Search results for "SPACE"

On the effects of suitably designed space microstructures in the propagation of waves in time modulated composites

2023

In the one-dimensional case, the amplitude of a pulse that propagates in a homogeneous material whose properties are instantaneously changed in time will undergo an exponential increase due to the interference between the reflected and transmitted pulses generated at each sudden switch. Here, we resolve the issue by designing suitable reciprocal PT-symmetric space-time microstructures so that the interference between the scattered waves is such that the overall amplitude of the wave will be constant in time in each constituent material. Remarkably, for the geometries proposed here, a pulse will propagate with constant amplitude regardless of the impedance between the constituent materials,…

Nonparametric intensity estimation in space-time point processes and application to seismological problems

2008

Missing Data in Space-time: Long Gaps Imputation Based On Functional Data Analysis

2017

High dimensional data with spatio-temporal structures are of great interest in many elds of research, but their exhibited complexity leads to practical issues when formulating statistical models. Functional data analysis through smoothing methods is a proper framework for incorporating space-time structures: extending the basic methodology to the multivariate spatio-temporal setting, we refer to Generalized Additive Models for estimating functional data taking the spatial and temporal dependences into account, and to Functional Principal Component Analysis as a classical dimension reduction technique to cope with the high dimensionality and with the number of estimated eects. Since spatial …

Exploring mobilities in time and space

2013

Spazio e lingua nella 'costruzione' greca dell'identità etnica. Alcune osservazioni a partire da Erodoto

2018

The paper aims to offer an account of some representative opinions of ancient Greeks about the role of the space, conceived in its geographical/environmental value, in which a certain population lives, as well as of the language spoken by a population, in order to build historically the concept of Greek nation (to Hellenikón). The different positions expressed on these matters by Herodotus, Thucydides, Strabon and Pausanias are discussed, and the examination mostly concernes the ethnic and historical-linguistic aspects of the representation of the Dorians and Ionians.

Modelling flow and heat transfer in spacer-filled membrane distillation channels using open source CFD code

2013

Abstract A good understanding of the details of hydrodynamic and heat transport conditions and their impact on temperature polarisation and pressure drops is essential for optimum design of membrane distillation (MD) modules. To this end, the present work reports on initial progress in the development of a tool for 3D simulation of spacer-filled MD channels based on the open source CFD code library OpenFOAM. The paper discusses a number of modelling and implementation aspects including model geometry and computational domain, choice of boundary conditions, and discretisation schemes. The results pertaining to the effect of three different spacer types on the fluid dynamics and heat transfer…

Friction and Heat Transfer in Membrane Distillation Channels: An Experimental Study on Conventional and Novel Spacers

2022

The results of an experimental investigation on pressure drop and heat transfer in spacer-filled plane channels, which are representative of Membrane Distillation units, are presented and discussed. Local and mean heat transfer coefficients were obtained by using Thermochromic Liquid Crystals and Digital Image Processing. The performances of a novel spacer geometry, consisting of spheres that are connected by cylindrical rods, and are hereafter named spheres spacers, were compared with those of more conventional woven and overlapped spacers at equal values of the Reynolds number Re (in the range ~150 to ~2500), the pitch-to-channel height ratio, the flow attack angle and the thermal boundar…

Space-Time Forecasting of Seismic Events in Chile

2017

The aim of this work is to study the seismicity in Chile using the ETAS (epidemic type aftershock sequences) space‐time approach. The proposed ETAS model is estimated using a semi‐parametric technique taking into account the parametric and nonparametric components corresponding to the triggered and background seismicity, respectively. The model is then used to predict the temporal and spatial intensity of events for some areas of Chile where recent large earthquakes (with magnitude greater than 8.0 M) occurred.

Prekäre Räume

2020

Recent events in the Mediterranean call up for a radical questioning of our categories and representations. Sinking boats and emergency landings, reception policies and detention centres, crossings, deviations and refoulements symbolize an era when mobility is fatally related to security policies and new biopolitical regimes. Migrant bodies crossing the Mediterranean address a demand and a challenge that cultural geography is urged to accomplish. The aim of this paper is therefore to rethink spatiality in an ethical sense. Drawing on the philosophy of Emmanuel Lévinas and Judith Butler, we will try to imagine a new spatiality starting from bodies, displacements, and the complex open weave p…

The Influence of the Cross-Border Infrastructure Corridor on the Development of Medium-Sized Upper Silesian Cities on the Example of Bohumm and Jastr…

2018

The southern part of the A1 motorway (D1 in Czech designation) is a functioning infrastructure corridor connecting the Czech and Polish parts of the Upper Silesian Agglomeration, which is significant for the development of medium-sized cities in this region. This article is a continuation of research that was conducted in 2013. A research on Czech Bohumin and Polish Jastrzębie Zdrój was repeated with regard to the developmental aspects of these two medium-sized cities in the context of the functioning A1 motorway. The changes that have taken place in recent years in the spatial structure of the mentioned cities have been analysed. Research and analyses were conducted using ArcGIS software o…