Higher-order mutual coherence of optical and matter waves

We use an operational approach to discuss ways to measure the higher-order cross-correlations between optical and matter-wave fields. We pay particular attention to the fact that atomic fields actually consist of composite particles that can easily be separated into their basic constituents by a detection process such as photoionization. In the case of bosonic fields, that we specifically consider here, this leads to the appearance in the detection signal of exchange contributions due to both the composite bosonic field and its individual fermionic constituents. We also show how time-gated counting schemes allow to isolate specific contributions to the signal, in particular involving different orderings of the Schr\"odinger and Maxwell fields.Comment: 11 pages, 2 figure

Generation of atom-photon entangled states in atomic Bose-Einstein condensate via electromagnetically induced transparency

In this paper, we present a method to generate continuous-variable-type entangled states between photons and atoms in atomic Bose-Einstein condensate (BEC). The proposed method involves an atomic BEC with three internal states, a weak quantized probe laser and a strong classical coupling laser, which form a three-level Lambda-shaped BEC system. We consider a situation where the BEC is in electromagnetically induced transparency (EIT) with the coupling laser being much stronger than the probe laser. In this case, the upper and intermediate levels are unpopulated, so that their adiabatic elimination enables an effective two-mode model involving only the atomic field at the lowest internal level and the quantized probe laser field. Atom-photon quantum entanglement is created through laser-atom and inter-atomic interactions, and two-photon detuning. We show how to generate atom-photon entangled coherent states and entangled states between photon (atom) coherent states and atom-(photon-) macroscopic quantum superposition (MQS) states, and between photon-MQS and atom-MQS states.Comment: 9 pages, 1 figur

Integrating fiscal issues in global distribution network design

Global distribution network design (GDND) is currently facing a phase of substantial changes, since logistics decisions need to consider also fiscal and legal aspects. Although the adoption of an integrated approach may create new opportunities for GDND, logistics and fiscal domains are based on different principles and frictions may arise, creating distortions in the optimal logistics configuration and eventually involving cross-country flows. This issue is still under-represented in the academic literature, despite the rising debate in the practitioners’ community. The purpose of this paper is to fill this gap by investigating the available configurations in GDND, focusing on a location problem for a single distribution layer. A multinational corporation (MNC) may consider shifting the optimal logistics location of a central warehouse (CW) in a close low-tax jurisdiction, although additional cross-border transports may occur. A three-phase methodology was adopted. First, available cross-country logistics configurations were formalised and modelled by means of interviews with MNCs. Then, a cost-based model was developed, combining logistics and fiscal cost functions, with the aim of maximising after-taxes bottom-line results. The model was applied to a MNC willing to distribute in the European market from a Swiss warehouse. A sensitivity analysis was performed, varying annual demand, product value, operating expenses, exchange rate and Swiss corporate tax rate. Results confirmed the impact of taxation on GDND, and highlighted the importance of including fiscal issues when designing global distribution networks. A cross-country logistics configuration may turn out as the most suitable, if the reduction in corporate income taxes overcomes the increase in logistics cost, and corporate tax rate emerges as the main element driving network design

EUReCA: An open-source urban building energy modelling tool for the efficient evaluation of cities energy demand

Recently, the attention towards Urban Building Energy Modelling has been growing due to the large contribution of cities on the worldwide energy consumption rate. In fact, many models have been developed to simulate buildings and urban energy systems. This article presents a new open-source tool for city-scale simulations. The platform implements the electrical analogy to model buildings thermal behaviour through resistance-capacitance networks, thus predicting the energy demand of urban areas with a bottom-up approach and low computational resources. The model has been applied to two urban areas: a small and well-known neighbourhood and a broader urban district. Results show the accordance of simplified models with respect to single building detailed simulations in the evaluation of the seasonal energy demand. When comparing results at hourly resolution, the accuracy is increased by considering a thermal network that splits buildings\u2019 surfaces into two capacitances. A model based on a single capacitance leads to a higher deviation, especially on the daily peak power. Regarding the district simulation, these simplified networks show a good prediction of the buildings energy demand according to relevant European references, thus demonstrating the reliability of the proposed approach despite their low computational effort

Maturation of Eugenia pyriformis seeds under different hydric and thermal conditions

O presente estudo tem como objetivo analisar a maturação e a dispersão de sementes de Eugenia pyriformis Cambess. produzidas em diferentes anos, verificando a influência das variações hídricas e térmicas do ambiente sobre suas características físicas e fisiológicas no momento em que são dispersas. Frutos com diferentes estágios de desenvolvimento foram coletados da região de São Paulo, entre 2003 e 2010 e das regiões de Campinas e Lavras, em 2009 e 2010 e foram analisados quanto ao tamanho e à cor. As sementes foram extraídas dos frutos e analisadas quanto ao conteúdo de massa seca, teor de água, germinação e vigor. Os resultados evidenciaram que a maturação das sementes ocorre de forma dessincronizada à maturação dos frutos, levando em média 45 dias (430 graus-dia), sendo mais demorada em períodos chuvosos ou de temperaturas mais baixas. Sementes de qualidade fisiológica mais elevada foram produzidas em anos chuvosos e quando a amplitude térmica foi maior. Conclui-se, portanto, que as variações hídricas e térmicas do ambiente e do período de formação influenciam sobre a maturação das sementes de uvaieira podendo, inclusive, determinar o ciclo de formação e a qualidade final dessas sementes.This study aims to analyze the maturation and dispersal of Eugenia pyriformis Cambess. seeds produced in different years, and the influence of variation in thermal and hydric environment on seed physical and physiological characteristics at dispersal. Fruits at different developmental stages were harvested in the city of São Paulo between 2003 and 2010, as well as in the cities of Campinas and Lavras, in 2009 and 2010 and analyzed for size and color. The seeds were extracted from the fruits and their dry mass, water content, germination and vigor were assessed. Results showed that seed maturation is unsynchronized to the maturation of the fruit, taking 45 days on average (430 growing degree-days), longer in rainy times or lower temperatures. Seeds with higher physiological quality were produced in rainy years and when the temperature range was larger. We concluded therefore that hydric and thermal environmental variations during development influence the maturation of Eugenia pyriformis seeds and are able to determine the formation cycle and the final seed quality.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP