Waveguide theory is suggested for the analysis of UHF radiation in urban microcellular environments, where both the transmitter and the receiver are below rooftop level. The delay profile is calculated from the steady state power distribution among the modes of the waveguide. The delay profile is very asymmetrical because most of the power is contained in the low order (faster) modes, and becau...

This paper presents an explicit formula for propagation path loss prediction of microcellular communication in an urban street scene. The formula is derived based on geometrical optics and diffraction theory and it takes into account multiple reflections along main streets, side streets and diffractions around corners. Comparisons between our theoretical results with measurements and ray tracin...

The demand for ever-increasing wireless data transmission rates and throughput area-densities, especially with regard to microcellular networks, internet access, back-hauling, inter-device transmission, sensing applications, has spurred the exploration of new spectra in millimeter-wave (30–300 GHz) terahertz bands (0.1–10 THz), study techniques multi-Gigabit based on very high-gain antennas [it...

The effect of yeast strain and aging time on the chemical composition, analytical, and sensory foam properties of sparkling ciders has been studied. The analytical foam parameters (foamability, HM; Bikerman coefficient, sigma; and foam stability time, T(s)) were significantly influenced by aging and yeast strain. The sensory attributes (initial foam, foam area persistence, bubble size, foam col...

foaming conditions of the red beet (beta vulgaris l) puree were optimized using response surface methodology (rsm) with respect to arabic gum concentrations (0.01 – 0.4% w/w), red beet puree (40 _ 60% w/w),egg white concentration( 5 _ 15% w/w) and whipping time (3 – 9 min) for minimum foam density and foam drainage volume as response variables. foams were prepared from various pulp concentratio...

As minimum device dimensions continue to shrink and on-chip device densities grow, signal distortion caused by capacitive coupling and crosstalk between the interconnections will increase. The current insulator material for on-chip applications is silicon dioxide (k= 3.9 4.2). The next generations of microchips require interlayer dielectrics with dielectric constants below 2.2 [I, 21. Although ...

Programmable Anisotropic Transformations In article number 2105024, Joanna Aizenberg, Katia Bertoldi, and co-workers report that by programming independently anisotropy at the molecular structural levels, unprecedented director-determined symmetry breaking can be realized in microcellular structures made of liquid crystalline elastomers (LCEs). These exploited to achieve switchable direction-de...

The foam generated by the mixture of air and water has a much higher viscosity and lower mobility than those of pure water or gas that constitutes the air-water foam. The possibility of using the air-water foam as a flow barrier for the purpose of groundwater and soil remediation is explored in this paper. A nanoparticle-stabilized air-water foam was fabricated by vigorously stirring the nano-f...

Three heat resistant cross-linked PVC foam plastics were prepared and their performances were compared with universal cross-linked PVC structural foam. The results show that these three heat resistant foams have higher glass transition temperatures (close to 100 °C) than universal structural foam (83.2 °C). Compared with the universal structural foam, the three heat resistant foams show much hi...

A ray tracing model based on the application of the uniform theory of diffraction (UTD) and geometrical optics (GO) for modeling the propagation in the microcellular urban scenarios has been implemented. This model has been used to analyze the behavior of the rms delay spread while turning a corner in two street-corner environmentsregular and chaflane street corners. The study of the environmen...