1. Global Energy Problems and the Role of Renewables 1.1. Energy demand 1.2. Energy, environmental problems and sustainable development 1.3. Water demand and consumption 1.4. Water and energy 1.5. Desalination and energy 1.6. Renewable energy technologies 2. Solar Collectors 2.1. Parabolic trough collectors 2.2. Fresnel collectors 2.3. Parabolic dish reflector 2.4. Heliostat field collector 3. ...

Multiphoton processes in dense atomic vapors such as four-wave mixing or coherent blue light generation are typically viewed from single-atom perspective. Here we study the surprisingly important effect of phase matching near two-photon resonances that arises due to spatial extent of the atomic medium within which the multiphoton process occurs. The non-unit refractive index of the atomic vapor...

The Normalized Difference Vegetation Index (NDVI) has. been an important data product of the AVHRR series of instruments that have flown on the NOAA polar orbiting satellites. This index has been extensively used to monitor global vegetation and to study deforestation. As planning begins for follow-on versions, a proposal has been made to improve the robustness of the index by narrowing the spe...

We propose a paradigm for macroscopic control of high-order harmonic generation by modulating the bound-state population of the medium atoms. A unique result of this scheme is that apart from regular spatial quasi-phase-matching (QPM), also purely temporal QPM of the emitted radiation can be established. Our simulations demonstrate temporal QPM by inducing homogenous Rabi oscillations in the me...

*It is very important to accurately characterize the three-dimensional distribution of water vapor in the atmosphere for the understanding and prediction of mesoscale and storm-scale weather, especially with regard to quantitative precipitation forecasting (Emanuel et al. 1995). Skills in these predictions have been improved rather slowly owing to the high spatial and temporal variability of wa...

We investigate a four-wave-mixing process in an N interaction scheme in Rb vapor placed inside a low-finesse ring cavity. We observe strong amplification and generation of a probe signal, circulating in the cavity, in the presence of two strong optical pump fields. We study the variations in probe field gain and dispersion as functions of experimental parameters with an eye on the potential app...

by performing electrodeless time-resolved microwave conductivity measurements, the efficiency of charge carrier generation, their mobility, and the decay kinetics on photoexcitation were studied in arrays of Si nanowires grown by the vapor-liquid-solid mechanism. Large enhancements in the magnitude of the photoconductance and charge carrier lifetime are found depending on the incorporation of i...

Vapor phase syntheses, including parylene chemical vapor deposition (CVD) and initiated CVD, enable the deposition of conformal polymer thin films to benefit a diverse array of applications. This short review for nanotechnologists, including those new to vapor deposition methods, covers the basic theory in designing a conformal polymer film vapor deposition, sample preparation and imaging techn...

In the vapor phase a solvent-free spectroscopic analysis of dye molecules is applicable [1-3]. For some dye vapors laser action was achieved [1-3]. The dye vapor pressure rises approximately exponentially with temperature. Reasonable vapor pressures (p around 100 Pa = 1 mbar) are obtained for many non-ionic dyes in a temperature region between 200 and 400 °C without considerable thermal decompo...

Recently power generation systems using ammonia-water binary mixtures as a working fluid have been attracting much attention for their efficient conversion of low-grade heat sources into useful energy forms. This paper presents the First and Second Law thermodynamic analysis for a heat recovery vapor generator (HRVG) of ammonia-water mixtures when the heat source is low-temperature energy in th...