy transfer between chromophores at distances beyond the Forster limit. Here we explore the potential of strong coupling for light-harvesting applications by means of atomistic molecular dynamics simulations of mixtures of photoreactive and non-photo-reactive molecules strongly coupled to a single confined light mode. These molecules are spatially separated and present at different concentrations. Our simulations sug…
Using Macroelement Content to Characterize Surficial Water Quality of Artificial Reservoirs
2021
Abstract The quality of surface waters in the territory of Poland, despite the implemented remedial measures, is mostly classified as bad. This article presents the results of research on the composition of water macroelements in 24 artificial reservoirs located in Opole province (southern Poland), searching for the reasons behind their pollution. Concentrations of the anions F−, Cl−, Br−, NO2−, NO3−, PO43− and SO42− and cations Na+, NH4+, K+, Mg2+ and Ca2+ were taken into account. An analysis of seasonal changes was carried out and, on the example of a dam reservoir (Turawa Big Reservoir), a multi-point analysis of the distribution of ion concentrations in water at the reservoir surface w…
Rainwater Reuse in Urban Areas: A Mathematical Model and a Long-Term Modelling Approach
2018
Natural water resources are becoming increasingly limited due to global-scale climate change and water availability issues have become so severe that they must be addressed. Given these issues, reuse of wastewater and rainwater provides a promising way to cope with water shortages. This paper describes an investigation into the efficiency of rainwater usage systems. A conceptual model was built to assess the behaviour of rainwater tanks and their effectiveness in coping with water shortages. The study is based on a long-term simulation (12 years) of different rainwater reuse tank schemes. The associated reductions in residential freshwater demand (water reuse efficiency) and wet-weather run…