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Lead telluride (PbTe) quantum dots, despite being considered as one of the most promising candidates for future photovoltaics owing to their higher multiple exciton generation yields, have received limited attention in solar cell designs due their less explored surface chemistry and high air sensitivity. This study demonstrates the synthesis and characterization of highly crystalline PbTe QDs and their utilization in solution processed solar cells through band alignment engineering. Ultraviolet photoelectron spectroscopy studies showed that the conduction and valence band levels depend strongly on the type of surface ligand utilized for the ligand exchange process. Conduction and valence band levels of tetrabutylammonium iodide (TBAI) and 1,2-ethanedithiol (EDT) treated PbTe QDs with respect to vacuum were measured as -3.73 eV/-4.83 eV and -3.48 eV/-4.45 eV, respectively. The presence of a band offset between the conduction and valence band levels of TBAI and EDT treated layers allowed us to engineer the band alignment in the light absorbing layer. As a result, solar cells where TBAI and EDT ligand treated QDs were utilized in a bilayer cell architecture reached a photo conversion efficiency of 0.65%. [ABSTRACT FROM AUTHOR]

In many countries, engineers are legally required to register to a "licensure" system, which is founded on education and experience criteria and administered by a government body, to use the "engineer" title and offer professional services to the public. In today's globalized world, international alliances such as FEANI, APEC and EMF award engineers with European, APEC and International Professional engineer titles within a framework of mutual recognition of qualifications enabling them to practice outside their own country. This article examines such international licensure systems, particularly their administration processes and registration criteria, and discusses how current licensure procedures in Turkey should be revamped in case of joining an international alliance such as European Union. [ABSTRACT FROM AUTHOR]

The article presents information on system concepts that assists one in designing more innovative software systems. By using system concepts one can simplify the way one determine, handle, and communicate the requirements during software development. The system concept both binds the problem, requirements, and possible solutions and functions. If one don't have time for comprehensive requirements work, try to figure out the system concept. Creating something simple and tangible to help you understand and communicate what your project is all about is often the shortcut that you need. This should be a skill in an requirements engineer's repertoire. The concise description synthesizes the problem's essence, requirements, projected solution, cost and return on investment. System concepts may provide an analogy or metaphor to capture the idea. System concept acts as a project's gist. System concept is a stating point to engineers in many fields. Thus, searching for system concept may be integral to any software development project.