Search results for "PET"
showing 10 items of 12749 documents
Automatic Operation and Control of a Novel Coalescing Centrifugal Pump for Improved Oil/Water Separation
2019
Summary In this paper we present the development and implementation of automatic operation and control for a pump/hydrocyclone produced-water-treatment system to maximize oil/water-separation efficiency. A so-called perturb-and-observe (P&O) algorithm is adapted for a novel centrifugal pump to continuously optimize the point of operation. The novel pump coalesces and increases the size of oil droplets in the produced water, resulting in a unique relationship between the coalescing effect and the point of operation, and allowing for the successful implementation of the P&O algorithm. The algorithm was implemented in two different setups, one measuring the droplet-size distribution be…
An expansion–coalescence model to track gas bubble populations in magmas
2016
Abstract We propose a kinetic model that statistically describes the growth by decompression, exsolution and coalescence of a polydisperse population of gas bubbles in a silicate melt. The model is homogeneous in space and its main variable is a distribution function representing the probability to find a bubble of volume v and mass m at time t. The volume and mass growth rates are described by a simplification of the classical monodisperse bubble growth model. This simplification, which shortens computational time, removes the coupling between mass evolution and an advection–diffusion equation describing the behavior of the volatile concentration in the melt. We formulate three coalescence…
Dynamics of mild strombolian activity on Mt. Etna
2015
Abstract Here we report the first measurements of gas masses released during a rare period of strombolian activity at the Bocca Nuova crater, Mt. Etna, Sicily. UV camera data acquired for 195 events over an ≈ 27 minute period (27th July 2012) indicate erupted SO2 masses ranging from ≈ 0.1 to ≈ 14 kg per event, with corresponding total gas masses of ≈ 0.1 to 74 kg. Thus, the activity was characterised by more frequent and smaller events than typically associated with strombolian activity on volcanoes such as Stromboli. Events releasing larger measured gas masses were followed by relatively long repose periods before the following burst, a feature not previously reported on from gas measureme…
2017
Strombolian volcanism is a ubiquitous form of activity, driven by the ascent and bursting of bubbles of slug morphology. Whilst considerable attention has been devoted to understanding the behaviour of individual slugs in this regime, relatively little is known about how inter-slug interactions modify flow conditions. Recently, we reported on high temporal frequency strombolian activity on Etna, in which the larger erupted slug masses were followed by longer intervals before the following explosion than the smaller bursts (Pering et al., 2015). We hypothesised that this behaviour arose from the coalescence of ascending slugs causing a prolonged lag before arrival of the next distinct bubble…
Le costituzioni superflue del Codice di Giustiniano, secondo Taleleo
2019
Giustiniano, nelle costituzioni introduttive dei Digesta, del Codice e delle Istituzioni, dichiara di volere perseguire una finalità di certezza del dritto (ius certum), anche per mezzo della rimozione di leges considerate superflue o ripetitive.Tuttavia, un'indagine, mai compiuta in precedenza, sul commento di Taleleo al Codice, permette di rintracciare nel commento di questo antecessore sette giudizi di superfluità di altrettante costituzioni imperiali. Il lavoro si propone di riflettere sul modo in cui i compilatori perseguirono la finalità di creare un ius certum e sui suggerimenti pratici forniti agli studenti dei corsi degli antecessori Justinian, in the introductory constitutions of …
Dietary and Temporal Niche Differentiation in Tropical Ants-Can They Explain Local Ant Coexistence?
2014
How species with similar ecological requirements avoid competitive exclusion remains contentious, especially in the species-rich tropics. Niche differentiation has been proposed as a major mechanism for species coexistence. However, different niche dimensions must be studied simultaneously to assess their combined effects on diversity and composition of a community. In most terrestrial ecosystems, ants are among the most abundant and ubiquitous animals. Since they display direct, aggressive competition and often competitively displace subordinate species from resources, niche differentiation may be especially relevant among ants. We studied temporal and trophic niche differentiation in a gr…
Plant facilitation and phylogenetics
2013
The relationship between facilitation and evolutionary ecology is poorly understood. We review five issues elucidating how the phylogenetic relatedness of species provides insight into the role of facilitation in community assembly: (a) Are the facilitative interactions more common between species that differ in a regeneration niche? (b) Are facilitative interactions more common between distantly related species? (c) Do communities governed by facilitation (rather than competition) have higher phylogenetic diversity? (d) As facilitated juvenile plants mature, do they compete with their nurses more often if they are closely related to them? (e) How does the phylogenetic signature in a commun…
Pheromone-induced olfactory memory in newborn rabbits: Involvement of consolidation and reconsolidation processes.
2009
Mammary pheromone (MP)-induced odor memory is a new model of appetitive memory functioning early in a mammal, the newborn rabbit. Some properties of this associative memory are analyzed by the use of anisomycin as an amnesic agent. Long-term memory (LTM) was impaired by anisomycin delivered immediately, but not 4 h after either acquisition or reactivation. Thus, the results suggest that this form of neonatal memory requires both consolidation and reconsolidation. By extending these notions to appetitive memory, the results reveal that consolidation and reconsolidation processes are characteristics of associative memories of positive events not only in the adult, but also in the newborn.
Multimodality: Art as a Meaning-Making Process
2021
AbstractThe authors of the book see multimodality as intrinsic to human communication and texts, and as consisting of a multiplicity of signs. This chapter discusses how this applies in educational settings, to examine how different modes of communication are intertwined and utilized in learning, including children’s creative learning practices. In this, the authors use the semiotic concepts that operate in all communicative contexts: Field, tenor, and mode. Through them, the authors view the CLLP as a space that enables social activities, exploration of cultural, social, and societal contents and topics, and the development of social relationships. All this occurs through various communica…