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ABSTRACT It has long been recognized that the forces that lead to the agglomeration of economic activity and to aggregate growth are similar. Unfortunately, few formal frameworks have been advanced to explore this link. We critically discuss the literature and present a simple framework that can circumvent some of the main obstacles we identify. We discuss the main characteristics of an equilibrium allocation in this dynamic spatial framework, present a numerical example to illustrate the forces at work, and provide some supporting empirical evidence. 相似文献
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Stefan Höjelid 《European Legacy》2010,15(4):467-482
How are we to understand and analyse the constitutional tension in Turkey between the judiciary and the political sphere? In this article the issue is mirrored in the political crisis which started in April 2007 with the nomination of Abdullah Gül as presidential candidate by the moderate Islamist Justice and Development Party (AKP). The more detailed empirical background consists primarily of the dress code problematics including the matter of party closure. Theoretically, the “hegemonic preservation” thesis elaborated by Ran Hirschl turned out to be a useful instrument when it comes to explaining this political crisis as well as the origin of the so-called new constitutionalism. This is illustrated by the judicial activism in the headscarf affair as well as by the eagerness of the Republican People's Party (CHP), as the political representative of the secular establishment, to play the ‘Atatürk card’ and to submit the protection of their interest to an independent judiciary and not to the uncertainties of the mechanisms of majoritarian democracy. However, with regard to the current Turkish case my analysis also shows that Hirschl's thesis is too static and should be complemented with a more dynamic perspective of constitutional politics as a repeated game. One example of this is that even if the Turkish Constitutional Court (TCC) had declared the constitutional amendment on the headscarf invalid and voted for economic sanctions against the AKP, it did not close the party down. 相似文献
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M. G. Blöcher G. Zimmermann I. Moeck W. Brandt A. Hassanzadegan F. Magri 《Geofluids》2010,10(3):406-421
Understanding hydrothermal processes during production is critical to optimal geothermal reservoir management and sustainable utilization. This study addresses the hydrothermal (HT) processes in a geothermal research doublet consisting of the injection well E GrSk3/90 and production well Gt GrSk4/05 at the deep geothermal reservoir of Groß Schönebeck (north of Berlin, Germany) during geothermal power production. The reservoir is located between ?4050 to ?4250 m depth in the Lower Permian of the Northeast German Basin. Operational activities such as hydraulic stimulation, production (T = 150°C; Q = ?75 m3 h?1; C = 265 g l?1) and injection (T = 70°C; Q = 75 m3 h?1; C = 265 g l?1) change the HT conditions of the geothermal reservoir. The most significant changes affect temperature, mass concentration and pore pressure. These changes influence fluid density and viscosity as well as rock properties such as porosity, permeability, thermal conductivity and heat capacity. In addition, the geometry and hydraulic properties of hydraulically induced fractures vary during the lifetime of the reservoir. A three‐dimensional reservoir model was developed based on a structural geological model to simulate and understand the complex interaction of such processes. This model includes a full HT coupling of various petrophysical parameters. Specifically, temperature‐dependent thermal conductivity and heat capacity as well as the pressure‐, temperature‐ and mass concentration‐dependent fluid density and viscosity are considered. These parameters were determined by laboratory and field experiments. The effective pressure dependence of matrix permeability is less than 2.3% at our reservoir conditions and therefore can be neglected. The results of a three‐dimensional thermohaline finite‐element simulation of the life cycle performance of this geothermal well doublet indicate the beginning of thermal breakthrough after 3.6 years of utilization. This result is crucial for optimizing reservoir management. Geofluids (2010) 10 , 406–421 相似文献
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Erwan Messager Aïcha Badou François Fröhlich Brigitte Deniaux David Lordkipanidze Pierre Voinchet 《Archaeological and Anthropological Sciences》2010,2(1):25-34
Mineralised fruits and seeds are frequently found in archaeological sediments but their chemical nature has not been often
examined. The nature and the origin of these archaeobotanical remains have to be investigated to understand their taphonomic
history. Fruits or seeds can be mineralised not only by replacement mineralisation but also by biomineralisation during the
plant life. The mineral components of three fossil fruits sampled on the Pleistocene site of Dmanisi were analysed and compared
with their modern analogues. Analyses were carried out by means of an environmental scanning electron microscope, equipped
with an energy dispersive X-ray device and by means of a Fourier transform infrared spectrometer. Biogenic carbonates and/or
biogenic silica were identified in the fossil and modern fruits of some taxa. Comparison between fossil and modern specimens
has shown that molecular reorganisation occurred in carbonate and in biogenic silica during fossilisation, through diagenetic
processes. The resulting stable mineral structures confer an exceptional preservation to fruits in sediments. Taking into
account these taphonomic specificities (transformation and differential preservation), the chronological and palaeoenvironmental
aspects of the mineralised fruits are discussed. 相似文献
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Paul Benneworth Lars Coenen Jerker Moodysson Björn Asheim 《European Planning Studies》2009,17(11):1645-1664
Universities are increasingly seen as potential contributors to regional innovative capacity by serving as local knowledge conduits, bringing global state-of-the-art science and technology into the region. In practice, however, more active university engagement with their regional innovation systems is not as straightforward as it may seem. The article uses examples from a successful case by which less successful regions could be inspired. Our analysis considers how various forms of technological learning intersecting within Lund University around three distinct sectoral engagement efforts have been built up and how this created new structural regional innovation capacity. 相似文献