1,101 research outputs found

    Utilizing Mixture Regression Models for Clustering Time-Series Energy Consumption of a Plastic Injection Molding Process

    Get PDF
    Considering the issue of energy consumption reduction in industrial plants, we investigated a clustering method for mining the time-series data related to energy consumption. The industrial case study considered in our work is one of the most energy-intensive processes in the plastics industry: the plastic injection molding process. Concerning the industrial setting, the energy consumption of the injection molding machine was monitored across multiple injection molding cycles. The collected data were then analyzed to establish patterns and trends in the energy consumption of the injection molding process. To this end, we considered mixtures of regression models given their flexibility in modeling heterogeneous time series and clustering time series in an unsupervised machine learning framework. Given the assumption of autocorrelated data and exogenous variables in the mixture model, we implemented an algorithm for model fitting that combined autocorrelated observations with spline and polynomial regressions. Our results demonstrate an accurate grouping of energy-consumption profiles, where each cluster is related to a specific production schedule. The clustering method also provides a unique profile of energy consumption for each cluster, depending on the production schedule and regression approach (i.e., spline and polynomial). According to these profiles, information related to the shape of energy consumption was identified, providing insights into reducing the electrical demand of the plant

    Cloaking using the anisotropic multilayer sphere

    Get PDF
    We studied a Spherically Radially Anisotropic (SRA) multilayer sphere with an arbitrary number of layers. Within each layer permittivity components are different from each other in radial and tangential directions. Under the quasi-static approximation, we developed a more generalized mathematical model that can be used to calculate polarizability of the SRA multilayer sphere with any arbitrary number of layers. Moreover, the functionality of the SRA multilayer sphere as a cloak has been investigated. It has been shown that by choosing a suitable contrast between components of the permittivity, the SRA multilayer sphere can achieve threshold required for invisibility cloaking

    Task demands dissociate the effects of muscarinic M-1 receptor blockade and protein kinase C inhibition on attentional performance in rats

    Get PDF
    The cholinergic system is known to be necessary for normal attentional processing. However, the receptors and mechanisms mediating the effects of acetylcholine on attention remain unclear. Previous work in our laboratory suggested that cholinergic muscarinic receptors are critical for maintaining performance in an attention-demanding task in rats. We examined the role of the muscarinic M-1 receptor and protein kinase C (PKC), which is activated by the M-1 receptor, in attention task performance. Rats were trained in an attention-demanding task requiring discrimination of brief (500, 100, 25 ms) visual signals from trials with no signal presentation. The effects of muscarinic M-1 receptor blockade were assessed by administering dicyclomine (0-5.0 mg/kg). The effects of PKC inhibition were assessed by administering chelerythrine chloride (0-2.0 mg/kg). Dicyclomine decreased the accuracy of detecting longer signals in this attention task, including when attentional demands were increased by flashing a houselight throughout the session. Chelerythrine chloride decreased the accuracy of signal detection in the standard version of the task but not when the houselight was flashed throughout the session. The present findings indicate that muscarinic M-1 receptors are critical for maintaining performance when attentional demands are increased, and that PKC activity may contribute to some aspects of attentional performance

    Effect of the Ambient Temperature on the Start-Up of a Multi-Evaporator Loop Thermosyphon

    Get PDF
    Two-phase heat transfer devices are becoming fairly ubiquitous; the capability to transport heat at high rates over appreciable distances, without any external pumping device, the low cost, durability and relatively simpler modeling/design process, make this technology very attractive for many thermal management applications. Indeed, such devices have been investigated in plenty of fields such as: nuclear plants, energy systems, solar heat recovery, air conditioning, electronic cooling in avionics and in railway traction. As a consequence, they can operate under different environmental conditions that can affect their behavior. Nevertheless, it is difficult to find in literature something related to the effect of the ambient temperature on the thermal performance of such devices. The actual temperature, varying the thermo-fluid properties of the fluid inside the device, the condensation and the evaporation phenomena, could be an important parameter that can affect the performance. In this work a Multi-Evaporator loop thermosyphon is tested at different ambient temperatures, ranging from -20 °C up to 30 °C. The start-up behavior, as well as the thermal performance, are analyzed by means of temperature and pressure measurements and fluid flow visualization

    Il Centro studi interateneo Notariorum itinera

    Get PDF
    Il Centro studi interateneo Notariorum Itinera con sede amministrativa presso l\u2019Universit\ue0 degli Studi di Genova e sedi consorziate le Universit\ue0 degli Studi di Bari, Bologna, Catanzaro, Milano Statale, Pavia, Roma Tor vergata, Salerno e Torino \ue8 stato formalmente costituito nel maggio 2017. L\u2019obiettivo \ue8 quello di studiare il notariato, i registri notarili italiani ed europei e, pi\uf9 in generale, tutte le fonti a essi collegate per addivenire a una conoscenza a tutto tondo 12 senza limiti cronologici e geografici 12 dell\u2019attivit\ue0 di questa figura professionale. Il contributo propone una breve analisi dello status questionis e illustra i primi risultati delle indagini in corso.Centro studi interateneo Notariorum Itinera \u2013 headquarter at the University of Genoa and subsidiaries at the Universities of Bari, Bologna, Catanzaro, Milan Statale, Pavia, Rome Tor vergata, Salerno and Turin \u2013 was formally established in May 2017. The aim of Centro studi is to study notary, Italian and european notarial registers and, more widely, all the related records in order to get a full knowledge \u2013 without chronological and geographical limits \u2013 of the activity of this professional category. The paper focuses on the status questionis and illustrates the first results of ongoing studies

    Candidate genes and quantitative trait loci for grain yield and seed size in durum wheat

    Get PDF
    Grain yield (YLD) is affected by thousand kernel weight (TKW) which reflects the combination of grain length (GL), grain width (GW) and grain area (AREA). Grain weight is also influenced by heading time (HT) and plant height (PH). To detect candidate genes and quantitative trait loci (QTL) of yield components, a durum wheat recombinant inbred line (RIL) population was evaluated in three field trials. The RIL was genotyped with a 90K single nucleotide polymorphism (SNP) array and a high-density genetic linkage map with 5134 markers was obtained. A total of 30 QTL were detected including 23 QTL grouped in clusters on 1B, 2A, 3A, 4B and 6B chromosomes. A QTL cluster on 2A chromosome included a major QTL for HT co-located with QTL for YLD, TKW, GL, GW and AREA, respectively. The photoperiod sensitivity (Ppd-A1) gene was found in the physical position of this cluster. Serine carboxypeptidase, Big grain 1 and β-fructofuranosidase candidate genes were mapped in clusters containing QTL for seed size. This study showed that yield components and phenological traits had higher inheritances than grain yield, allowing an accurate QTL cluster detection. This was a requisite to physically map QTL on durum genome and to identify candidate genes affecting grain yield

    Dynamics of high-energy multimode Raman solitons

    Get PDF
    The dynamics of high-energy Raman solitons in graded-index multimode fibers is both numerically and experimentally investigated. The propagation of high-power pulses produces nonlinear losses, that quench up to 80% of the fiber transmission. In such a regime, several solitons arising from the fission of ultra-short femtosecond pulses manifest unique features: pulse width, Raman self-frequency shift and soliton order remain nearly constant over a broad range of energies

    Calorimetry of photon gases in nonlinear multimode optical fibers

    Full text link
    Because of their massless nature, photons do not interact in linear optical media. However, light beam propagation in nonlinear media permits to break this paradigm, and makes it possible to observe photon-photon interactions. Based on this principle, a beam of light propagating in a nonlinear multimode optical system can be described as a gas of interacting particles. As a consequence, the spatio-temporal evolution of this photon gas is expressed in terms of macroscopic thermodynamic variables, e.g., temperature and chemical potential. Moreover, the gas evolution is subject to experiencing typical thermodynamic phenomena, such as thermalization. The meaning of thermodynamic variables associated with the photon gas must not be confused with their classical counterparts, e.g., the gas temperature cannot be measured by means of standard thermometers. Although the thermodynamic parameters of a multimode photon gas result from a rigorous mathematical derivation, their physical meaning is still unclear. In this work, we report on optical calorimetric measurements, which exploit nonlinear beam propagation in multimode optical fibers. Our results show that, indeed, heat only flows from a hot to a cold photon gas subsystem. This provides an unequivocal demonstration that nonlinear multimode wave propagation phenomena are governed by the second law of thermodynamics. In addition to be fundamental, our findings provide a new approach to light-by-light activated management of laser beams
    • …
    corecore