Radish (Raphanus sativus L. cv. Cherriette), lettuce (Lactuca sativa L. cv. Waldmann's Green), and spinach (Spinacea oleracea L. cv. Nordic IV) plants were grown under 660-nm red light-emitting diodes (LEDs) and were compared at equal photosynthetic photon flux (PPF) with either plants grown under cool-white fluorescent lamps (CWF) or red LEDs supplemented with 10% (30 micromoles m-2 s-1) blue ...

A novel solution processable phosphorescent dendrimer based on cyclic phosphazene (CP) cores has been prepared and used as emissive layers in simple OLED architectures, providing efficiencies of 24.0 cd A(-1) and 16.7 lm W(-1).

Improvement of light extraction efficiency of InGaN light emitting diodes (LEDs) using polydimethylsiloxane (PDMS) concave microstructures arrays was demonstrated. The size effect of the concave microstructures on the light extraction efficiency of III-Nitride LEDs was studied. Depending on the size of the concave microstructures, ray tracing simulations show that the use of PDMS concave micros...

Significant enhancement in the light output from GaN-based green light-emitting diodes (LEDs) was achieved with a hemicylindrical grating structure on the top layer of the diodes. The grating structure was first optimized by the finite-difference time-domain (FDTD) method, which showed that the profile of the grating structure was critical for light extraction efficiency. It was found that the ...

We have theoretically investigated the influence of antireflective sub-wavelength structures on a monolithic white light-emitting diode (LED). The simulation is based on the rigorous coupled wave analysis (RCWA) algorithm, and both cylinder and moth-eye structures have been studied in the work. Our simulation results show that a moth-eye structure enhances the light extraction efficiency over t...

A tapered AlGaN electron blocking layer with step-graded aluminum composition is analyzed in nitride-based blue light-emitting diode (LED) numerically and experimentally. The energy band diagrams, electrostatic fields, carrier concentration, electron current density profiles, and hole transmitting probability are investigated. The simulation results demonstrated that such tapered structure can ...

statement of the problem: various methods such as light emitting diode (led) have been used to enhance the polymerization of resin-based orthodontic adhesives. there is a lack of information on the advantages and disadvantages of different light curing systems. purpose: the aim of this study was to compare the effect of led and halogen light curing systems on the shear bond strength of orthodon...

AIM The aims of this study were to evaluate the prevention of enamel demineralization and the shear bond strength (SBS) of orthodontic brackets bonded with fluoride and no fluoride conventional and self-etching adhesives and to analyze the characteristics of enamel near the bond area using a polarized light microscope (PLM) following demineralization and remineralization cycling (Des Re). MET...

The aim of this study was to investigate in vitro the antibacterial effect of a dentin/enamel adhesive containing MDPB (Clearfil Protect Bond) after curing and to compare it with an adhesive not containing MDPB (Clearfil SE Bond). The antibacterial effect of the cured adhesives was tested on Enterococcus faecalis by the evaluation of growth inhibition in a 48-h microplate direct contact test (D...

background: application of bonding agents (ba) into deep cavities and light curing them might increase pulpal temperature and threaten its health. the purpose of this study was to evaluate temperature rise of pulp by light curing six ba using two different light curing units (lcu), through a dent in wall of 0.5 mm. materials and methods: this in vitro experiment was carried out on 96 slices of ...