Extensional flow of nematic liquid crystal under electric field gradient

Systematic asymptotic methods are used to formulate a model for the extensional flow of a thin sheet of nematic liquid crystal. With no external body forces applied, the model is found to be equivalent to the so-called Trouton model for Newtonian sheets (and fi bers), albeit with a modi fied "Trouton ratio". However, with a symmetry-breaking electric field gradient applied, behavior deviates from the Newtonian case, and the sheet can undergo fi nite-time breakup if a suitable destabilizing field is applied. Some simple exact solutions are presented to illustrate the results in certain idealized limits, as well as sample numerical results to the full model equations.

Bosnia and Herzegovina’s cross border cooperation: applying typologies and revising histories

Aquest document amplia el treball realitzat per Oliveras, durada i Perkmann en l'estudi de la cooperació transfronterera (CBC) a Europa. S'argumenta que el catàleg de les transferències regions (CBR), desenvolupat per Oliveras, durada i Perkmann el 2010, ha d'incloure la CBR que han sorgit com a resultat de l'ampliació actual de la UE en l'Oest Balcans. També serveix per donar suport a la opinió que una quarta etapa en la història desenvolupament de CBC a Europa encara no ha començat. El document porta el CBC de Bòsnia i Hercegovina en el marc de l'Instrument d'Ajuda Preadhesió (component II) com un estudi de casos i classifica cada CBC d'acord amb la tipologia que estableix Oliveras, durada i Perkmann. L'anàlisi revela que una forma de multi-nivell govern (MLG) també està sorgint en aquestes noves CBR. El tipus de MLG és també classificats. La conclusió de l'article és que el procés actual de la UE l'ampliació ha creat dos CBR i MLG promogut en els Balcans Occidentals

Flexible employment and cross- regional adjustment

Employment flexibility is commonly associated to greater labour mobility and thus faster cross-regional adjustments. The literature however offers very little hard evidence on this and quite limited theoretical guidance. This paper examines empirically the relationship between employment flexibility and cross-regional adjustment (migration) at the regional and local levels in the UK. Employment flexibility is associated to higher labour mobility (but only at a rather localised scale) and at the same time seems to reduce the responsiveness of migration to unemployment. This suggest that rising flexibility may be linked to higher persistence in spatial disparities, as intra-regional adjustments are strengthened while extraregional adjustments weakened. Keywords: Employment flexibility, regional migration, labour market adjustment JEL Codes: R11, R23, J08, J61

Is real GDP stationary? Evidence from a panel unit root test with cross-sectional dependence and historical data

We use historical data that cover more than one century on real GDP for industrial countries and employ the Pesaran panel unit root test that allows for cross-sectional dependence to test for a unit root on real GDP. We find strong evidence against the unit root null. Our results are robust to the chosen group of countries and the sample period. Key words: real GDP stationarity, cross-sectional dependence, CIPS test. JEL Classification: C23, E32