1,944 research outputs found
Efficacy and inefficacy of refrigerated storages on some physical, physiochemical and electrochemical properties for organically-grown ‘Royal Glory’ and ‘Redhaven’ peaches
The study focused on organically-grown ‘Royal Glory’ and ‘Redhaven’ peaches, with the aim to evaluate some physical, physiochemical and electrochemical quality indices during and after refrigerated storages at 0, 5 and 12 °C for up to 12 days and subsequently 1 day at 25 °C. Peaches lost their fresh weight and fi rmness during the storages regardless of the storage temperatures and cultivars; however, the loss in firmness for peaches at 12 °C was extensive, which delimited to durations of the storage. Marked changes in peel and flesh color, soluble solids content, titratable acidity, and vitamin C content were also registered over the storage time. Both cultivars developed chilling injury symptoms as internal flesh browning at 0 °C rather than at 5 °C which supported by a decrease in chromatic L* and b* values. For the fi rst time, electrochemical parameters such as redox potential and P-value for a peach fruit using Bioelectric Vincent method have been reported and evaluated. However, no significant relationship was found between electrochemical and other physiochemical quality parameters assessed
Disaster and fortune risk in asset returns
Do Disaster risk and Fortune risk fetch a premium or discount in the pricing of individual assets? Disaster risk and Fortune risk are measures for the co-movement of individual stocks with the market, given that the state of the world is extremely bad and extremely good, respectively. To address this question measures of Disaster risk and Fortune risk, derived from statistical Extreme Value Theory, are constructed. The measures are non-parametric and the number of order statistics to be used in the analysis is based on the Kolmogorov-Smirnov distance. This alleviates the problem of an arbitrarily chosen extreme region. The extreme dependence measures are used in Fama-MacBeth cross-sectional asset pricing regressions including Market, Fama-French, Liquidity and Momentum factors. I find that Disaster risk fetches a significant premium of 0.43% for the average stock
The drag force in two-fluid models of gas-solid flows
Currently, the two most widespread methods for modelling the particulate phase in numerical simulations of gas-solid flows are discrete particle simulation (see, e.g., Mikami, Kamiya, & Horio, 1998), and the two-fluid approach, e.g., kinetic theory models (see, e.g., Louge, Mastorakos, & Jenkins, 1991). In both approaches the gas phase is described by a locally averaged Navier-Stokes equation and the two phases are usually coupled by a drag force. Due to the large density difference between the particles and the gas, inter-phase forces other than the drag force are usually neglected, so it plays a significant role in characterising the gas-solid flow. Yasuna, Moyer, Elliott, and Sinclair (1995) have shown that the solution of their model is sensitive to the drag coefficient. In general, the performance of most current models depends critically on the accuracy of the drag force formulation
Dewatering of a Large Excavation Pit by Wellpoints
An excavation, rectangular in dimensions of 55 m x 95 m at the base and approximately 120 m x 160 m at the ground surface was made possible by the use of multi-staged wellpoint dewatering system. Groundwater table was lowered more than 20 meters using four stage wellpoint system to construct the main wastewater pump station for the city of Izmir. The most significant soil parameter affecting the planning and design of the dewatering work is the coefficient of field permeability, and it has been directly measured by a large scale pumping test at the site. During dewatering and construction stages, piezometers, inclinometers, extensometers and both conventional surveying and EDM methods were used. Total discharge rate was measured at different stages and it is compared with the theoretical approaches. Partial penetration factor for the well into aquifer is estimated
The role of web-based promotion on the development of a relationship marketing model to enable sustainable growth
AbstractIn recent years the web-based Relationship Marketing (RM) has been receiving a great attention from e-marketing perspective. The RM is evolved as a contemporary marketing initiative, which can be applied to all types of industries. Concurrently, because of the advancement of the Information Technology, web-based promotion and market offering are considered as dominating business development tool. From this context, five grown sporting cases have been analysed to realise how web-based promotion influences RM to develop a sustainable growth model, where the cases have been utilising the RM and web-based promotion lucratively to attain and retain the key stakeholders to sustain their growth. Following the initial literature review, the websites of the cases have been scrutinised thoroughly as data collection tool. Nineteen RM indicators are identified as different RM perspectives. The cases are positioning web-based promotions and offerings underlying these RM indicators as a combined promotional effort to enhance competitive advantage. From the case analysis, the concept of stakeholder causal scope is evolved as identical with this combined promotional effort, as well as proportionate with at least one of the four identified growth strategies. Finally, the RM centred ‘Sustainable Growth Model’ has been developed through the synthesis of the impact of the web-based RM indicator focused combined promotional effort of the cases on the associated stakeholder causal scopes and their relevancy with the growth strategies. Reinforcing the model is established significantly for marketers in various industries to enhance competitive advantage aiming to sustain organisational growth
The Effects of Turbulence on Three-Dimensional Magnetic Reconnection at the Magnetopause
Two- and three-dimensional particle-in-cell simulations of a recent encounter
of the Magnetospheric Multiscale Mission (MMS) with an electron diffusion
region at the magnetopause are presented. While the two-dimensional simulation
is laminar, turbulence develops at both the x-line and along the magnetic
separatrices in the three-dimensional simulation. The turbulence is strong
enough to make the magnetic field around the reconnection island chaotic and
produces both anomalous resistivity and anomalous viscosity. Each contribute
significantly to breaking the frozen-in condition in the electron diffusion
region. A surprise is that the crescent-shaped features in velocity space seen
both in MMS observations and in two-dimensional simulations survive, even in
the turbulent environment of the three-dimensional system. This suggests that
MMS's measurements of crescent distributions do not exclude the possibility
that turbulence plays an important role in magnetopause reconnection.Comment: Revised version accepted by GR
Double layers in the downward current region of the aurora
International audienceDirect observations of magnetic-field-aligned (parallel) electric fields in the downward current region of the aurora provide decisive evidence of naturally occurring double layers. We report measurements of parallel electric fields, electron fluxes and ion fluxes related to double layers that are responsible for particle acceleration. The observations suggest that parallel electric fields organize into a structure of three distinct, narrowly-confined regions along the magnetic field (B). In the "ramp" region, the measured parallel electric field forms a nearly-monotonic potential ramp that is localized to ~ 10 Debye lengths along B. The ramp is moving parallel to B at the ion acoustic speed (vs) and in the same direction as the accelerated electrons. On the high-potential side of the ramp, in the "beam" region, an unstable electron beam is seen for roughly another 10 Debye lengths along B. The electron beam is rapidly stabilized by intense electrostatic waves and nonlinear structures interpreted as electron phase-space holes. The "wave" region is physically separated from the ramp by the beam region. Numerical simulations reproduce a similar ramp structure, beam region, electrostatic turbulence region and plasma characteristics as seen in the observations. These results suggest that large double layers can account for the parallel electric field in the downward current region and that intense electrostatic turbulence rapidly stabilizes the accelerated electron distributions. These results also demonstrate that parallel electric fields are directly associated with the generation of large-amplitude electron phase-space holes and plasma waves
Fundamental length in quantum theories with PT-symmetric Hamiltonians II: The case of quantum graphs
Manifestly non-Hermitian quantum graphs with real spectra are introduced and
shown tractable as a new class of phenomenological models with several
appealing descriptive properties. For illustrative purposes, just equilateral
star-graphs are considered here in detail, with non-Hermiticities introduced by
interactions attached to the vertices. The facilitated feasibility of the
analysis of their spectra is achieved via their systematic approximative
Runge-Kutta-inspired reduction to star-shaped discrete lattices. The resulting
bound-state spectra are found real in a discretization-independent interval of
couplings. This conclusion is reinterpreted as the existence of a hidden
Hermiticity of our models, i.e., as the standard and manifest Hermiticity of
the underlying Hamiltonian in one of less usual, {\em ad hoc} representations
of the Hilbert space of states in which the inner product is local
(at ) or increasingly nonlocal (at ). Explicit examples of
these (of course, Hamiltonian-dependent) hermitizing inner products are offered
in closed form. In this way each initial quantum graph is assigned a menu of
optional, non-equivalent standard probabilistic interpretations exhibiting a
controlled, tunable nonlocality.Comment: 33 pp., 6 figure
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