introduction the significant of solar energy as a renewable energy source, clean and without damage to the environment, for the production of electricity and heat is of great importance. furthermore, due to the oil crisis as well as reducing the cost of home heating by 70%, solar energy in the past two decades has been a favorite of many researchers. solar collectors are devices for collecting ...

Among the renewable sources of energy, solar energy offers a practical solution for the energy problem which is clouding the prospects of mankind. The present paper deals with the experimental investigation of parameters of a solar parabolic trough in winter conditions and to obtain optimum process parameters by Grey Relational Analysis. The experiments were planned using Taguchi’s L9 orthogona...

Solar thermophotovoltaic (STPV) systems convert solar energy into electricity via thermally radiated photons at tailored wavelengths to increase energy conversion efficiency. In this work, we report the design and analysis of a STPV system with 2D photonic crystals (PhCs) using a high-fidelity thermal-electrical hybrid model that includes the thermal coupling between the absorber/emitter/PV cel...

Solar energy is the most “available”, ecological and clean energy. This energy can be used in active or passive mode. The active mode implies the transformation of solar energy into a useful energy. The solar energy can be transformed into thermal energy, using solar collectors. In these collectors, the active and the most important element is the absorber, material which performs the absorptio...

The main objective of the paper is to demonstrate the computer simulation and energy absorption of tapered tubes under impact load. The study of the impact load includes axial compression, bending and torsion. In general, one could rely on the use of finite element analysis to determine the energy absorption capacity of the energy absorbers. This tool is helpful and accuracy. The parametric var...

In this paper, we report the experimental results of a pulsed flash lamped Nd:YAG laser at wavelength of 1064 nm and Qswitched by Cr4+:YAG solid state saturable absorber. We have obtained the output energy (E) and pulse-width ( p τ ) of this laser for various initial transmissions of this saturable absorber. Furthermore, the effect of reflectivity of the output coupler (R), diameter of the rod ...

Unabsorbed pump light in passively Q-switched microlasers leads to suboptimal pulse generation by bleaching the saturable absorber. This mechanism increases the effective unsaturated transmission of the absorber, which leads to a change in the system dynamics that results in increased pulse durations and decreased pulse energies. We report experimental evidence of pump-induced bleaching of the ...

Analytical theory of the high-power passively mode-locked laser with a slow absorber is developed. In distinguishing from previous treatment, our model is valid at pulse energies well exceeding the saturation energy of absorber. This is achieved by solving the mode-locking master equation in the pulse energy-domain representation. The performances of monolithic sub-picosecond blue-violet GaN mo...

We present a new type of transition-edge sensor for single-photon and macro-molecule detection. In our detector the absorber element is an isolated, passive absorber of extremely low thermal mass, maintained close to, but below, its superconducting–normal transition, and strongly inductively coupled to a SQUID sensor. Incoming particles or photons are sensed in terms of a transient change in th...