An electronic tongue system was tested as a fast and efficient analytical tool for flavor evaluation of soybean genotypes. Grain samples of 25 soybean lines were analyzed using 0.25 g of milled samples added to 100 mL of distilled water and mixing for one minute on a magnetic stirrer. An aliquot (50 mL) from the filtered liquid was used for the analysis on a pre-fixed frequency of 1 kHz and alternate tension of 50 mV. Two analyses were conducted in a complete randomized design with three replicates. Electrical response (capacitance) of eight polymeric chemical sensors used to analyze the soybean lines were submitted to Principal Component Analysis (PCA). In the spatial distribution of the PCA graphic, the lines close to each other were similar, while the distant ones showed different characteristics. The electronic tongue system was efficient in discriminating flavor of soybean lines.

This work shows a comparative study of organic light emitting diodes based on four different europium complexes with the general formula, Eu(CLs)3bipyridine, where the central ligands are DBM [tris(dibenzoylmethane)], TTA [tris(1-(2-thieneyl)-4,4,4-trifluoro-1,3-butanedione)], NTA [tris(1-(2-naphthoyl)-3,3,3-trifluoroacetone)] and BTA [tris(1-(2-benzoyl)-3,3,3-trifluoroacetone)]. All devices have a driving voltage of 14–16 V, a very low electrical current at normal operation (less than 1 mA) and a good Wall Plug Efficiency (up to near 10−3%). The most suitable central ligand was found to be DBM, with an optical power up to 200 nW (at 612 nm). The BTA exhibits the lowest stability under high applied voltages. The other central ligands have similar results among them. The electroluminescence spectra clearly show the europium ion transitions (with a strong 5D0 → 7F2 line) with a CIE color coordinate around (0.56, 0.34).

The adduct TRIMEB:Eu(BTA)3 · 2H2O was prepared and primarily characterized by photoluminescence (PL), and compared with free Eu(BTA)3 · 2H2O. Both spectra show the Eu3+ ion emission, with subtle differences between lines for the free and encapsulated complex. The temperature dependence and chemical stability were studied, taking into account (in the latter case) the PL changes with time. The use of this new material as the emissive layer in OLEDs was tested by its successful incorporation into a device, using a conductive polymer as host. The use of the TRIMEB adduct increased the stability of the device (as compared with the free Eu complex).

In this work, a ruthenium hexafluorophosphate complex, [Ru(bpy)3](PF6)2 in poly(methylmethacrylate) (PMMA) was employed to build a single layer light electrochemical cell on indium tin oxide polyester flexible substrate. The electroluminescence spectrum features a relatively broad band peaked near 625 nm, with CIE (x, y) color coordinates of (0.61, 0.39). The driving voltage is only 3 V, and for the maximum electrical current of 10 mA the brightness reaches 1 cd/m2. Regarding the useful application of the device, its opto-electrical behavior under mechanical strain was studied considering the central curvature. In these situations, both electrical characterization in DC mode and luminance were analyzed.

This work shows the luminescence properties of a rare-earth organic complex, the Tb(ACAC)3phen. The results show the 5D4 -> 7F3,4,5,6 transitions with no influence of any ligand emission. The photoluminescence excitation spectrum is tentatively interpreted by the ligands absorption. An OLED was made by thermal evaporation (total thickness of 1200 Å) using TPD and Alq3 as hole and electron transport layers, respectively. The light emission reproduces the photoluminescence spectrum of the terbium complex at room temperature, with CIE (x,y) color coordinates of (0.28, 0.55). No presence of any bands from the ligands was observed. The potential use of this compound in efficient devices is discussed.