1,156 research outputs found
Evidence for Seismogenic Hydrogen Gas, a Potential Microbial Energy Source on Earth and Mars
M thanks the STFC for a PhD studentship and the NASA Astrobiology Institute for additional funding (NNAI13AA90A; Foundations of Complex Life, Evolution, Preservation and Detection on Earth and Beyond). Alison Wright, Roger Gibson and Edward Lynch are thanked for contributing samples. We thank three anonymous reviewers for their insightful comments.Peer reviewedPostprin
Microscale capillary wave turbulence excited by high frequency vibration
Low frequency (O(10 Hz−10 kHz)) vibration excitation of capillary waves has been extensively studied for nearly two centuries. Such waves appear at the excitation frequency or at rational multiples of the excitation frequency through nonlinear coupling as a result of the finite displacement of the wave, most often at one-half the excitation frequency in so-called Faraday waves and twice this frequency in superharmonic waves. Less understood, however, are the dynamics of capillary waves driven by high-frequency vibration (>O(100 kHz)) and small interface length scales, an arrangement ideal for a broad variety of applications, from nebulizers for pulmonary drug delivery to complex nanoparticle synthesis
A shrinking core model for steam hydration of CaO-based sorbents cycled for CO2 capture
Calcium looping is a developing CO2 capture technology. It is based on the reversible carbonation of CaO
sorbent, which becomes less reactive upon cycling. One method of increasing the reactivity of unreactive
sorbent is by hydration in the calcined (CaO) form. Here, sorbent has been subjected to repeated cycles of
carbonation and calcination within a small fluidised bed reactor. Cycle numbers of 0 (i.e., one calcination),
2, 6 and 13 have been studied to generate sorbents that have been deactivated to different extents.
Subsequently, the sorbent generated was subjected to steam hydration tests within a thermogravimetric
analyser, using hydration temperatures of 473, 573 and 673 K. Sorbents that had been cycled less prior to
hydration hydrated rapidly. However, the more cycled sorbents exhibited behaviour where the hydration
conversion tended towards an asymptotic value, which is likely to be associated with pore blockage. This
asymptotic value tended to be lower at higher hydration temperatures; however, the maximum rate of
hydration was found to increase with increasing hydration temperature. A shrinking core model has been
developed and applied to the data. It fits data from experiments that did not exhibit extensive pore blockage
well, but fits data from experiments that exhibited pore blockage less well
Diversity and Ranking of ENSO Impacts along the Eastern Seaboard of Subtropical Southern Africa
El Nino–Southern Oscillation (ENSO) is the dominant mode of interannual climate variability over southern Africa during the summer half of the year. It is widely accepted that El Nino (La Nina) core summers (December–February) are typically warmer and drier (cooler and wetter) than average over the region. Although it is recognized that the ENSO impacts are nonlinear and not all events result in the expected impact, little or no work has been carried out to systematically explore the diversity and ranking of these impacts. Here, parameter-space bubble plots involving various rainfall and temperature metrics are used to study how such impacts vary over the eastern seaboard of subtropical southern Africa to determine the ENSO events with the strongest impacts, and to identify the most anomalous ENSO cases. Comparison of neutral summers experiencing the strongest droughts/floods with ENSO impacts is also performed. These metrics are designed to be applicable to the interests of farmers and other user groups. It is found that 1987/1988 (2017/2018) was the most unusual El Nino (La Nina) and neutral 1981/1982 had a severe drought, worse than occurs during most El Ninos. These unusual cases are explained in terms of regional circulation and SST anomalies. Implications of the results for seasonal forecasting and for farmers are discussed
Paradigm shift in determining Neoproterozoic atmospheric oxygen
ACKNOWLEDGMENTS We thank the Geological Survey of Australia for permission to sample the Empress 1A and Lancer 1 cores, the Natural Sciences and Engineering Research Council of Canada for financial support (grant #7961–15) of U. Brand, and the National Natural Science Foundation of China for support of F. Meng and P. Ni (grants 41473039 and 4151101015). We thank M. Lozon (Brock University) for drafting and constructing the figures. We thank the editor, Brendan Murphy, as well as three reviewers (Steve Kesler, Erik Sperling, and an anonymous reviewer), for improving the manuscript into its final form.Peer reviewedPublisher PD
Ιστορική και πολεοδομική εξέλιξη της πόλης του Βερολίνου - Συγκριτική μελέτη αναβάθμισης υποβαθμισμένων περιοχών σε Αθήνα και Βερολίνο
130 σ.Αντικείμενο της διπλωματικής εργασίας είναι η ιστορική αναδρομή και πολεοδομική εξέλιξη της πόλης του Βερολίνου από την ίδρυσή της μέχρι σήμερα, όπως και η σύγκριση δύο πρώην υποβαθμισμένων περιοχών που αναβαθμίστηκαν τις τελευταίες δύο δεκαετίες, σε Βερολίνο και Αθήνα αντίστοιχα. Η περιγραφή αυτή έχει ως σκοπό την παρουσίαση της σπουδαιότητας και του ρόλου του Βερολίνου δια μέσου των αιώνων, την επισήμανση των πολιτικών, νομοθετικών και πολεοδομικών γεγονότων και εξελίξεων που έπαιξαν σημαντικό ρόλο στην πορεία του, καθώς και τον εντοπισμό ομοιοτήτων και διαφορών από την ανάλυση της σύγκρισης των δύο περιοχών μελέτης.
Η παρούσα διπλωματική εργασία αποτελείται από έξι κεφάλαια.
Στο Κεφάλαιο 1 δίνονται γενικές πληροφορίες για το Βερολίνο, περιγράφοντας τη γεωγραφική θέση και έκταση, το κλίμα, τον πληθυσμό, τα δημογραφικά στοιχεία και την διοικητική διαίρεση της πόλης.
Στο Κεφάλαιο 2 παρουσιάζεται η ιστορική αναδρομή του Βερολίνου από την ίδρυση του το 1237 μέχρι και σήμερα, επισημαίνοντας τα σημαντικότερα ιστορικά γεγονότα.
Στο Κεφάλαιο 3 αναλύονται πολεοδομικά σχέδια (Σχέδια Χρήσης Γης), που έπαιξαν σημαντικό ρόλο στην εξέλιξη του Βερολίνου, ως προς τον σκοπό, το περιεχόμενο και τις επιπτώσεις τους, περιγράφοντας παράλληλα την πολιτική, νομοθετική και πολεοδομική εξέλιξη της πόλης.
Στο Κεφάλαιο 4 εξετάζεται η αναβάθμιση της περιοχή μελέτης Warschauer Straße του Βερολίνου.
Στο Κεφάλαιο 5 εξετάζεται η αναβάθμιση της περιοχής μελέτης του Γκαζιού της Αθήνας.
Στο Κεφάλαιο 6 περιλαμβάνονται τα συμπεράσματα και τα αποτελέσματα της σύγκρισης των δύο περιοχών μελέτης.Subject of the thesis is the historical overview and urban development of the city of Berlin from its foundation until today, as well as the comparison of two formerly degraded areas that have been upgraded over the past two decades, in Berlin and Athens respectively. This description is intended to show the importance and role of Berlin through the ages, highlight political, legislative and planning events and developments that played an important role in its course, and identify similarities and differences from the comparison analysis of the two study areas.
This thesis consists of six chapters.
Chapter 1 contains general information about Berlin, describing the geographical location and area, climate, population, demographics and administrative division of the city.
Chapter 2 presents the historical overview of Berlin from its founding in 1237 until today, highlighting the most important historical events.
In Chapter 3 we continue with the analysis of the aim, the contents, and the impact of urban plans (Land Use Plans), which played an important role in the evolution of Berlin, while describing the political, legislative and urban development of the city.
Chapter 4 examines the upgrade of the study area Warschauer Straße, Berlin.
Chapter 5 examines the upgrade of the study area of Gazi, Athens.
Chapter 6 gives the conclusions and results of the comparison of the two study areas.Βασίλειος Σ. Βλάχο
- …