568 research outputs found

    Customers’ experiences of fast food delivery services: uncovering the semantic core benefits, actual and augmented product by text mining

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    Purpose This study conceptualizes food delivery services as service mix decisions (SMDs) and illustrates a data-driven approach for the analysis of customers' written experiences. Design/methodology/approach Web scraping, text mining techniques as well as multivariate statistics are combined to uncover the structure of the three tiers of SMD from consumers' point of view. Findings The analyses reveal that fast food delivery is not primarily about speed but that there are four distinct experiential factors to be considered for SMDs. Fast food delivery services are associated both with the actual product (i.e. product issues and brand satisfaction) and with the augmented product (payment process and service handling). Originality/value Findings demonstrate the relevance of SMDs in omnichannel food retail environments and guide researchers in multistage analyses of consumers' online food reviews

    Modelling applications of photonic bandgap fibres

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    Photonic crystal fibres (PCFs)[1] are one of the most exciting developments in the field of photonics that has emerged in recent years. Not only have they already led to cheap all-fibre high brightness white light sources and have sparked a renaissance in the field of nonlinear optics but they also have the potential to dramatically change the next generation of telecommunication systems. PCFs can be split into two categories, the first have a solid core and guide light by modified total internal reflection, while the second photonic bandgap fibres (PBF) guide light by photonic bandgap effects and typically have a low index core compared to the cladding. Also of interest are "arrow" fibres which have a solid core and guide light due to the arrangement of high index defects in the cladding. In this paper we will be concentrating on designing and manipulating the properties of PBFs. etc..

    ÍNDICES DE SELECCIÓN EN GANADO BRAUNVIEH EN MÉXICO USANDO METODOLOGÍA DE GANANCIA DESEADA

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    Selection indexes were developed for productive and reproductive characteristics of Braunvieh cattle in México, through the desired gain procedure.Se desarrollaron índices de selección para rasgos productivos y reproductivos de ganado Braunvieh en México, mediante el procedimiento de ganancia deseada. Los datos para este estudio fueron obtenidos de la Asociación Mexicana de Ganado Braunvieh

    Preparación, caracterización y estudios texturales de carbones activados obtenidos a partir de yerba mate y su utilización para la remoción de fenol y Cr (III) en solución acuosa

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    Se sintetizaron carbones activados partiendo de yerba mate con distintos tratamientos químicos y físicos y se los estudió para la remoción de fenol y Cr(III) en soluciones acuosas. Se realizó la caracterización textural de los materiales carbonosos y se calculó área específica BET; volumen, tamaño y distribución tamaños de poros y posibles heterogeneidades de la superficie, empleandoteoría de funcionales de densidad (NL/QSDFT); tipoy cantidad de grupos oxigenados superficiales por el método de Boehm; punto de carga cero; microscopía electrónica de barrido y espectroscopia infrarroja por transformada de Fourier en celda de reflectancia difusa. Los datos experimentales de la adsorción de fenoly Cr(III) en solución acuosa fueron interpretados empleando modelo de Sips. El mayor área superficial corresponde a la muestra CYMFQ con 454 m2.g-1. CYMF resultó ser la más adecuada para la remoción de fenol, con capacidad máxima de 0.0040 mol.g-1. CYMFQ resultó ser la más adecuada para la remoción de cromo con capacidad máxima de 9.66 mg.g-1

    Simulación de gases en cámaras de almacenamiento de fruta

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    Simulation of Gases in Fruit Cold Storage Chambers: Nowadays there is an increasing use of low Oxygen (LO) and ultra low Oxygen (ULO) atmospheres for long term cold storage of fruits. Some physiological disorders associated with these postharvest technologies point to the presence of small spatial gradients in gas concentration as the major cause. However, it is extremely difficult to perform experimental tests measuring spatial gas gradients with sufficient resolution. In this study a spatiotemporal gas simulation software has been developed as a decision tool with the aim to evaluate various stowage and fruit conditions, as well as containers design

    Lattice gas and lattice Boltzman for spatio-temporal simulation of gases in fruit storage chambers

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    The benefit of controlled and modified atmospheres for extending the storage life of fruits is world wide accepted. However, there are secondary effects such as the incidence of anaerobic respiration or the off-favour occurrence which are not sufficiently known and thus controlled. This study approaches the knowledge of those secondary effects by developing a spatio temporal model gathering fluid flow phenomenon and physic and physiological processes. The lattice Boltzmann model used as framework for mimicking the fluid flow shows to be a very flexible tool which reproduces complex macroscopic behaviours on a down up strategy better than Lattice Gas Cellular Automata (LGCA

    Crack initiation and propagation on the polymeric material ABS (Acrylonitrile Butadiene Styrene), under ultrasonic fatigue testing

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    Crack initiation and propagation have been investigated on the polymeric material ABS (Acrylonitrile Butadiene Styrene), under ultrasonic fatigue testing. Three controlled actions were implemented in order to carry out fatigue tests at very high frequency on this material of low thermal conductivity, they are: a) The applying load was low to limit heat dissipation at the specimen neck section, b) The dimensions of testing specimen were small (but fitting the resonance condition), in order to restraint the temperature gradient at the specimen narrow section, c) Temperature at the specimen neck section was restrained by immersion in water or oil during ultrasonic fatigue testing. Experimental results are discussed on the basis of thermo-mechanical behaviour: the tail phenomenon at the initial stage of fatigue, initial shear yielding deformation, crazed development on the later stage, plastic strain on the fracture surface and the transition from low to high crack growth rate. In addition, a numerical analysis is developed to evaluate the J integral of energy dissipation and the stress intensity factor K, with the crack lengt

    A lattice model for the kinetics of rupture of fluid bilayer membranes

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    We have constructed a model for the kinetics of rupture of membranes under tension, applying physical principles relevant to lipid bilayers held together by hydrophobic interactions. The membrane is characterized by the bulk compressibility (for expansion), the thickness of the hydrophobic part of the bilayer, the hydrophobicity and a parameter characterizing the tail rigidity of the lipids. The model is a lattice model which incorporates strain relaxation, and considers the nucleation of pores at constant area, constant temperature, and constant particle number. The particle number is conserved by allowing multiple occupancy of the sites. An equilibrium ``phase diagram'' is constructed as a function of temperature and strain with the total pore surface and distribution as the order parameters. A first order rupture line is found with increasing tension, and a continuous increase in proto-pore concentration with rising temperature till instability. The model explains current results on saturated and unsaturated PC lipid bilayers and thicker artificial bilayers made of diblock copolymers. Pore size distributions are presented for various values of area expansion and temperature, and the fractal dimension of the pore edge is evaluated.Comment: 15 pages, 8 figure
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