EXPERIMENTAL VALIDATION OF A DYNAMIC MODEL FOR A RESIDENTIAL HEAT PUMP WITH IMMERSED CONDENSER

This work describes the validation of a dynamic model for a vapor compression residential heat pump with an immersed condenser. A detailed description of the modelling methodology for each component (compressor, capillary tube, evaporator, and immersed condenser) and the solution methodology employed in the complete heat pump system are presented. The main contribution of this work is in the dynamic modeling of the thermal processes occurring within the heat exchangers. Instabilities of the solutions for the heat exchangers are minimized by considering spatially and temporal varying errors. Another contribution of the model is the investigation of the temperature distribution inside the water storage tank, which highlights the possibility of using immersed condensers for this purpose without significant thermal stratification in the tank. Simulation results and experimental results are compared for transient operations using multivariate profiles of temperature, pressure and mass flow rates in heat exchangers during the water heating process

Non-universal behavior for aperiodic interactions within a mean-field approximation

We study the spin-1/2 Ising model on a Bethe lattice in the mean-field limit, with the interaction constants following two deterministic aperiodic sequences: Fibonacci or period-doubling ones. New algorithms of sequence generation were implemented, which were fundamental in obtaining long sequences and, therefore, precise results. We calculate the exact critical temperature for both sequences, as well as the critical exponent $\beta$, $\gamma$ and $\delta$. For the Fibonacci sequence, the exponents are classical, while for the period-doubling one they depend on the ratio between the two exchange constants. The usual relations between critical exponents are satisfied, within error bars, for the period-doubling sequence. Therefore, we show that mean-field-like procedures may lead to nonclassical critical exponents.Comment: 6 pages, 7 figures, to be published in Phys. Rev.

The role of brand equity in a new rebranding strategy of a private label brand

The purpose of this study is to understand the effects of the rebranding process on private label performance output, namely, on brand equity. More specifically, the study aims to investigate the performance of brand equity constructs (brand awareness, brand associations, perceived quality and brand loyalty) before and after the rebranding process. A questionnaire was administered to 466 shoppers, who put forth their perceptions, of the brand’s image, before and after the rebranding. When analyzed altogether, brand equity constructs have not suffered significant changes, meaning that previously existing brand equity had successfully been transferred onto the new brand; however, new brand equity was not created in the process. Consumers do still associate the private label brand image with its previous brand identity. Nevertheless, their ability to easily identify the various brand tiers was improved with the new image. Consumers associate the rebranded image with being “innovative” and “original” and describe the previous image as “inexpensive” and “trustworthy”. Brand awareness and loyalty are the factors that relate the most to consumers’ perceptions of the brand before its rebranding. This study contributes to the brand management literature by providing a new look into the under-researched problem of rebranding and brand equity, empirically validating the real-life market case.info:eu-repo/semantics/acceptedVersio

Toward a test of angular momentum coherence in a twin-atom interferometer

We present a scheme well-suited to investigate quantitatively the angular momentum coherence of molecular fragments. Assuming that the dissociated molecule has a null total angular momentum, we investigate the propagation of the corresponding atomic fragments in the apparatus. We show that the envisioned interferometer enables one to distinguish unambiguously a spin-coherent from a spin-incoherent dissociation, as well as to estimate the purity of the angular momentum density matrix associated with the fragments. This setup, which may be seen as an atomic analogue of a twin-photon interferometer, can be used to investigate the suitability of molecule dissociation processes -- such as the metastable hydrogen atoms H($2^2 S$)-H($2^2 S$) dissociation - for coherent twin-atom optics.Comment: 6 pages, 3 Figures. Final version accepted for publication in Europhysics Letter