Effects of turbidity on the equatorial circulation using numerical simulations

Η θολερότητα επηρεάζει άμεσα τις φυσικές ιδιότητες του παγκόσμιου ωκεανού μέσω της απορρόφησης της ηλιακής ακτινοβολίας από τα ανώτερα στρώματα. Η παρούσα εργασία επικεντρώνεται στη μελέτη αυτών των επιδράσεων, κυρίως στον Ισημερινό, διεξάγοντας πειράματα ευαισθησίας με τη χρήση ωκεανογραφικού συζευγμένο με βιοχημικό αριθμητικού μοντέλου (NEMO GCM-PISCES). Διεξάγονται τέσσερα πειράματα, στα οποία διαφορετικές παραμετροποιήσεις για την διείσδυση της ηλιακής ακτινοβολίας αντιστοιχούν σε διαφορετικές συνθήκες θολερότητας. Τα πρώτα δύο πειράματα χρησιμοποιούν συνολικά σταθερές τιμές για το βάθος διείσδυσης της ηλιακής ακτινοβολίας ώστε να αντιπροσωπεύουν καθαρά και θολά νερά αντίστοιχα. Στο τρίτο και στο τέταρτο πείραμα το βάθος διείσδυσης εξαρτάται από τη συγκέντρωση της επιφανειακής χλωροφύλλης, όπου το τρίτο πείραμα χρησιμοποιεί μετρήσεις χλωροφύλλης από δορυφόρο και το τέταρτο πείραμα χρησιμοποιεί χλωροφύλλη που παράγεται από το βιοχημικό μοντέλο. Συγκρίνοντας τα πειράματα παρατηρήθηκε ότι η αυξανόμενη θολερότητα προκαλέι αύξηση του SST παντού, εκτός του Ισημερινού, όπου αυξάνεται η ανάβλυση των υδάτων, φέρνοντας ψυχρότερα SSTs στην επιφάνεια. Τα ψυχρότερα SSTs του Ισημερινού μειώνουν την επιφανειακή τάση του ανέμου τοπικά στον Ισημερινό και ενώ αυτό τείνει να μειώνει την απόκλιση και την ανάβλυση, τα αποτελέσματα δείχνουν ότι είναι η αυξημένη, εκτός του Ισημερινού τάση ανέμου που οδηγεί στην αύξηση της ανάβλυσης και της μείωσης τοτυ SST.Turbidity affects directly the physical properties of the global ocean through the absorption of solar radiation by the upper layers. The present thesis focuses on studying these effects, mainly on the equatorial region, by conducting sensitivity experiments with the use of an ocean circulation coupled with a biochemical numerical model (NEMO GCM-PISCES). Four experiments are performed, in which different parameterizations for the penetrative solar radiation correspond to different turbidity regimes. The first two experiments use globally constant values for the solar radiation penetration depth to represent clear and turbid waters respectively. In the third and fourth experiments the penetration depth depends on the concentration of the surface chlorophyll, where the third experiment uses remote sensing chlorophyll measurements and the fourth experiment uses chlorophyll produced by the biochemical model. Comparing the experiments showed that increasing turbidity produces SST increase everywhere but in the equatorial regions, where the open ocean upwelling is increased, bringing colder SSTs to the surface. Colder equatorial SSTs decrease the surface wind stress locally on the equator and while this tends to decrease divergence and upwelling, the results show that it is the increased off-equatorial wind stress that drives the increase in the upwelling and equatorial SST cooling

Robotic Orthotopic Neobladder: The Two Chimney Technique

Bladder substitution following radical cystectomy for urothelial cancer (transitional cell carcinoma) has become increasingly common and in many centers has evolved to become the standard method of urinary diversion. Orthotopic neobladder has been a commonly used option for urinary diversion since the 1980s. Advantages of this type of diversion are the ability to avoid an ostomy, voiding function similar to the native bladder, and improved cosmesis. Robotic intracorporeal neobladder creation has demonstrated similar outcomes to open technique and represents a promising minimally invasive diversion for the future. The Studer pouch is widely used nowadays, yet there are still some drawbacks. Therefore, we designed a technique that would offer an orthotopic ureteroileal anastomosis by using a two chimney modification. This modification is simple to handle, safe and free of ureteric stricture or reflux. With low stricture rates, this modified procedure of ureterointestinal anastomosis, is worthy of further promotion

Bioenergy and fertilizer production from poultry manure. Design, exergy and environmental analysis. Cace study of the Municipality of Megara

151 σ.Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Περιβάλλον και Ανάπτυξη”The use of energy is currently the focus of most human activities, while many of the environmental problems of modern societies refer as a benchmark of technology production and use. The energy resources are an example of exhaustion of natural resources, whose excessive use brings about a dramatic impact on both cost of living and life itself on earth. This thesis aims to approach ways of utilization of poultry waste as an energy resource, from the perspective of Renewable Energy Sources (RES). Given the acute problem that occurs in both national and local level in the management of agricultural waste, particularly livestock, the examination in the light of a modern and detailed methodology may yield new data and provide useful guidelines and principles in addressing the issue. The goal then is a general presentation of the theoretical framework for poultry waste, existing methods of management and evaluation of the present situation in Greece. The case of the Municipality of Megara is chosen in order to identify the problem in real conditions. The area is a representative example of a municipality with a large capacity of poultry and severe problem in waste management. At the introduction, Chapter 1, a general approach to the problem of poultry waste in relation with the anthropocentric environment is attempted. Then, the exposition of problems around poultry waste is essential. Thus, in Chapter 2 the basic concepts of poultry waste are defined, such as composition, production volume of waste, pollution load, and environmental costs and impacts. In Chapter 3 a detailed description of modern technologies and methods with worldwide application as well as reference to the parameters and factors affecting them is accomplice. Furthermore an overall assessment and comparison of these methods is carried out in relation to poultry waste. In Chapter 4 a detailed analysis of the final products of anaerobic digestion, as a method of treatment of poultry waste, is made, with emphasis on the construction of similar plant, plant parts, economic analysis, and ability of the method to produce biogas and compost. Moreover, in Chapter 5 the problem in the Municipality of Megara is delineated. The current management waste practice is described and an analysis of parameters that must be taken under consideration in waste practice adjustment is accomplice. Such parameters have reference to population data, region‘s geography / geology, climate, land use and the use of RES. Chapter 6 is the analysis of method chosen for poultry waste utilization related to Municipality of Megara needs. Additionally, implementation and effectuation of a poultry waste management plan in accordance with the data obtained for the study area is attempted. Economic analysis, environmental impact, and exergy analysis consider integral parts of such an analysis. In Chapter 7 the main conclusions drawn for both the problem of the management of poultry waste, and the application of alternative forms of management which are proposed for the Municipality of Megara are mentioned.Παναγιώτης Ι. Ανδριόπουλο

Endocarditis as a Late Onset Complication of Brucellosis

Brucella endocarditis (BE) is a rare but life threatening complication of brucellosis. We present a case report of a patient with relapsing brucellosis complicated with aortic valve endocarditis. The patient underwent valve replacement and required prolonged antibiotic treatment because of rupture of the noncoronary leaflet and development of congestive heart failure. Since the onset of endocarditis in patients with brucellosis is not known, proper follow-up is required in order to identify any late onset complications, especially in endemic areas

Brucella Endocarditis as a Late Onset Complication of Brucellosis

Brucella endocarditis (BE) is a rare but life threatening complication of brucellosis. We present a case report of a patient with relapsing brucellosis complicated with aortic valve endocarditis. The patient underwent valve replacement and required prolonged antibiotic treatment because of rupture of the noncoronary leaflet and development of congestive heart failure. Since the onset of endocarditis in patients with brucellosis is not known, proper follow-up is required in order to identify any late onset complications, especially in endemic areas

Brucella Seroprevalence in a High-Risk Population in Greece: A Cross-Sectional Study

Introduction. Brucellosis is a zoonosis with high occupational risk. However, seroprevalence of Brucella antibodies among occupational groups is not known, since studies in endemic countries are rare. Methods. A cross-sectional seroprevalence study was conducted among livestock farmers in an endemic region in Greece. A low-risk group of individuals that just moved in the region was used as controls. Rose Bengal, Wright standard tube agglutination (STA) tests, and specific IgG and IgM antibodies using ELISA were evaluated; differences and odds ratios were calculated. Results were compared with studies from other endemic regions. Results. 100 livestock farmers and family members and 34 first-year students were enrolled. Rose Bengal results were 18% positive versus 0% (p=0.007); Wright STAs for Brucella melitensis were 8% versus 2.9% (p=0.448) and for Brucella abortus they were 2% versus 2.9% (p=0.588). ELISA IgG was positive in 8% of farmers versus 2.9% of students (p=0.448). Parallel testing with Rose Bengal and ELISA IgG was positive in 3% versus 0% (p=0.571). No significant odds ratios were calculated for Wright STAs and ELISA IgG. Conclusions. Healthy livestock farmers may present with positive Rose Bengal test but this translates to true seroprevalence in only a small proportion. Livestock farmers have no significant seroprevalence that may obscure diagnosis of acute brucellosis in clinical settings