Nanotechnologies in Textiles

Textiles, originally made from natural fiber materials, have thousands of years of history [...

Brand portfolio: product and brand relationship

The importance of brand portfolio: product and brand relationship to companies activities are analyzed in this work. The company’s work result in competitive market depends not only from product, it’s advantages and disadvantages, but also on effective brand portfolio management. The work has four parts. The first part gives the scientific literature analysis of brand portfolio, product and brand relationship. The model of brand portfolio planning is prepared on the second part. The application of theoretic product brand portfolio model is researched in the third part. Findings and guidelines depending on the results of theoretic studies and practice researching are prepared on the last part. Brands play a significant role in developing marketing strategies for specific product categories in a firm. The term “brand portfolio” refers to an organization’s approach to the design and management of its products brands. In particular, brand portfolio decisions are concerned with the number of brands to utilize the role of specific brands and the relationship between such brands. A coherent brand portfolio is a key component of a firm’s overall marketing strategy as it provides a structure to leverage strong brands into other markets, assimilate acquired brands, and rationalize the firm’s branding strategy. Brand extension, umbrella branding, and acquisition give firms an increasingly complex portfolio of brands. This study discusses and shows how firms can develop brand portfolio, and considers the factors that contribute in shaping the brand portfolio. The managerial implications to brand portfolio structure and its developing or reconfigure are also analyzed. Accomplished to theoretic study of brand portfolio prepared the model for brand portfolio planning. The model shows, that for correct brand portfolio it is essential to decide product brand’s conception, choose brand strategy, to attach brand elements to different products and to prepare or adopt the marketing strategy. Accomplished practical research shows, that the theoretic model were approved by analysis of SC “Kalnapilis” brand portfolio. Depending on the results of SC “Kalnapilis” brand portfolio researching were prepared findings and guidelines

Investigation of electromagnetic radiation patterns in the vicinity of cellular base stations

The aim of the paper is to explore emission patterns of mobile base station transmitters, perform measurements of high frequency electromagnetic field distribution around the mobile base station, analyze obtained results and compare them with the exposure limiting levels. First of all a short description of research methodology and equipment that was used for the measurement is given. Analyzed and plotted electromagnetic field flux density distribution around the studied base station shows that the maximal radiation flux density is within the distance range of 300-400 m from the base station. Flux densities at these distances reach 0,2 f..1W/cm2 which are at about 50 times lower than permissible occupational exposure levelsFizikos katedraVytauto Didžiojo universiteta

Effect of Ag nanocube optomechanical modes on plasmonic surface lattice resonances

Noble metal nanoparticles patterned in ordered arrays can interact and generate hybrid plasmonic–photonic resonances called surface lattice resonances (SLRs). Dispersion curves help explain how the Bragg coupling conditions and radiation patterns create dipolar and quadrupolar SLRs, but they assume that the nanoparticles are static structures, which is inaccurate at ultrafast time scales. In this article, we examine how local surface plasmon resonances (LSPRs) supported by cubic Ag nanocrystals are modulated by ultrafast photophysical processes that generate optomechanical modes. We use transient absorbance spectroscopy measurements to demonstrate how the LSPRs of the nanoparticles modulate the SLR of the array over time. Two primary mechanical breathing modes of Ag nanocubes were identified in the data and input into electromagnetic models to examine how fluctuations in shape affect the dispersion diagram. Our observations demonstrate the impact of optomechanical processes on the photonic length scale, which should be considered in the design of SLR-based devices

Synthesis and Electron-Beam Evaporation of Gadolinium-Doped Ceria Thin Films

Gadolinium-doped ceria (GDC) nanopowders, prepared using the co-precipitation synthesis method, were applied as a starting material to form ceria-based thin films using the electron-beam technique. The scanning electron microscopy (SEM )analysis of the pressed ceramic pellets’ cross-sectional views showed a dense structure with no visible defects, pores, or cracks. The AC impedance spectroscopy showed an increase in the total ionic conductivity of the ceramic pellets with an increase in the concentration of Gd2O3 in GDC. The highest total ionic conductivity was obtained for Gd0.1Ce0.9O2-δ (σtotal is 11 × 10−3 S∙cm−1 at 600 °C), with activation energies of 0.85 and 0.67 eV in both the low- and high-temperature ranges, respectively. The results of the X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometer (ICP-OES) measurements revealed that the stoichiometry for the evaporated thin films differs, on average, by ~28% compared to the target material. The heat-treatment of the GDC thin films at 600 °C, 700 °C, 800 °C, and 900 °C for 1 h in the air had a minor effect on the surface roughness and the morphology. The results of Raman spectroscopy confirmed the improvement of the crystallinity for the corresponding thin films. The optimum heat-treating temperature for thin films does not exceed 800 °C

Microstructuring of electrospun mats employing femtosecond laser

Electrospun mats from nano/micro-fibers with control porosity and pore shape may be ideal candidate for tissue engineering scaffolds. In this study three type of poly(vinyl alcohol) (PVA) mats of 48-65 µm thickness with different nano/micro-fibers diameters mostly of 100-200 nm were deposited by electrospinning process. Controlled density porosity in the electrospun mats was introduced by Yb:KGW femtosecond laser micromachining system. The influence of electrospun mat micro structure, the distance between the adjacent laser ablation points, the number of femtosecond laser pulses on quality and structure of laser irradiated holes were investigated. It was demonstrated that the quality of irradiated holes depend on structure of electrospun mats (diameter of nano/micro-fibers, thickness of mats) and femtosecond laser processing parameters. Varying the distance between points and number of applied femtosecond laser pulses it is possible to fabricate electrospun mats with pores of 22-36 μm diameter.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.10249</p

Synthesis and electron-beam evaporation of gadolinium-doped ceria thin films

Gadolinium-doped ceria (GDC) nanopowders, prepared using the co-precipitation synthesis method, were applied as a starting material to form ceria-based thin films using the electron-beam technique. The scanning electron microscopy (SEM )analysis of the pressed ceramic pellets’ cross-sectional views showed a dense structure with no visible defects, pores, or cracks. The AC impedance spectroscopy showed an increase in the total ionic conductivity of the ceramic pellets with an increase in the concentration of Gd2O3 in GDC. The highest total ionic conductivity was obtained for Gd0.1Ce0.9O2-δ (σtotal is 11 × 10−3 S∙cm−1 at 600 °C), with activation energies of 0.85 and 0.67 eV in both the low- and high-temperature ranges, respectively. The results of the X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometer (ICP-OES) measurements revealed that the stoichiometry for the evaporated thin films differs, on average, by ~28% compared to the target material. The heat-treatment of the GDC thin films at 600 °C, 700 °C, 800 °C, and 900 °C for 1 h in the air had a minor effect on the surface roughness and the morphology. The results of Raman spectroscopy confirmed the improvement of the crystallinity for the corresponding thin films. The optimum heat-treating temperature for thin films does not exceed 800 °C

Measurement system for high frequency electromagnetic pollution mapping

Fizikos katedraVytauto Didžiojo universiteta

Wavelength-tailored enhancement of Raman scattering on a resonant plasmonic lattice

Routine single-molecule analysis using surface-enhanced Raman scattering (SERS) is still out of reach using conventional substrates based on corrugated metallic surfaces. Tailoring the substrate to a specific excitation wavelength is an effective way to improve the SERS enhancement factor. Here, we present a comprehensive theoretical and experimental study of wavelength-tailored SERS substrates with improved sensitivity, exploiting the surface lattice resonance (SLR) in a plasmonic lattice comprised of assembled Ag nanoparticles. We tuned the SLR close to 532 nm and evaluated its effect on SERS. We found that SLR-based substrates had 10 times overall higher sensitivity and 100 times higher sensitivity at the target wavelength compared to non-tuned counterparts. Furthermore, we compared monomer and tetramer unit cell cases and found that the combined effect of tuned SLR and hot spots further improves the enhancement factor more than 400 times over a substrate with a random layer of nanoparticles