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As the interest toward communication-based vehicle safety applications is increasing, the development of secure wireless communication techniques has become an important research area. In this context, the article addresses issues that are related to the use of the visible light communication (VLC) technology in vehicular applications. Thus, it provides an extensive presentation concerning the main challenges and issues that are associated to vehicular VLC applications and of some of the existing VLC solutions. Moreover, the article presents the aspects related to the design and intensive experimental evaluation of a new automotive VLC system. The experimental evaluation performed in indoor and outdoor conditions shows that the proposed system can achieve communication distances up to 50 m and bit error ratio (BER) lower than 10&minus, 6, while being exposed to optical and weather perturbations. This article provides important evidence concerning the snowfall effect on middle to long range outdoor VLC, as the proposed VLC system was also evaluated in snowfall conditions. Accordingly, the experimental evaluation showed that snowfall and heavy gust could increase bit error rate by up to 10,000 times. Even so, this article provides encouraging evidence that VLC systems will soon be able to reliably support V2X communications.

Application and implementation of Internet of Things principles promise to radically change our regular lifestyle. Beyond the tempting facilities offered by smart home appliances, this work proposes some innovative medical applications of Internet of Things Relevant aspects related to the structure of a system based on brainwave interfaces, the results obtained so far, as well as the high complexity of these systems were analyzed. Besides, in the current and especially the future technological context, a new challenge - independent green energy, was introduced. Capturing and recovering the energy from ambient EMF will be the“ zero-power” solution of sensor networks, already recognized as one of the most important technologies for real-world deployment of Internet of Things systems.

In this paper the novel high-temperature resistant polymers with nonlinear optical properties have been synthesized, characterized and tested for use in electro-optical components with high bit rate optical signal processing systems and for dynamic holography. The characterization that has been reported include the measurement of second-order nonlinear susceptibility by second harmonic generation, UV-VIS spectroscopy, XRD measurement dielectric relaxation, glass transition temperature and molecular weight distribution before and after artificial ageing. Also, we have done AFM investigations and profilometry measurements for stamp patterning layers. The application of the new polyimides for electro-optic devices has been evaluated by creation of thin oriented polymer films on various substrates and preparation of planar and strip waveguides.

Spinel-type semiconductor compounds represent an alternative for robust and inexpensive detection systems, due to their good thermal and chemical stability in operation. The sensing mechanism is based on the change in electric resistivity when exposed to specific gaseous ambient, resulting from chemical reactions between metal-oxide surface and gas molecules. Sample composition and morphology are key factors in determining the selectivity and sensitivity of solid-state sensors. In this work structural, morphological and sensory characteristics of some porous oxide semiconductors with spinel-type structure (Nk 0.99 Co 0.01 Mn 0.02 Fe 1.98 O 4-δ , Li 0.5 Sm 0.1 Fe 2.4 O 4 and Mg 0.9 Sn 0.1 Fe 2 O 4 ) are presented. The self-combustion technique was used to prepare these compounds. This method offers the advantage of obtaining nanosized reproducible and porous ceramics with high specific surface area and exact stoichiometry. Investigated compounds hold promise for high-performance applications in acetone sensors.

The investigation of conversion of new soluble poly( p -phenylenevinylene) (PPV) precursor and PPV patterns by irradiation with UV light of a film is reported. We obtained patterns by this method with well-defined edges and channel width up to 10 μm. Also, it was found that the PPV precursor polymer is a photoresist material. This allows the fabrication of PPV patterns, which can directly act as luminescent structures in organic light-emitting diodes (OLEDs). Using the atomic force microscopy (AFM) technique, investigations on the PPV thin films show that at 200 °C well-defined crystalline domains of PPV are detected, thus indicating the complete transformation of the precursor into the final polymer. The current–voltage characteristics of single and double PPV layer devices indicate that turn-on voltages around 9 and 8 V were recorded for double and single PPV layer devices, respectively. From the electroluminescence–voltage plot, an onset voltage at 10 V is detected for two PPV layers OLED. In addition, we investigate the optical, electrical and EL characteristics of pyrrolo[1,2-a][1,10]phenanthroline derivatives [Leontie L, Druta I, Danac R, Rusu GI. Synth Met 2005;155/1:138; Zugravescu I, Petrovanu M. 3+2 Dipolar cycloaddition. Bucharest: Roman Academic Publishing House; 1987 [in Romanian]; Druta I, Andrei M, Aburel P. Tetrahedron 1998;54:2107; Druta I, Dinica R, Bacu E, Humelnicu I. Tetrahedron 1998;54:10811; Dinica R, Druta I, Pettinari C. Synlett 2000;7:1013; Danac R, Rotaru A, Drochioiu G, Druta I. J Heterocyclic Chem 2003;40:283; Druta I, Danac R, Barbieru R, Tapu D, Andrei M. Sci Ann Al I Cuza Univ Iasi S Chem 2001;IX:149] as potential candidates for OLED applications. In this case, PPV was used as the hole-transport layer (HTL) and pyrrolo[1,2-a][1,10]phenanthroline derivatives, which were spin coated onto PPV, as the emissive layer. The structure of all PPV devices reported in this paper was fabricated using UV light for patterning.

Temperature-dependent d.c. electric conductivity of some recently synthesized organic compounds, stable disubstituted 4-(4-pyridyl)pyridinium ylides, is studied. Thin-film samples ( d = 0.100.80 μm) spin-coated from dimethylformamide solutions onto glass substrates have been used. Organic films with reproducible electron transport properties can be obtained if, after deposition, they are submitted to a heat treatment within temperature range of 297 − 527 K. The studied polycrystalline compounds exhibit typical n -type semiconductor behavior. The activation energy of the electric conduction ranges between 0.59 and 0.94 eV. Some correlations between semiconducting parameters and molecular structure of the organic compounds have been discussed. In the higher temperature range ( T > 400 K), the electron transport in examined compounds can be interpreted in terms of the band gap representation model, while in the lower temperature range, the Mott's variable-range hopping conduction model was found to be appropriate. Some of the investigated compounds hold promise for thermistor applications.

We discuss in this progress report whether the surface investigations, means by ellipsometry, atomic force microscopy, spectroscopy and profilometry of Teflon (polytetrafluoroethlylene - PTFE) thin films deposed by electron sputtering in vacuum on different materials. The substrates materials can be used in bioengineering and medicine applications. We found that the surface morphology and structures properties of Teflon thin films depend of parameters selected in deposition process as deposition rate, substrates temperature, deposition temperature, electron activation energy. This study can be used to improve new medical applications and new optoelectronic devices. Recent reports in transfer cold friction of Teflon thin film layers are discussed in the context of material requirements for such special applications because the formation of or oriented networks gives new benefits of the surface obtained.

Mobile and at-home healthcare systems are becoming increasingly important due to the current hospital crowding and long access-time to health services. The use of modern information and communication technologies in health applications and the development of low-cost medical equipment appropriate to personal and home use are among the top research priorities worldwide. In this paper, we present the design and implementation of a novel wireless electrocardiography device which is user-friendly, low cost and low power consumer, and has a high degree of interconnectivity with terminals such as smartphone, laptops, tablets and PCs. These features make it appropriate for mobile and at-home healthcare applications.

Thermally stimulated processes have been studied in thin films of phenanthroline derives to describe the states that had been localized. Ultraviolet Photoelectron Spectroscopy had checked out before thin films of new pyrrolo[l,2-a][l,10] phenanthroline derivatives [1], in order to further applications in optoelectronic devices. The investigated compounds have an electronic band structure which is due to the substituent (R=NO2, Cl) induced transformations of molecular orbitals. Thermally stimulated discharge currents (TSDC) attested dipolar and charge transport mechanisms. Each TSDC peak has been assigned to elementary processes that are different utilizing in addition dielectric spectroscopy (DES), and the mean trap depths have been approximated from thermally stimulated luminescence (TSL) curves.