GEOTHERMAL EXPLORATION IN THE ALEXANDRIA AREA, THESSALONIKI BASIN (MACEDONIA, NORTHERN GREECE)

Η περιοχή της Αλεξάνδρειας βρίσκεται στη Λεκάνη Θεσσαλονίκης, η οποία έχει πληρωθεί με ιζήματα πάχους άνω των 4 km. To 1980, κατασκευάσθηκε βόρεια της πόλης της Αλεξάνδρειας η γεώτρηση έρευνας υδρογονανθράκων AL-1, βάθους 1705 m, στην οποία καταγράφηκαν οι θερμοκρασίες των 39 και 65oC σε βάθη 700 και 1705 m αντίστοιχα. Μεταξύ 1996 και 2000, ανορύχθηκαν δύο γεωθερμικές ερευνητικές γεωτρήσεις, βάθους 532 και 620 m, οι οποίες διέτρησαν Τεταρτογενή και Πλειοκαινικά ιζήματα και στις οποίες μετρήθηκαν θερμοκρασίες 30.1 και 33.4oC σε βάθη 500 και 611 m αντίστοιχα. Η προκαταρκτική γεωθερμική έρευνα οδήγησε την κατασκευή της πρώτης παραγωγικής γεώτρησης (ΓΝ-1Π). Ανορύχθηκε μέχρι βάθος 805 m διατρύοντας αργίλους, άμμους, τόφφους, μάργες, αργιλο-μάργες, μαργαϊκούς ασβεστόλιθους, χάλικες, ψαμμίτες και κροκαλοπαγή. Η γεώτρηση σωληνώθηκε μέχρι τα 805 m και φίλτρα τοποθετήθηκαν σε διάφορα βάθη κάτω από τα 607 m. Τιμές θερμοκρασίας και ηλεκτρικής αγωγιμότητας 35.1-37.2oC και 5100-8200 μS/cmαντίστοιχα καταγράφηκαν σε βάθη 607-800 m. Η γεώτρηση παρουσιάζει αρτεσιανή ροή με 30-40 m3/h νερών των 34.1oC και παρέχει με άντληση 130 m3/h νερών θερμοκρασίας 35.5oC. Το παραγόμενο γεωθερμικό νερό με ΣΔΑ 2.18 g/l είναι του τύπου Na-Cl και διαφοροποιείται από τα ρηχά νερά. Η θερμική ισχύς της γεώτρησης ΓΝ-1Π υπολογίζεται σε 1.65 MWt.The area of Alexandria is located in the Thessaloniki basin that has been filled with more than 4 km of sediments. In 1980, oil exploration borehole AL-1, 1,705 m deep, was drilled north of the town of Alexandria and the temperatures of 39 and 65oC were recorded at depths of 700 and 1,705 m respectively. During 1996-2000, two geothermal exploration boreholes were drilled at depths of 532 and 620 m penetrating Quaternary and Pliocene sediments and the temperatures of 30.1 and 33.4oC were measured at 500 and 611 m respectively. The preliminary geothermal investigation resulted in the construction of the first production well (GN-1P). It was drilled to a depth of 805 m penetrating clays, sands, tuffs, marls, clayey marls, marly limestones, gravels, sandstones and conglomerates. The borehole was cased down to 805 m and screens were placed at various depths below 607 m. Temperature and electrical conductivity values of 35.1-37.2oC and 5,100-8,200 μS/cm respectively were recorded at depths of 607-800 m. This well discharges 30-40 m3/h waters at 34.1oC with artesian flow and provides 130 m3/h waters at 35.5oC with pumping. The produced geothermal water with TDS of 2.18 g/l belongs to the Na-Cl type differentiated from the shallow waters. The thermal capacity of well GN-1P is calculated to be 1.65 MWt

PRELIMINARY GEOTHERMAL INVESTIGATION IN THE BASIN OF KATERINI (NORTHERN GREECE)

Η παρούσα εργασία περιγράφει τα αποτελέσματα της προκαταρκτικής γεωθερμικής έρευνας που διενεργήθηκε από το ΙΓΜΕ στην λεκάνη της Κατερίνης (Β. Ελλάδα). Οι ερευνητικές εργασίες κατά κύριο λόγο περιελάμβαναν θερμομετρήσεις στην κεφαλή 73 υπαρχουσών υδρογεωτρήσεων, μέτρηση της θερμοκρασίας σε συνάρτηση με το βάθος στο εσωτερικό πέντε (5) γεωτρήσεων και χημικές αναλύσεις 18 δειγμάτων από επιλεγμένες θέσεις. Με βάση τα στοιχεία που προέκυψαν από την κατανομή των θερμοκρασιών, διακρίνονται τρεις επιμέρους περιοχές γεωθερμικού ενδιαφέροντος. Ως σημαντικότερη κρίνεται αυτή του Κάτω Αγίου Ιωάννη (νότια τμήμα της λεκάνης), όπου μετρήθηκαν θερμοκρασίες της τάξης των 27oC σε βάθος 340m. Εν τούτοις, για τη λεπτομερή διερεύνηση των γεωθερμικών συνθηκών στη λεκάνη Κατερίνης, απαιτείται περαιτέρω συστηματική έρευνα και κατασκευή τουλάχιστον μίας ερευνητικής γεωθερμικής γεώτρησης μεγάλου βάθους.This paper describes the results of the preliminary surface geothermal exploration conducted by IGME in the basin of Katerini (Northern Greece). It mainly regards temperature measurements at the wellhead of 73 wells and in the interior of five boreholes, as well as sampling and chemical analyses from 18 selected sites. Based on the collected data, three sub-regions of geothermal interest can be distinguished, the most important of which is the area of Kato Agios Ioannis (to the south of the basin), with temperatures around 27oC at the depth of 340m. Nonetheless, the detailed geothermal investigation of this basin requires further systematic research as well as the drilling of at least one deep geothermal exploration borehole

Geothermal exploration in the Sani-Afytos area of the Kassandra peninsula (Chalkidiki peninsula, Northern Greece)

Η περιοχή Σάνης - Αφύτου της Χερσονήσου Κασσάνδρας (Χα).κιδική) απετέλεσε περιοχή συστηματικής γεωθερμικής έρευνας. Από την αξιολόγηση των δεδομένων βαθιών γεωτρήσεων έρευνας υδρογονανθράκων διαπιστώθηκε το σημαντικό πάχος (μέχρι περίπου 3600 m) των Παλαιογενών, Νεογενών και Τεταρτογενών ιζημάτων που καλύπτουν το μεταμορφωμένο Μεσοζωικό (κυρίως ανθρακικό) υπόβαθρο της περιοχής. Η συστηματική θερμομετρική έρευνα κατέδειξε την παρουσία υπόθερμων; νερών (20-28°C) σε βάθη μέχρι 300 m και την χωρική κατανομή της θερμοκρασίας σε βάθη 150 και 200 m σύμφωνα με τις κύριες τεκτονικές δομές ΒΔ-ΝΑ και ΒΑ-ΝΔ διεύθυνσης της περιοχής. Με την ανόρυξη γεωθερμικών γεωτρήσεων (ερευνητικών και παραγωγής) βάθους 422-583 m εντοπίσθηκαν νερά 31,7-36°C στα Ανω-Μειοκανικά ιζήματα. Η μέση τιμή της γεωθερμικής βαθμίδας υπολογίστηκε σε 3-4°C/100 m. Παραγωγική γεώτρηση βάθους 520 m δίνει νερά 34°C με δυνατότητα παροχής περίπου 50 m3/h. Τα γεωθερμικά νερά είναι Na-HCO} και Na-CI με Σ.Δ.Α. 0,89-2,03 g/l. Με τη βοήθεια χημικών γεωθερμομέτρων εκτιμάται ότι η θερμοκρασία του βαθιού γεωθερμικού ρευστού είναι της τάξης των 80- 100°C. Η παρουσία αέριας φάσης (77% κ.ό. CH4, 21,8% κ.ό. Ν2) διαπιστώθηκε σε μία από τις ερευνητικές γεωτρήσεις. Αποτέλεσμα της γεωθερμικής έρευνας ήταν ο χαρακτηρισμός της περιοχής ως «γεωθερμικό πεδίο Σάνης - Αφύτου» (Φ.Ε.Κ. 1012/τ.Β/19-7-2005) και οι προοπτικές ανάπτυξης με χρήση των γεωθερμικών ρευστών στον τουρισμό και σε άλλες δραστηριότητες.The Sani-Afytos area in the Kassandra Peninsula (Chalkidiki) was the area of systematic geothermal exploration. Based on deep oil borehole data, the Paleogene, Neogene and Quaternary sediments show significant thickness reaching 3600 m and cover the metamorphosed Mesozoic, mainly carbonate, basement. The detailed water temperature investigation proved the presence of sub-thermal waters (20-28°C) at depths up to 300 m and the spatial distribution of the isothermal curves at depths of 150 and 200 m according to the main NW-SE and SE-NW tectonic structures of the area. Through the construction of geothermal exploration and production wells at depths of 422-583 m, thermal waters of 31.7-36°C were detected within the Upper Miocene sediments. The average value of the geothermal gradient was calculated to be 3-4°CI 100 m. One production well of 520 m depth provides waters of 34°C while its potential flow rate is approximately 50 m /h. The geothermal waters were classified in Na-HCOi and Na-CI types of waters with TD. S 0.89-2.03 g/l. With the aid of chemical geothermometers the deep temperature was estimated to be 80-100°C. In one exploration well, the presence of gas phase (77% v/v CH4, 21.8% v/v N2) was detected. The geothermal exploration resulted in the characterization of the area as the "geothermal field of Sani-Afytos" and in the prospective development using the geothermal fluids in the tourism and other activities

Development of a stochastic computational fluid dynamics approach for offshore wind farms

In this paper, a method for stochastic analysis of an offshore wind farm using computational fluid dynamics (CFD) is proposed. An existing offshore wind farm is modelled using a steady-state CFD solver at several deterministic input ranges and an approximation model is trained on the CFD results. The approximation model is then used in a Monte-Carlo analysis to build joint probability distributions for values of interest within the wind farm. The results are compared with real measurements obtained from the existing wind farm to quantify the accuracy of the predictions. It is shown that this method works well for the relatively simple problem considered in this study and has potential to be used in more complex situations where an existing analytical method is either insufficient or unable to make a good prediction

Objective assessment of stored blood quality by deep learning

Stored red blood cells (RBCs) are needed for life-saving blood transfusions, but they undergo continuous degradation. RBC storage lesions are often assessed by microscopic examination or biochemical and biophysical assays, which are complex, time-consuming, and destructive to fragile cells. Here we demonstrate the use of label-free imaging flow cytometry and deep learning to characterize RBC lesions. Using brightfield images, a trained neural network achieved 76.7% agreement with experts in classifying seven clinically relevant RBC morphologies associated with storage lesions, comparable to 82.5% agreement between different experts. Given that human observation and classification may not optimally discern RBC quality, we went further and eliminated subjective human annotation in the training step by training a weakly supervised neural network using only storage duration times. The feature space extracted by this network revealed a chronological progression of morphological changes that better predicted blood quality, as measured by physiological hemolytic assay readouts, than the conventional expert-assessed morphology classification system. With further training and clinical testing across multiple sites, protocols, and instruments, deep learning and label-free imaging flow cytometry might be used to routinely and objectively assess RBC storage lesions. This would automate a complex protocol, minimize laboratory sample handling and preparation, and reduce the impact of procedural errors and discrepancies between facilities and blood donors. The chronology-based machine-learning approach may also improve upon humans’ assessment of morphological changes in other biomedically important progressions, such as differentiation and metastasis

The Healing Process of Intracorporeally and In Situ Devitalized Distal Femur by Microwave in a Dog Model and Its Mechanical Properties In Vitro

Background: Limb-salvage surgery has been well recognized as a standard treatment and alternative to amputation for patients with malignant bone tumors. Various limb-sparing techniques have been developed including tumor prosthesis, allograft, autograft and graft-prosthesis composite. However, each of these methods has short- and long-term disadvantages such as nonunion, mechanical failures and poor limb function. The technique of intracorporeal devitalization of tumor-bearing bone segment in situ by microwave-induced hyperthermia after separating it from surrounding normal tissues with a safe margin is a promising limb-salvage method, which may avoid some shortcomings encountered by the above-mentioned conventional techniques. The purpose of this study is to assess the healing process and revitalization potential of the devitalized bone segment by this method in a dog model. In addition, the immediate effect of microwave on the biomechanical properties of bone tissue was also explored in an in vitro experiment. Methods: We applied the microwave-induced hyperthermia to devitalize the distal femurs of dogs in situ. Using a monopole microwave antenna, we could produce a necrotic bone of nearly 20 mm in length in distal femur. Radiography, bone scintigraphy, microangiography, histology and functional evaluation were performed at 2 weeks and 1, 2, 3, 6, 9 and 12 months postoperatively to assess the healing process. In a biomechanical study, two kinds of bone specimens, 3 and 6 cm in length, were used for compression and three-point bending test respectively immediately after extracorporeall