Drastic method to map groundwater vulnerability to pollution using nitrate measurements in agricultural areas

Η μέθοδος DRASTIC χρησιμοποιείται για την εκτίμηση και τη χαρτογράφηση της εσωτερικής τρωτότητας των υπόγειων νερών από εξωτερικά ρυπαντικά φορτία. Δεδομένου όμως, ότι η μέθοδος εφαρμόζεται σε διαφορετικές περιοχές, χωρίς καμία τροποποίηση, την καθιστά αδύνατη να λάβει υπόψη της τις επιδράσεις του ρυπαντή, ανάλογα με το είδος και τα χαρακτηριστικά του. Συνεπώς, στη μέθοδο DRASTIC θα πρέπει να συνυπολογίζονται τόσο οι ιδιαίτεροι παράμετροι του φυσικού συστήματος του υδροφορέα, όσο και οι ιδιαίτερες συνθήκες κάθε περιοχές (χρήσεις γης). Στα πλαίσια της παρούσας εργασίας, τροποποιώντας τις παραμέτρους της τυπικής μεθόδου DRASTIC και τους αντίστοιχους συντελεστές βαρύτητας, εκτιμήθηκε ο δείκτης τρωτότητας με μεγαλύτερη ακρίβεια. Την περιοχή εφαρμογής της προτεινόμενης μεθοδολογίας αποτελεί η Δελταϊκή περιοχή του προσχωματικού υδροφόρου ορίζοντα του ποταμού Βολιναίου, στην ΒΔ/κή Πελοπόννησο.DRASTIC model has been used to map groundwater vulnerability to pollution in many areas. Since this method is used in different places without any changes, it cannot consider the effects of pollution type and characteristics. Therefore, the method needs to be calibrated and corrected for that aquifer and specific land use. In this research, by correcting the rates of DRASTIC parameters, one can assess the vulnerability potential to pollution more accurately. The new rates were computed using the relationships between DRASTIC INDEX (DI) corresponding to land use and to nitrate concentration in groundwater. The proposed methodology was applied in deltaic region of alluvial aquifer of Volinaios catchment located in the northwestern part of Peloponnesus. In order to determine the quality of the ground waters, either for watering or irrigating purposes, in the study area, a sampling was made. Correlation was used to find the relationship between the index and measured pollution in each point and therefore, to modify the rates. The results showed that the modified DRASTIC is better than the original method for nonpoint source pollution in agricultural areas

Research on kindergarten and primary school students’ magnetic misconceptions and how to plan educational activities

Because magnetism is such an abstract and complicated subject, it can be challenging for children to comprehend at times. Magnetism is a subject that youngsters find to be really exciting. The topic of magnetism is one that children find to be both fascinating and fascinating. There has not been nearly as much research done on how children perceive magnetism as there has been on other natural phenomena. This is even though youngsters consider magnetism to be something that is exciting. Despite the fact that children perceive magnetism to be more attractive than other natural phenomena, this is the case. This particular piece of research is regarded as an important piece of re-search owing to the fact that it has an impact on the way in which learning is experienced. The goal of this study is to analyze the misconceptions that are held by children who are enrolled in elementary school. The research will be conducted with the intention of providing teachers with a theoretical framework upon which they can construct educational activities that are relevant to the requirements of primary school pupils. The ability to construct educational activities that are pertinent to the requirements of elementary school kids will be made possible as a result of this innovation

THE USE OF NEW TECHNOLOGIES AND ROBOTICS (STEM) IN THE TEACHING OF SCIENCES IN PRIMARY EDUCATION: THE CONCEPT OF MAGNETISM: A BIBLIOGRAPHIC REVIEW

The literature on the characteristics of STEM research in primary education (kindergarten and primary school) is limited in Greece. Also, studies on teaching the concept of the magnet with STEM activities in preschool education have been found to be quite insufficient (Büyüktaşkapu et al., 2012). This study presents the theoretical framework related to the clarification of the ICT and STEM concepts, as well as the effectiveness of their integration in Primary Education both in Greece and abroad, in the teaching of Natural Sciences and specifically in what concerns the concept of magnetism. In order to investigate the effectiveness of ICT and STEM, the existing perceptions of K12 children on which the planning and implementation of the teaching interventions were based are listed.  Article visualizations

Random local strain effects in homovalent-substituted relaxor ferroelectrics: a first-principles study of BaTi0.74Zr0.26O3

We present first-principles supercell calculations on BaTi0.74Zr0.26O3, a prototype material for relaxors with a homovalent substitution. From a statistical analysis of relaxed structures, we give evidence for four types of Ti-atom polar displacements: along the , , or directions of the cubic unit cell, or almost cancelled. The type of a Ti displacement is entirely determined by the Ti/Zr distribution in the adjacent unit cells. The underlying mechanism involves local strain effects that ensue from the difference in size between the Ti4+ and Zr4+ cations. These results shed light on the structural mechanisms that lead to disordered Ti displacements in BaTi(1-x)Zr(x)O3 relaxors, and probably in other BaTiO3-based relaxors with homovalent substitution.Comment: 5 pages, 4 figure

First principles based atomistic modeling of phase stability in PMN-xPT

We have performed molecular dynamics simulations using a shell model potential developed by fitting first principles results to describe the behavior of the relaxor-ferroelectric (1-x)PbMg1/3Nb2/3O3-xPbTiO3 (PMN-xPT) as function of concentration and temperature, using site occupancies within the random site model. In our simulations, PMN is cubic at all temperatures and behaves as a polar glass. As a small amount of Ti is added, a weak polar state develops, but structural disorder dominates, and the symmetry is rhombohedral. As more Ti is added the ground state is clearly polar and the system is ferroelectric, but with easy rotation of the polarization direction. In the high Ti content region, the solid solution adopts ferroelectric behavior similar to PT, with tetragonal symmetry. The ground state sequence with increasing Ti content is R-MB-O-MC-T. The high temperature phase is cubic at all compositions. Our simulations give the slope of the morphotropic phase boundaries, crucial for high temperature applications. We find that the phase diagram PMN-xPT can be understood within the random site model.Comment: 27 pages, 9 figure

A bird's eye view: using geographic analysis to evaluate the representativeness of corvid indicators for West Nile virus surveillance

BACKGROUND: The objective of this evaluation was to determine whether reports of dead corvid sightings and submissions of dead corvids for West Nile virus testing were representative of true corvid mortality in British Columbia in 2004, a year with no West Nile virus activity, in order to ensure the system was accurately describing corvid mortality rather than reflecting regional differences in surveillance methods. RESULTS: Local Health Areas reported 0–159 (median = 3) dead corvid sightings and 0–209 (median = 5) submissions for West Nile virus testing. The expected numbers of dead corvid sightings and submissions for testing from each Local Health Area were 0–232 (median = 3) and 0–258 (median = 4), respectively. Twelve Local Health Areas reported significantly fewer sightings than expected; 21 reported significantly more. Eleven Local Health Areas submitted significantly fewer corvids than expected; 26 submitted significantly more. CONCLUSION: Some Local Health Areas were over-represented and others under-represented in terms of corvid West Nile virus surveillance indicators. Recommendations were made to improve the representativeness of corvid surveillance data. Geographic analysis can be used to evaluate the representativeness of surveillance systems and result in improvements to surveillance

Carbon dioxide adsorption and interaction with formation fluids of Jordanian unconventional reservoirs

Shales are mostly unexploited energy resources. However, the extraction and production of their hydrocarbons require innovative methods. Applications involving carbon dioxide in shales could combine its potential use in oil recovery with its storage in view of its impact on global climate. The success of these approaches highly depends on various mechanisms taking place in the rock pores simultaneously. In this work, properties governing these mechanisms are presented at technically relevant conditions. The pendant and sessile drop methods are utilized to measure interfacial tension and wettability, respectively. The gravimetric method is used to quantify CO2 adsorption capacity of shale and gas adsorption kinetics is evaluated to determine diffusion coefficients. It is found that interfacial properties are strongly affected by the operating pressure. The oil-CO2 interfacial tension shows a decrease from approx. 21 mN/m at 0.1 MPa to around 3 mN/m at 20 MPa. A similar trend is observed in brine-CO2 systems. The diffusion coefficient is observed to slightly increase with pressure at supercritical conditions. Finally, the contact angle is found to be directly related to the gas adsorption at the rock surface: Up to 3.8 wt% of CO2 is adsorbed on the shale surface at 20 MPa and 60 °C where a maximum in contact angle is also found. To the best of the author’s knowledge, the affinity of calcite-rich surfaces toward CO2 adsorption is linked experimentally to the wetting behavior for the first time. The results are discussed in terms of CO2 storage scenarios occurring optimally at 20 MPa

Fluoroscopy-guided procedures in cardiology: is patient exposure being reduced over time?

The number of fluoroscopy-guided procedures in cardiology is increasing over time and it is appropriate to wonder whether technological progress or change of techniques is influencing patient exposure. The aim of this study is to examine whether patient dose has been decreasing over the years. Patient dose data of more than 7700 procedures were collected from two cardiology centres. A steady increase in the patient dose over the years was observed in both the centres for the two cardiological procedures included in this study. Significant increase in dose was also observed after the installation of a flat-panel detector. The increasing use of radial access may lead to an increase in the patient exposure. The monitoring of dose data over time showed a considerable increase in the patient exposure over time. Actions have to be taken towards dose reduction in both the centre