Absolute spectral gaps for infrared light and hypersound in three-dimensional metallodielectric phoxonic crystals

By means of full electrodynamic and elastodynamic multiple-scattering calculations we study the optical and acoustic properties of three-dimensional lattices of metallic nanospheres implanted in a dielectric host. Our results show that such structures exhibit omnidirectional spectral gaps for both telecom infrared light and hypersound, with relatively low absorptive losses. This class of dual phoxonic band-gap materials is an essential step toward the hypersonic modulation of light and could lead to the development of efficient acousto-optical devices

Energy efficiency parametric design tool in the framework of holistic ship design optimization

Recent International Maritime Organization (IMO) decisions with respect to measures to reduce the emissions from maritime greenhouse gases (GHGs) suggest that the collaboration of all major stakeholders of shipbuilding and ship operations is required to address this complex techno-economical and highly political problem efficiently. This calls eventually for the development of proper design, operational knowledge, and assessment tools for the energy-efficient design and operation of ships, as suggested by the Second IMO GHG Study (2009). This type of coordination of the efforts of many maritime stakeholders, with often conflicting professional interests but ultimately commonly aiming at optimal ship design and operation solutions, has been addressed within a methodology developed in the EU-funded Logistics-Based (LOGBASED) Design Project (2004–2007). Based on the knowledge base developed within this project, a new parametric design software tool (PDT) has been developed by the National Technical University of Athens, Ship Design Laboratory (NTUA-SDL), for implementing an energy efficiency design and management procedure. The PDT is an integral part of an earlier developed holistic ship design optimization approach by NTUA-SDL that addresses the multi-objective ship design optimization problem. It provides Pareto-optimum solutions and a complete mapping of the design space in a comprehensive way for the final assessment and decision by all the involved stakeholders. The application of the tool to the design of a large oil tanker and alternatively to container ships is elaborated in the presented paper

Christianity, Democracy, and the Shadow of Constantine

The collapse of communism in eastern Europe has forced traditionally Eastern Orthodox countries to consider the relationship between Christianity and liberal democracy. Contributors examine the influence of Constantinianism in both the post-communist Orthodox world and in Western political theology. Constructive theological essays feature Catholic and Protestant theologians reflecting on the relationship between Christianity and democracy, as well as Orthodox theologians reflecting on their tradition’s relationship to liberal democracy. The essays explore prospects of a distinctively Christian politics in a post-communist, post-Constantinian age

Acousto-optic interaction enhancement in dual photonic-phononic cavities

Light control through elastic waves is a well established and mature technology. The underlying mechanism is the scattering of light due to the dynamic modulation of the refractive index and the material interfaces caused by an elastic wave, the so-called acousto-optic interaction. This interaction can be enhanced in appropriately designed structures that simultaneously localize light and elastic waves in the same region of space and operate as dual optical-elastic cavities, often called phoxonic or optomechanical cavities. Typical examples of phoxonic cavities are multilayer films with a dielectric sandwiched between two Bragg mirrors or, in general, defects in macroscopically periodic structures that exhibit dual band gaps for light and elastic waves. In the present work we consider dielectric particles as phoxonic cavities and study the influence of elastic eigenmode vibrations on the optical Mie resonances. An important issue is the excitation of elastic waves in such submicron particles and, in this respect, we analyze the excitation of high-frequency vibrations following thermal expansion induced by the absorption of a femtosecond laser pulse. For spherical particles, homogeneous thermalization leads to excitation of the particle breathing modes. We report a thorough study of the acousto-optic interaction, correct to all orders in the acousto-optic coupling parameter, by means of rigorous full electrodynamic and elastodynamic calculations, in both time and frequency domains. Our results show that, under double elastic-optical resonance conditions, strong acousto-optic interaction takes place and results in large dynamical shifts of the high-Q optical Mie resonances, manifested through multiphonon exchange mechanisms

Sequential Experimental Design for Predator-Prey Functional Response Experiments

Understanding functional response within a predator-prey dynamic is a cornerstone for many quantitative ecological studies. Over the past 60 years, the methodology for modelling functional response has gradually transitioned from the classic mechanistic models to more statistically oriented models. To obtain inferences on these statistical models, a substantial number of experiments need to be conducted. The obvious disadvantages of collecting this volume of data include cost, time and the sacrificing of animals. Therefore, optimally designed experiments are useful as they may reduce the total number of experimental runs required to attain the same statistical results. In this paper, we develop the first sequential experimental design method for predator-prey functional response experiments. To make inferences on the parameters in each of the statistical models we consider, we use sequential Monte Carlo, which is computationally efficient and facilitates convenient estimation of important utility functions. It provides coverage of experimental goals including parameter estimation, model discrimination as well as a combination of these. The results of our simulation study illustrate that for predator-prey functional response experiments sequential design outperforms static design for our experimental goals. R code for implementing the methodology is available via https://github.com/haydenmoffat/sequential_design_for_predator_prey_experiments.Comment: Main Text: 23 pages, 7 Figures - Supplementary Text: 11 pages, 5 Figure

GEOTHERMIC STATUS OF THERMOPYLAE - ANTHILI AREA IN FTHIOTIDA PREFECTURE

The purpose of this study was the discovery, identification and evaluation of directly exploitable geothermal fields, in the Thermopylae - Anthili area (100km2 ). After the evaluation and the processing of any preexisting data, followed the surface works, such as further geological mapping, tectonic and stratigraphic correlations and analyses, geothermal impressions, observations at 30 recorded points (springs, drillings, wells) regarding water sampling, chemical analyses, temperature, pH and conductivity measurements, special sampling for Br and isotopes analyses. The in depth works that took place concern geophysical prospecting, loggings, small and large diameter drillings. All the data were digitized and processed in a GIS environment. After correlating all the data collected for the region, a geological - geothermal model was constructed. According to this model, water percolates through permeable formations, joints and faults, gets mixed with the existing salt water, warms up and then ascends to the surface through faults and concentrates on proper reservoirs. Specifically, the region of Damasta where two areas of hot water reservoirs have been identified is of particular geothermal interest. The first, located in Triassic– Jurassic limestones (more than 600m deep), presents the greatest interest in terms of temperature and capacity, while the second (found on the surface and up to 350m deep) is located in Quaternary sediments and the upper formations of the underlying Late Cretaceous limestone