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Abstrakt

The paper proposes a list of five „stylized facts”, regarded as the main trends with respect to the development of the global economy in the 20th c. The author’s main purpose is to answer the question whether, in the light of the contemporary growth theory and demographic forecasts, these trends are likely to continue unchanged also in the 21st c. Taking into account this theory and those forecasts, the paper offers forecasts of the average GDP per capita for both the countries of the Technology Frontier Area (TFA) and the catching-up countries. By these forecasts, the strong divergence trend of the last two centuries will be replaced by a strong convergence trend during the 21st c. Moreover, the global rate of growth of the per capita GDP will continue to be high in the first half of the current century, but strongly declining in the second half.
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Abstrakt

The aim of the paper is to measure and forecast concentration of regional development potential on a regional basis. The study covered 14 GUS features, which measure the development potential. The forecast, nominal values and processes’ dynamics were calculated for data from 2010 to 2020, using author made method. The study reveals that key factors determining the diversification of the distribution of the potential include the relation of large agglomerations to their regional surroundings. Therefore, we are dealing with growth poles with different impact levels. Since 2010, the process of concentrating potential in Poland has taken different directions. In poorly developed regions, we observe constant distribution values. Most regions, especially those with medium and high levels of economic development, are characterized by a dynamic increase in the level of concentration 5% to 6% annually. This means that the growth poles «move away» from their surroundings and strengthen their position. Simultaneously, they slightly reduce the distance to the strongest developed region in Poland (Mazowsze). By 2020, these trends will remain unchanged, however regions with a moderately low level of development will observe the fastest growth.
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The double barrier separate confinement heterostructure (DBSCH) design aimed at reduction of vertical beam divergence and increase of catastrophic optical damage (COD) level for high power laser diodes (LDs) operation is presented. Insertion of thin, wide-gap barrier layers at the interfaces between waveguide and cladding layers of SCH gives an additional degree of freedom in design making possible more precise shaping of the optical field distribution in the laser cavity. By comparison with the large optical cavity (LOC) heterostructure design it has been shown that the low beam divergence emission of DBSCH LDs can be attributed to the soft-profiled field distribution inside the cavity. This ‘soft mode profile’ seems to determine narrow laser beam emission rather than the field distribution width itself. The potential problem with the soft-profiled but relatively narrow (at half-maximum) mode distribution is a lower COD level. Widening of the mode profile by the heterostructure design corrections can increase it, but care must be taken to avoid excessive decrease of confinement factor (Γ). As a result it is shown that DBSCH design is possible, where the low beam divergence and high COD level is achieved simultaneously. Wide stripe gain-guided LDs based on GaAsP/AlGaAs DBSCH SQW structures have been manufactured according to the design above. Gaussian-shaped narrow directional characteristics are in relatively good agreement with modelling predictions. Vertical beam divergences are 13–15o and 17–18o FWHM for design versions experimentally investigated. Threshold current densities of the order of 350–270 Acm-2 and slope efficiencies of 0.95 and 1.15 W/A have been recorded for these two versions, respectively. Optical power at the level of 1 W has been achieved. The version with lower beam divergence proves to be more durable. Higher optical power levels are to be obtained after heterostructure doping optimisation.
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Abstrakt

On January 14, 2011, Zayn al-‘Ābidīn Bin ‘Alī resigned, left Tunisia and took refuge in Saudi Arabia following the revolts born in Sīdi Būzīd after the suicide of Bū-‘Azīzī. The Arab Spring in Tunisia was not a popular uprising perpetrated by the lower class and the unemployed young people: the committees of the lawyers and the magistrates who joined the protests, proved the active participation of the middle class. However, the Revolution did not alleviate the popular unrest, and it did not reduce the social imbalances. The diastratic varieties, already existing before the Revolution, are the linguistic reflection of the social situation. After 2011 the main actors of the protests, proceeding from the lowest and youngest class, came back to the Ḥū ma, the ghetto, in which anger and frustration flourish. The description of the life in the Ḥūma, has become the main topic of many songs written by the new generation of Tunisian artists who sing in the slang of the lower class. Despite they proceed from the upper class, they have become the spokesmen of the malaise that hovers in the poor neighborhoods. Guerrero (2012) analysed linguistically Rāyǝs lǝ-Blād, a song by the Tunisian rapper El Général, appeared on internet on February 8th, 2011, few days before the escape of Bǝn ԑAlī. Rāyǝs lǝ-Blād is an example of the artistic denunciation of the political oppression and the social degradation. The songs of artists such as Kafon, Hamzaoui Med Amin and Balti, which appeared after the Revolution instead, are not acts of protest, they just represent the ordinary life of the ūlād ǝl-Ḥūma in the ghetto. What linguistic dynamics are put in place by these singers? After a historical-etymological reconstruction related to the word Ḥūma, it will be shown how this group of artists practiced, on the one hand, the divergence with respect to the prestigious variety of the capital, on the other, the convergence towards the language of the tunisian poorest class.
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