Artificial Neural Networks in archaeology

Artificial neural networks are adaptive models that can be used for classification and pattern recognition purposes. ANNs do not differ from standard statistical models. The main difference between ANNs and traditional statistical models is their construction and definition process. In fact ANNs are adaptive in the sense that they can learn. Landscape Archaeology is a research area where the application of ANNs can be very useful. ANNs can be used for Landscape pattern recognition and Settlement systems modeling. This paper illustrate some aspects of the development of new tools and the application of ANNs in a raster GIS environment for archaeological predictive modeling purposes

CAESAR: SEWGS integration into an IGCC plant

n/

Analyse chimique continue de la mer: II. Mission internationale <i>Mechelen</i> 1968 en Méditerranée

Results of automatic and continuous analysis of both physical and chemical parameters of sea water between Marbella (Malaga) and Brest (Mechelen cruise, Mediterranean 1968, supported by the « Institut royal des Sciences naturelles de Belgique ») are studied in this paper.Two conclusions are reached: 1° The distribution of salinity, temperature and nitrate, sometimes anomalous, appears to follow some rythm or law. 2° There appears a close spacial relationship too between these anomalies and fishery. Then, it is possible to use the continuous automatic method for the exploratory work on fishery technology

Surface Oscillations in Overdense Plasmas Irradiated by Ultrashort Laser Pulses

The generation of electron surface oscillations in overdense plasmas irradiated at normal incidence by an intense laser pulse is investigated. Two-dimensional (2D) particle-in-cell simulations show a transition from a planar, electrostatic oscillation at $2\omega$, with $\omega$ the laser frequency, to a 2D electromagnetic oscillation at frequency $\omega$ and wavevector $k>\omega/c$. A new electron parametric instability, involving the decay of a 1D electrostatic oscillation into two surface waves, is introduced to explain the basic features of the 2D oscillations. This effect leads to the rippling of the plasma surface within a few laser cycles, and is likely to have a strong impact on laser interaction with solid targets.Comment: 9 pages (LaTeX, Revtex4), 4 GIF color figures, accepted for publication in Phys. Rev. Let

Application of Hydrogen Selective Membranes to IGCC

AbstractThis study considers the integration of Pd-based H2-selective membranes in integrated gasifier combined cycles (IGCC) from both technical and economical point of view. The selected gasification system is based on Shell technology. Two different dry feeding systems are investigated: the first is a state-of-the- art nitrogen-based lock hopper charger while the second uses CO2 as pressurization gas. The net electric efficiency of the two plants is evaluated as a function of the hydrogen recovery factor (HRF) and the membrane feed pressure in order to minimize the membrane surface area. 90% HRF and 54bar feed pressure are the best operating parameters which correspond to a net electric efficiency of 39% both for N2 and CO2 feeding system. The cost of CO2 avoided is calculated as a function of a parameter named MI which represents the membrane development in terms of performances and costs. Results show that an improvement of membrane technology is necessary to match the state-of-the-art CO2 capture plant, even though membranes show good potentiality for cost abatement

Primeras descripciones de agregaciones pelágicas diurnas de langostino (Pleoticus muelleri) utilizando una ecosonda de banda ancha operando frecuencias múltiples

This is the first description of diurnal pelagic aggregations of the bottom-dwelling Argentine red shrimp (Pleoticus muelleri) registered with a broadband scientific echosounder. A pelagic trawl net and an underwater video camera were used to validate all the information presented in this paper. Shrimp aggregations were characterized by increasing frequency response, more evident at frequencies greater than 120 kHz. Identification of the acoustic signature of this resource is of particular interest for the development of new methodologies to complement the traditional swept area method of estimation.Reportamos la primera descripción de agregaciones pelágicas diurnas de langostino (Pleoticus muelleri) utilizando una ecosonda científica de banda ancha. Toda la información presentada en este manuscrito fue validada por medio de una red de arrastre pelágica y una cámara de video submarina. Las agregaciones de langostino se caracterizaron por poseer una respuesta en frecuencia creciente, siendo más evidente a frecuencias superiores a 120 kHz. La identificación de la firma acústica de las agregaciones pelágicas de langostino es de particular interés para el desarrollo de nuevas metodologías que complementen la evaluación tradicional de este recurso, realizada a través del método por área de barrida

Sensory Design in the Birth Environment: Learning from Existing Case Studies

Studies have shown how built environments for hospitals can influence psychological and physiological conditions and status for childbearing women. Sensory attributes of birth spaces can enhance comfort, feelings of wellbeing, and, to some extent, clinical outcomes. Recently, some case studies of multisensory rooms for the birth environment have been developed based on, e.g., Snoezelen room examples. The aim of this research is to develop an overview of how sensory aspects for birth environments are designed, used, and tested in current and recent studies. Case studies were selected according to sensory aspect significance, observing space factors, and relationship with the experience and comfort of users (women, partners, midwives). All case studies were analysed to collect information about the design and validation process. The collected data were organised in categories and compared for the selected case studies. Main findings were summarised in tables with the aim of underlining how sensory design processes and projects can positively influence comfort for birthing. Conclusions about how to bring forward the issue of sensory design so that it can be used and applied to support childbearing women is discussed

Ion dynamics and coherent structure formation following laser pulse self-channeling

The propagation of a superintense laser pulse in an underdense, inhomogeneous plasma has been studied numerically by two-dimensional particle-in-cell simulations on a time scale extending up to several picoseconds. The effects of the ion dynamics following the charge-displacement self-channeling of the laser pulse have been addressed. Radial ion acceleration leads to the ``breaking'' of the plasma channel walls, causing an inversion of the radial space-charge field and the filamentation of the laser pulse. At later times a number of long-lived, quasi-periodic field structures are observed and their dynamics is characterized with high resolution. Inside the plasma channel, a pattern of electric and magnetic fields resembling both soliton- and vortex-like structures is observed.Comment: 10 pages, 5 figures (visit http://www.df.unipi.it/~macchi to download a high-resolution version), to appear in Plasma Physics and Controlled Fusion (Dec. 2007), special issue containing invited papers from the 34th EPS Conference on Plasma Physics (Warsaw, July 2007

A Femtosecond Neutron Source

The possibility to use the ultrashort ion bunches produced by circularly polarized laser pulses to drive a source of fusion neutrons with sub-optical cycle duration is discussed. A two-side irradiation of a thin foil deuterated target produces two countermoving ion bunches, whose collision leads to an ultrashort neutron burst. Using particle-in-cell simulations and analytical modeling, it is evaluated that, for intensities of a few $10^{19} W cm^{-2}$, more than $10^3$ neutrons per Joule may be produced within a time shorter than one femtosecond. Another scheme based on a layered deuterium-tritium target is outlined.Comment: 15 pages, 3 figure