Development of multi-criteria decision support system (DSS) coupled with GIS for identifying optimal locations for soil aquifer treatment (SAT) facilities

Η διαχείριση του εμπλουτισμού των υδροφορέων αποτελεί μια ευρέως διαδομένη τεχνική, ιδιαίτερα σε υδρολογικά ευαίσθητες περιοχές, όπως αυτές της Μεσογειακής Λεκάνης, όπου οι υδατικοί πόροι είναι περιορισμένοι. Η επιλογή της χωροθέτησης έργων τεχνητού εμπλουτισμού (Τ.Ε.) αποτελεί μια πολύπλοκη διαδικασία το αποτέλεσμα της οποίας καθορίζει εν πολλοίς και την ίδια την αποτελεσματικότητα του έργου. Η εν λόγω διαδικασία περιπλέκεται εντονότερα όταν πρόκειται για τη χρηση νερών εμπλουτιμού υποβαθμισμένης ποιότητας. Βασικός στόχος της παρούσας εργασίας είναι η παρουσίαση ενός πρόδρομου εργαλείου πολυ-κριτιριακού Συστήματος Λήψης Αποφάσεων, το οποίο ενσωματώνει σε μια δυναμική πλατφόρμα: τόσο τις τεχνικές του Τ.Ε. όσο και τα γεωγραφικά χαρακτηριστικά που καθορίζουν την αποτελεσματικότητα του έργου. Το προτεινόμενο σύστημα αποτελεί προχωρημένο εργαλείο σύζευξης Συστημάτων Λήψης Αποφάσεων και Γεωγραφικών Πληροφοριών ικανό να αξιολογεί κρίσιμα ζητήματα που αφορούν σε έργα Τ.Ε. –γεωλογικά, υδρογεωλογικά, κλιματολογικά, νομικά, κοινωνικά, οικονομμικά κ.α. – με ιδιαίτερη έμφαση σε συστήματα Επεξεργασίας-Εδάφους- Υδροφόρου. Το συγκεκριμένο εργαλείο πρόκειται να ενσωματωθεί στο λογισμικό ArcGIS, σε περιβάλλον φιλικό προς το χρήστη, όπου η προβολή και επεξεργασία χωρικών δεδομένων μπορεί να πραγματοποιηθεί με τη χρήση Arc tools.Managed Aquifer Recharge is a wide-spread well-established groundwater engineering method which is largely seen as an alternative potential major source for water and this conclusion becomes even more pronounced in semi-arid and/or arid areas, such as the Mediterranean Basin. The process of site selection for the installation of a MAR facility is of paramount importance for the feasibility and effectiveness of the project itself, especially when the facility will include the use of waters of impaired quality as a recharge source. The main objective of this study is to present the developed framework of a multicriteria Decision Support System (DSS) that integrates within a dynamic platform: the main groundwater engineering parameters associated with MAR applications together with the general geographical features which determine the effectiveness of such a project. The proposed system will provide an advanced coupled DSS-GIS tool capable of handling local MAR-related issues -such as hydrogeology, topography, soil, climate etc., and spatially distributed variables -such as societal, economic, administrative, legislative etc., with special reference to Soil-Aquifer- Treatment technologies. The new SAT-selection tool in question is integrated in ArcGIS software -within a user friendly environment- where data can be processed and displayed using Arc tools for spatial analysis

TeV Gamma-Ray Sources from a Survey of the Galactic Plane with Milagro

A survey of Galactic gamma-ray sources at a median energy of ~20 TeV has been performed using the Milagro Gamma Ray Observatory. Eight candidate sources of TeV emission are detected with pre-trials significance $>4.5\sigma$ in the region of Galactic longitude $l\in[30^\circ,220^\circ]$ and latitude $b\in[-10^\circ,10^\circ]$. Four of these sources, including the Crab nebula and the recently published MGRO J2019+37, are observed with significances $>4\sigma$ after accounting for the trials involved in searching the 3800 square degree region. All four of these sources are also coincident with EGRET sources. Two of the lower significance sources are coincident with EGRET sources and one of these sources is Geminga. The other two candidates are in the Cygnus region of the Galaxy. Several of the sources appear to be spatially extended. The fluxes of the sources at 20 TeV range from ~25% of the Crab flux to nearly as bright as the Crab.Comment: Submitted to Ap

Discovery of Localized Regions of Excess 10-TeV Cosmic Rays

An analysis of 7 years of Milagro data performed on a 10-degree angular scale has found two localized regions of excess of unknown origin with greater than 12 sigma significance. Both regions are inconsistent with gamma-ray emission with high confidence. One of the regions has a different energy spectrum than the isotropic cosmic-ray flux at a level of 4.6 sigma, and it is consistent with hard spectrum protons with an exponential cutoff, with the most significant excess at ~10 TeV. Potential causes of these excesses are explored, but no compelling explanations are found.Comment: Submitted to PhysRevLet

Milagro Constraints on Very High Energy Emission from Short Duration Gamma-Ray Bursts

Recent rapid localizations of short, hard gamma-ray bursts (GRBs) by the Swift and HETE satellites have led to the observation of the first afterglows and the measurement of the first redshifts from this type of burst. Detection of >100 GeV counterparts would place powerful constraints on GRB mechanisms. Seventeen short duration (< 5 s) GRBs detected by satellites occurred within the field of view of the Milagro gamma-ray observatory between 2000 January and 2006 December. We have searched the Milagro data for >100 GeV counterparts to these GRBs and find no significant emission correlated with these bursts. Due to the absorption of high-energy gamma rays by the extragalactic background light (EBL), detections are only expected for redshifts less than ~0.5. While most long duration GRBs occur at redshifts higher than 0.5, the opposite is thought to be true of short GRBs. Lack of a detected VHE signal thus allows setting meaningful fluence limits. One GRB in the sample (050509b) has a likely association with a galaxy at a redshift of 0.225, while another (051103) has been tentatively linked to the nearby galaxy M81. Fluence limits are corrected for EBL absorption, either using the known measured redshift, or computing the corresponding absorption for a redshift of 0.1 and 0.5, as well as for the case of z=0.Comment: Accepted for publication in the Astrophysical Journa

Interpreting and acting upon home blood pressure readings: A qualitative study

This article is made available through the Brunel Open Access Publishing Fund. Copyright @ 2013 Vasileiou et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Recent guidelines recognize the importance of home blood pressure monitoring (HBPM) as an adjunct to clinical measurements. We explored how people who have purchased and use a home blood pressure (BP) monitor make sense of, and act upon, readings and how they communicate with their doctor about the practice of home monitoring. Methods: A qualitative study was designed and participants were purposively recruited from several areas in England, UK. Semi-structured in-depth interviews were conducted with 18 users of home BP monitors. The transcribed data were thematically analysed. Results: Interpretation of home BP readings is complex, and is often characterised by uncertainty. People seek to assess value normality using ‘rules of thumb’, and often aim to identify the potential causes of the readings. This is done by drawing on lay models of BP function and by contextualising the readings to personal circumstances. Based on the perceived causes of the problematic readings, actions are initiated, mostly relating to changes in daily routines. Contacting the doctor was more likely when the problematic readings persisted and could not be easily explained, or when participants did not succeed in regulating their BP through their other interventions. Most users had notified their doctor of the practice of home monitoring, but medical involvement varied, with some participants reporting disinterest or reservations by doctors. Conclusions: Involvement from doctors can help people overcome difficulties and resolve uncertainties around the interpretation of home readings, and ensure that the rules of thumb are appropriate. Home monitoring can be used to strengthen the patient-clinician relationship

A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro

Diffuse $\gamma$-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse $\gamma$-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse $\gamma$-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30$^\circ$ and 110$^\circ$ and between 136$^\circ$ and 216$^\circ$ and for Galactic latitudes between -10$^\circ$ and 10$^\circ$ are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region ($l\in[65^\circ,85^\circ]$). For the Cygnus region, the flux is twice the predicted value. This excess can be explained by the presence of active cosmic ray sources accelerating hadrons which interact with the local dense interstellar medium and produce gamma rays through pion decay.Comment: 15 pages, 3 figures, accepted by Ap