Repeat Buying Behavior for Ornamental Plants: A Consumer Profile

The main objective of this research was to study what stimulates repeat buying behavior for ornamental plants by segmenting consumer demographics and other important variables in the purchasing decision for ornamental plants. Specifically, we looked at the number of transactions per month as a function of the purpose of the purchase. Consumer’s behavioral and socio-demographic characteristics that are more likely to influence the number of ornamental transactions were also identified.Green Industry, flower demand, consumer preferences, Consumer/Household Economics, Marketing, M31, R22,

A Nonequilibrium Finite-Rate Carbon Ablation Model for Radiating Earth Re-entry Flows

Vehicles entering planetary atmospheres at high speed require an ablative heat shield in order to withstand the high thermal energy flux to the body. The interaction between the ablative products and the flow field is not well characterized. Numerical simulations were conducted to investigate the influence of carbon ablation on shock layer radiation. Data collected from experiments performed in the X-2 expansion tunnel at the University of Queensland was used to compare to the simulations. The model was a short half-cylinder made of isomolded graphite and was tested in 8.6 km/s Earth entry flow. The model surface was heated within a temperature range of 1770-3280 K. The radiation emitted from the CN violet bands was measured by ultraviolet spectrometry in a spectral range from 353-391 nm. This research develops a novel finite-rate surface kinetic model for determining the chemical state of an ablating boundary layer. The proposed ablation model accounts for competing surface reaction processes such as adsorption/desorption, Eley-Rideal mechanisms, oxidation, nitridation, and sublimation. The included oxidation mechanisms predict CO as the primary oxidized product at the considered surface temperatures, which is in agreement with experiment and theory. A previous model had incorrectly predicted CO2 as the primary oxidized product for a majority of the tested surface temperatures. The ablative gas species predicted by this new surface model results in better agreement with experimental spectral measurements than predictions provided by legacy ablation models, and represents a significant improvement in current modeling capabilities for hypersonic nonequilibrium ablating re-entry flows

Discrete breathers for understanding reconstructive mineral processes at low temperatures

Reconstructive transformations in layered silicates need a high tem- perature in order to be observed. However, very recently, some systems have been found where transformation can be studied at temperatures 600 C below the lowest experimental results previously reported, including sol-gel methods. We explore the possible relation with the existence of intrinsic localized modes, known as discrete breathers. We construct a model for nonlinear vibrations within the cation layer, obtain their parameters and calculate them numerically, obtaining their energies. Their statistics shows that although there are far less breathers than phonons, there are much more above the activation energy, being therefore a good candidate to explain the reconstructive transformations at low temperature.Comment: 27 pages, 11 figure

Binary Search Algorithm for Mixed Integer Optimization: Application to energy management in a microgrid

This paper presents a binary search algorithm to deal with binary variables in mixed integer optimization problems. One example of this kind of problem is the optimal operation of hydrogen storage and energy sale and purchase into a microgrids context. In this work was studied a system composed by a microgrid that has a connection with the external electrical network and a charging station for electric cars. The system modeling was carried out by the Energy Hubs methodology. The proposed algorithm transforms the MIQP (Mixed Integer Quadratic Program) problem into a QP (Quadratic Program) that is easier to solve. In this way the overall control task is carried out the electricity purchase and sale to the power grid, maximizes the use of renewable energy sources, manages the use of energy storages and supplies the charge of the parked vehicles.Ministerio de Economía y Competitividad DPI2013-46912-C2-1-RUniversidad de Sevilla CNPq401126/2014-5Universidad de Sevilla CNPq303702/2011-

The Chrono-geometrical Structure of Special and General Relativity: a Re-Visitation of Canonical Geometrodynamics

A modern re-visitation of the consequences of the lack of an intrinsic notion of instantaneous 3-space in relativistic theories leads to a reformulation of their kinematical basis emphasizing the role of non-inertial frames centered on an arbitrary accelerated observer. In special relativity the exigence of predictability implies the adoption of the 3+1 point of view, which leads to a well posed initial value problem for field equations in a framework where the change of the convention of synchronization of distant clocks is realized by means of a gauge transformation. This point of view is also at the heart of the canonical approach to metric and tetrad gravity in globally hyperbolic asymptotically flat space-times, where the use of Shanmugadhasan canonical transformations allows the separation of the physical degrees of freedom of the gravitational field (the tidal effects) from the arbitrary gauge variables. Since a global vision of the equivalence principle implies that only global non-inertial frames can exist in general relativity, the gauge variables are naturally interpreted as generalized relativistic inertial effects, which have to be fixed to get a deterministic evolution in a given non-inertial frame. As a consequence, in each Einstein's space-time in this class the whole chrono-geometrical structure, including also the clock synchronization convention, is dynamically determined and a new approach to the Hole Argument leads to the conclusion that "gravitational field" and "space-time" are two faces of the same entity. This view allows to get a classical scenario for the unification of the four interactions in a scheme suited to the description of the solar system or our galaxy with a deperametrization to special relativity and the subsequent possibility to take the non-relativistic limit.Comment: 33 pages, Lectures given at the 42nd Karpacz Winter School of Theoretical Physics, "Current Mathematical Topics in Gravitation and Cosmology", Ladek, Poland, 6-11 February 200

IGFBP-3 inhibits Wnt signaling in metastatic melanoma cells.

In previous works, we have shown that insulin-like growth factor-binding protein-3 (IGFBP-3), a tissue and circulating protein able to bind to IGFs, decreases drastically in the blood serum of patients with diffuse metastatic melanoma. In agreement with the clinical data, recombinant IGFBP-3 was found to inhibit the motility and invasiveness of cultured metastatic melanoma cells and to prevent growth of grafted melanomas in mice. The present work was aimed at identifying the signal transduction pathways underlying the anti-tumoral effects of IGFBP-3. We show that the anti-tumoral effect of IGFBP-3 is due to inhibition of the Wnt pathway and depends upon the presence of CD44, a receptor protein known to modulate Wnt signaling. Once it has entered the cell, IGFBP-3 binds the Wnt signalosome interacting specifically with its component GSK-3β. As a consequence, the β-catenin destruction complex dissociates from the LRP6 Wnt receptor and GSK-3β is activated through dephosphorylation, becoming free to target cytoplasmic β-catenin which is degraded by the proteasomal pathway. Altogether, the results suggest that IGFBP-3 is a novel and effective inhibitor of Wnt signaling. As IGFBP-3 is a physiological protein which has no detectable toxic effects either on cultured cells or live mice, it might qualify as an interesting new therapeutic agent in melanoma, and potentially many other cancers with a hyperactive Wnt signaling

Drivers of Business-to-Business (B2B) Sales Success and the role of Digitalization after COVID-19 Disruptions

Purpose - The purpose of this research is to investigate the drivers of business-to-business sales success and the role of digitalization, in a selling and sales management landscape being disrupted by COVID-19. Design/methodology/approach – The methodology follows a discovery-oriented grounded theory approach which consists of a two-stage qualitative study with sales professionals in Chile, and a Fuzzy-Set Qualitative Comparative Analysis (fsQCA). Findings - This research shows that interfunctional coordination, agility in the selling process, and business customer engagement are critical determinants of B2B sales success, while digitalization moderates these relationships. Originality/value - This research responds to a call for more research on the impact of digitalization on business relationships in different contexts and perspectives. We study the Chilean context, through a two-stage qualitative study, and a fsQCA analysis, which constitutes a novel combination in this stream of research