Browsing by Subject "Emission intensity"

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Open Access
Investigating patterns of carbon convergence in an uneven economy: the case of Turkey
(Elsevier B.V., 2018) Acar, S.; Yeldan, A. Erinç
Turkey is known to suffer from severe volatility in its growth patterns, as well as from the uneven sectoral growth and employment. Volatile rates of emissions across sectors are further manifestations of this uneven structure. The purpose of this study is two-fold: first, we check for dynamic patterns of convergence of carbon dioxide (CO2) emissions across sectors; and second, using evidence from panel data econometrics, we search for the determinants of these processes utilizing macroeconomic explanatory variables. We find that, based on various alternate criteria, CO2 emissions display conditional convergence mainly driven by the business cycle. Furthermore, across sectors, high technology activities display convergence over time; and yet, medium technology sectors that constitute the bulk of the aggregate value added display either poorly convergent or divergent trends. These results reveal that much of the emissions convergence is driven by the business cycle rather than the workings of discretionary mitigation policy.
Open Access
Stable and efficient colour enrichment powders of nonpolar nanocrystals in LiCl
(Royal Society of Chemistry, 2015) Erdem, T.; Soran-Erdem Z.; Sharma, V. K.; Keleştemur, Y.; Adam, M.; Gaponik N.; Demir, Hilmi Volkan
In this work, we propose and develop the inorganic salt encapsulation of semiconductor nanocrystal (NC) dispersion in a nonpolar phase to make a highly stable and highly efficient colour converting powder for colour enrichment in light-emitting diode backlighting. Here the wrapping of the as-synthesized green-emitting CdSe/CdZnSeS/ZnS nanocrystals into a salt matrix without ligand exchange is uniquely enabled by using a LiCl ionic host dissolved in tetrahydrofuran (THF), which simultaneously disperses these nonpolar nanocrystals. We studied the emission stability of the solid films prepared using NCs with and without LiCl encapsulation on blue LEDs driven at high current levels. The encapsulated NC powder in epoxy preserved 95.5% of the initial emission intensity and stabilized at this level while the emission intensity of NCs without salt encapsulation continuously decreased to 34.7% of its initial value after 96 h of operation. In addition, we investigated the effect of ionic salt encapsulation on the quantum efficiency of nonpolar NCs and found the quantum efficiency of the NCs-in-LiCl to be 75.1% while that of the NCs in dispersion was 73.0% and that in a film without LiCl encapsulation was 67.9%. We believe that such ionic salt encapsulated powders of nonpolar NCs presented here will find ubiquitous use for colour enrichment in display backlighting. © The Royal Society of Chemistry 2015.