Nanoindentation and structural studies of MgO-doped congruent LiNbO3 single crystals

The mechanical properties of undoped and 2.0, 4.0 and 6.0 mol% Mg-doped LN single crystals, grown by the Czochralski technique, have been investigated using nanoindentation studies to understand the mechanical deformation behaviour as doping is increased. This has been correlated with structural investigations by powder XRD analysis and Raman spectroscopy. Powder X-ray diffraction measurements show a slight increase in the lattice parameters as the Mg content is increased in the crystal. The lattice strain developed due to the doping has been calculated by the Williamson-Hall relation. The influence of Mg incorporation on lattice vibrations was analysed using Raman spectroscopy, which indicated no shift in the peak positions with doping, and only slight variation in the intensity and width of the peaks. The grown crystals were subjected to nanoindentation and the Young's modulus and hardness values were obtained by using the Oliver-Pharr method. The results reveal the optimal doping levels of Mg which result in enhanced mechanical strength of lithium niobate single crystals.publishe

Reassessing the effect of colour on attitude and behavioural intentions in promotional activities: The moderating role of mood and involvement

The present research examines the effect of background colour on attitude and behavioural intentions in various promotional activities taking into consideration the moderating role of mood and involvement. Three experiments reflecting different promotional activities (window display, consumer trade show, guerrilla marketing) were conducted for this purpose. Overall, findings indicate that cool background colours, in contrast to warm colours, induce more positive attitudes and behavioural intentions mainly in positive mood, and low involvement conditions. Implications are also discussed

Healthy by design, but only when in focus: communicating non-verbal health cues through symbolic meaning in packaging

Abstract not availableNadine Karnal, Casparus J.A. Machiels, Ulrich R. Orth, Robert Ma

Crystal growth of Ru-doped congruent LiNbO3 and investigation of crystalline perfection and optical properties

Single crystals of undoped and Ru-doped congruent LiNbO3 (LN) were successfully grown by the Czochralski method. The axial and radial gradient of the radio frequency furnace was controlled in order to obtain crack-free single crystals. Wafers were cut from the grown Ru-doped single crystal at different axial positions along the growth direction and subjected to various characterization analyses. Good optical homogeneity and low residual strain in the grown crystal is confirmed by the conoscopy patterns. Further, it is confirmed that Ru doping does not influence the optical sign of the crystal. From a high-resolution X-ray diffractometry analysis, it is evident that the as-grown undoped LN crystal exhibited better crystalline perfection with a single and sharp diffraction curve in comparison to the Ru-doped crystals, which are characterized by a broader diffraction curve. Absorption coefficient and band-gap analysis across the axial length revealed a concentration variation of Ru across the length. Refractive index measurements carried out using a prism coupler showed variation in the optical birefringence, also due to the variation of Ru concentration at different positions of the grown single crystal

IPTV network security: threats and countermeasures

With the increasing popularity of high quality multimedia contents of Internet Protocol Television (IPTV), its attacks and threats are also increasing parallelly. Consequently, it remains an important concern and may arise in various points of IPTV environments, e.g., home and core networks, delivery and management networks, content source, and so forth, To ensure a desired level of security to protect the contents and IPTV networks, multiple layers of security are mandatory. In this chapter, we only cover the security aspects of IPTV delivery networks, and others areout of the scope. Since all the contents of IPTV have to travel through one or multiple networks before reaching to the destination; it inherits all the security vulnerabilities that exist in the TCP/IP networks. Consequently, the basic security measures that are required to protect any TCP/IP network are equally applicable to the IPTV infrastructure. Moreover, several constraints of IPTV-related data also need to be taken into account. Any resilience technique that fails to ensure those constraints will certainly affect the consumer experience; and hence, it is undesirable. In this chapter, we overview all these issues in brief, Moreover, we also briefly mention the countermeasures that would assist to tackle these issues