Conjugated polymers and copolymers have been known to have electroluminescent properties for a number of years. This study examines the electroluminescent properties of a particular segmented block copolymer. This copolymer uoresces quite well both in solution and as a thin lm, but a single layer organic LED made from it does not work well. I investigate the e ect of blending 1% PAN/CSA into th...

Developing correlations between various soil parameters are considered the major challenge to diminish time and cost associated with field measurements. Soil hydraulic and physical properties were extensively characterized using tension disc infiltrometer and soil sampling in a silty clay agricultural field in Kalaat El-Andalous, Tunisia. Tension disc infiltrometer experiments were conducted at...

Southern California kelp forests experienced major losses during the El Nino of 1957-1959. The proximal reason for the decline was ascribed to sea urchin grazing, and the eventual recovery of some forests followed sea urchin control efforts, kelp restoration, and improvements In sewage disposal practices. The very strong El Nirio of 1982-84 allowed us to reexamine hypotheses regarding the inter...

Adv. Mater. 2009, 21, 1–5 2009 WILEY-VCH Verlag Gmb We demonstrate print-deposition of high resolution, patterned, multicolored thin films of luminescent colloidal quantum dot (QD)-polymer composites and use the printed patterns in fabricating robust, bright, full-color AC-driven displays. The benefits of AC electroluminescent (EL) displays include simple, low-cost fabrication and high reliabil...

E C O N O M I C R E V I E W Third Quarter 2006 Since Ecuadorian president Jamil Mahuad announced the adoption of the U.S. dollar as legal tender in January 2000, the discussion about the pros and cons of full dollarization has intensified. In 2001 El Salvador engaged in full dollarization to enhance its economic reform process. The two economies adopted the U.S. dollar as their currency for dia...

Aims. We present the first results of a polarimetric survey of main-belt asteroids at Complejo Astronómico El Leoncito (Casleo), San Juan, Argentina. The aims of this survey are to increase the database of asteroid polarimetry, to estimate diversity in polarimetric properties of asteroids that belong to different taxonomic classes, and to search for objects that exhibit anomalous polarimetric p...

The work presented here is a study of thermally enhanced injection in light-emitting diodes (LEDs). This effect, which we refer to as "thermal pumping", results from Peltier energy exchange from the lattice to charge carriers when current is injected into an LED. For an applied voltage V such that qV < (hw), where q is the electron charge and (hw) is the average emitted photon energy, thermal p...

A high-sensitivity mechano-luminescent sensor was fabricated on the basis of piezoelectric/electroluminescent composites. The working principle of this mechano-luminescent sensor was elucidated by analyzing the relationship between the piezoelectric-induced charges and the electroluminescent effects. When a stress is applied on the piezoelectric layer, electrical charges will be induced at both...