Κοσμολογικό Μοντέλο Bianchi τύπου V σε συνδυασμό με Άμαζο Βαθμωτό Πεδίο

Σε αυτή την εργασία θα ερευνήσουμε τις συμμετρίες στο χωροχρόνο και τους τρόπους με τους οποίους μπορούμε να τις εντοπίσουμε. Επίσης, θα παρατεθούν παραδείγματα για άμαζα βαθμωτά πεδία. Με τη βοήθεια των παραγώγων Lie και της Lie άλγεβρας, η θεωρία της οποίας αναλύεται στο πρώτο κεφάλαιο, θα μελετήσουμε τις συμμετρίες και μέσω της κλασικής μηχανικής θα προσπαθήσουμε να εντοπίσουμε σημεία μοναδικότητας και να βρούμε τα πεδία Killing, τα οποία μας δίνουν τη συμμετρία στο χώρο. Στο τελευταίο κεφάλαιο επικεντρωνόμαστε την μελέτη ενός συγκεκριμένου κοσμολογικού μοντέλου, του Bianchi τύπου V συνδεδεμένου με άμαζο βαθμωτό πεδίο.In this paper we will investigate the spacetime symmetries and the ways that we can use to find them. Furthermore, examples will be presented regarding massless scalar fields. With the help provided by Lie derivatives and Lie algebra, the theory of which is analyzed in the first chapter, we will study the symmetries and through classical mechanics we will try to identify the singularities and find the Killing fields, which give symmetry in space. In the final chapter we focus on the study of a specific cosmological model, Bianchi type V, coupled to a massless scalar field

Στρωματογραφικές και πετρελαϊκές παρατηρήσεις στους Ιουρασικούς-Κάτω Κρητιδικούς σχηματισμούς της Προαπούλιας ζώνης στην περιοχή Αθανίου (Λευκάδα)

Η εργασία ασχολείται με την διερεύνηση του Ιουρασικού αργιλοπυριτικού σχηματισμού ως μητρικού πετρώματος πετρελαίου, και την στρωματογραφική του πλαισίωση μέσω της εργαστηριακής μελέτης συλλεχθέντων δειγμάτων στην περιοχή η οποία βρίσκεται δυτικά του χωριού Αθάνιου, στο νοτιοδυτικό τμήμα της ακτογραμμής της Λευκάδας, δυτικά της επώθησης της Ιόνιας πάνω στην Προαπούλια ζώνη. Η περιοχή μελέτης αποτελεί το μόνο χερσαίο χώρο στον οποίο εμφανίζονται πετρώματα του Ιουρασικού της Προαπούλιας ζώνης. Γεωχημική μελέτη δειγμάτων γεωτρήσεων που πραγματοποίησε η ΔΕΠ- ΕΚΥ στους Παξούς έδειξε ότι ο αργιλοπυριτικός σχηματισμός είναι πλούσιος σε οργανικό υλικό και αντιστοιχεί σε μητρικό πέτρωμα υδρογονανθράκων. Οι δειγματοληψίες υπαίθρου περιέλαβαν τόσο στον αργιλοπυριτικό σχηματισμό όσο και τον υπερκείμενο και το υποκείμενό του. Στην συνέχεια έγινε μελέτη γεωλογικών τομών που περιείχαν τον υπό μελέτη σχηματισμό έτσι ώστε να αναγνωριστεί η στρωματογραφική του θέση και τα ιδιαίτερα στρωματογραφικά και ιζηματολογικά χαρακτηριστικά των εμπλεκόμενων σχηματισμών. Τα δείγματα πετρωμάτων αριθμήθηκαν και τοποθετήθηκαν στο αντίστοιχο ύψος στη στρωματογραφική στήλη. Ακολούθησε γενικότερη μελέτη της στρωματογραφίας της νήσου από την βιβλιογραφία και τα αποτελέσματα της παρούσας μελέτης, καθώς και η ένταξή τους στο ευρύτερο γεωλογικό πλαίσιο. Από την παραπάνω μελέτη προέκυψε ότι τα δείγματα ήταν σε μεγάλο βαθμό δολομιτιωμένα και η πρωτογενής ιζηματογενής δομή ήταν δύσκολο να διευκρινιστεί τα δε μικροαπολιθώματα δεν προσδιορίζονταν λόγω της ανακρυστάλλωσης τους. Παρ’ όλα αυτά εντοπίστηκε στον αργιλικό σχηματισμό ένα απολίθωμα αμμωνίτη του γένους Perisphectites, το οποίο δείχνει πελαγικό περιβάλλον απόθεσης και χρονολογεί τον εν λόγω σχηματισμό στο Ανώτερο Ιουρασικό. II Περαιτέρω εργαστηριακές μελέτες, που δεν μπορούσαν να γίνουν στα πλαίσια μιας διπλωματικής εργασίας, περιλαμβάνουν τη χημική ανάλυση (πυρόλυση) των φαινομενικά πιο πλούσιων σε οργανικό υλικό οριζόντων του σχηματισμού με στόχο την ποσοτικοποίηση των πετρελαϊκών παραμέτρων.The work deals with the exploration of Jurassic aluminosilicate formation as a parent oil bed, and its stratigraphic framework through the laboratory study collected samples in the area to the west Athanasios village, in the southwestern part of the coastline of Lefkada, to the west of the Ionian on the Prevalouli belt. OR study area is the only land area to which the rocks of Jurassic of the Prophetic Belt appear. Geochemical study of drilling samples carried out by ADEP- EKY in Paxos showed that the aluminosilicate formation is rich in organic material and corresponding to parent rock hydrocarbons. Rural sampling included both aluminosilicate formation as well as its supernatant and its subject. In a study of the geological sections containing the study was carried out formation so as to identify its stratigraphic position and particular stratigraphic and sedimentary characteristics of the involved formations. Rock samples were numbered and placed at the corresponding height in the stratigraphic column. A general study of the island 's stratigraphy followed the bibliography and the results of this study, as well and their integration into the wider geological context. The above study showed that the samples were large grade primitive and the primary sedimentary structure was difficult to pinpoint and the small fossils were not identified due to their recrystallization. However, it was detected in aluminous formation of a genus ammonite fossil Perisphectites, showing pelagic deposition environment and dates to that formation in Upper Jurassic. II Further laboratory studies, which could not be done in within a diplomatic work, include chemical analysis (pyrolysis) of the seemingly richer organic matter horizons of the formation with the aim of quantification of petroleum products parameters

Diffuse anorectal melanoma; review of the current diagnostic and treatment aspects based on a case report

Primary anorectal melanoma is a rare and aggressive disease. Patients commonly complain for changes in bowel habits and rectal bleeding, and proctoscopically they mostly appear as non pigmented or lightly pigmented polypoid lesions. Such a lesion should always raise a high index of suspicion in any gastroenterologist or surgeon to prompt surgery, since early radical excision is the only treatment option

Spontaneous regression of a true splenic cyst: a case report and review of the literature

Splenic cysts are rare clinical findings, detected due to derivative symptoms or as a random discovery in abdominal imaging. Although there still remains controversy as to their optimal treatment, bigger secondary cysts should be treated surgically. However, spontaneous regression may be observed in cysts with a diameter smaller than 4 cm. In these cases, expectant treatment is preferable. We report, herein, a single case of a splenic cyst in an adult woman, who reported minor symptoms despite the size of the lesion and who demonstrated a possible almost total regression of the cyst within a ten-year period, accompanying with review of the most recent literature

Duplicated gallbladder: surgical application and review of the literature

Duplicated gallbladder is a rare congenital anomaly, usually asymptomatic and occurring as incidental radiographic or surgical finding during upper abdomen, liver and extrahepatic biliary tract surgery. We report on a case of two separate gallbladders, one main and one accessory, each one with its own cystic duct. The main cystic duct drained into the common bile duct while the accessory bile duct extruded into the left side of common bile duct just inferior to the main cystic duct termination. Imaging advances such as computerized tomography, intraoperative endoscopic retrograde cholangiopancreatography and magnetic resonance cholangiopancreatography may aid in the establishment of accurate diagnosis. The anomaly is of great importance because the surgeon may miss the main or the accessory gallbladder and the patient may need to be re-operated in case of cholelithiasis

Influence of Temperature and Humidity on the Efficacy of Spinosad Against Four Stored-Grain Beetle Species

In the present work, we examined the insecticidal effect of spinosad, against adults of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) on wheat and the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae) on maize. The dose rates used were 0.01, 0.1, 0.5 and 1 ppm. The bioassays were carried out at three temperatures, 20, 25 and 30°C and two relative humidity levels, 55 and 75%. Mortality of R. dominica and S. oryzae was high even at 0.01 ppm of spinosad, reaching 100% at 55% relative humidity and 30° after 21 days of exposure. Generally, mortality of R. dominica, increased with temperature while for S. oryzae mortality increased with temperature and with the decrease of relative humidity. Moreover, for S. oryzae, mortality was low at 20°C. In the case of T. confusum, mortality was low at doses between 0.01 and 0.5 ppm even after 21 days of exposure. At 1 ppm, mortality exceeded 90% only at 30°C and only after 21 days of exposure. Mortality of P. truncatus was low on maize treated with 0.01 ppm, but increasing the dose to 0.1 ppm resulted in > 87% mortality after 14 days of exposure. In several combinations tested, spinosad efficacy notably varied according to the temperature and humidity regimes. Of the species tested, R. dominica and P. truncatus were very susceptible to spinosad, followed by S. oryzae, while T. confusum was the least susceptible

Surgical treatment of giant mesenteric fibromatosis presenting as a gastrointestinal stromal tumor: a case report

<p>Abstract</p> <p>Introduction</p> <p>Intra-abdominal fibromatosis, usually located at the mesenteric level, is a locally invasive tumor of fibrous origin, with no ability to metastasize, but a tendency to recur. Certain non-typical cases of intra-abdominal fibromatosis with involvement of the bowel wall can be misdiagnosed because of their different biological behavior.</p> <p>Case presentation</p> <p>We describe the case of a 64-year-old Caucasian man presenting with mesenteric fibromatosis and involvement of the bowel wall, who was treated surgically. The macroscopic and microscopic appearance of the lesion mimicked a gastrointestinal stromal tumor, a tumor with potential malignant behavior.</p> <p>Conclusion</p> <p>It is essential to make an early and correct diagnosis in such equivocal cases, so that the appropriate treatment can be chosen and suitable patients admitted to clinical trials if appropriate. New and reliable criteria for discriminating between intra-abdominal fibromatosis and gastrointestinal stromal tumor should be proposed and established because novel sophisticated therapeutic strategies have been introduced in the international literature.</p

High origin of a testicular artery: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Although variations in the origin of the testicular artery are not uncommon, few reports about a high origin from the abdominal aorta exist in the literature. We discuss the case of a high origin of the testicular artery, its embryology, classification systems, and its clinical significance.</p> <p>Case presentation</p> <p>We report a very rare case of high origin of the left testicular artery in a 68-year-old Caucasian male cadaver. The artery originated from the anterolateral aspect of the abdominal aorta, 2 cm cranially to the ipsilateral renal artery. Approximately 1 cm after its origin, it branched off into the inferior suprarenal artery. During its course, the artery crossed anterior to the left renal artery.</p> <p>Conclusions</p> <p>A knowledge of the variant origin of the testicular artery is important during renal and testicular surgery. The origin and course must be carefully identified in order to preserve normal blood circulation and prevent testicular atrophy. A reduction in gonadal blood flow may lead to varicocele under circumstances. A knowledge of this variant anatomy may be of interest to radiologists and helpful in avoiding diagnostic errors.</p