abstractin this paper, we investigate effect of fe–intermetallic compounds on plastic deformation of closed-cell composite aluminum foam as filler of thin-walled tubes. however, deformation of the aluminum foam-filled thin-walled tubes as crushed-box will be presented in part (ii). composite foams of alsi7sic3 and alsi7sic3-(fe) as closed cell were synthesized by powder metallurgy foaming metho...

the brass tubes with foam cores of alsi7sic3, alsi7sic3fe1 and alsi7sic3fe3 were produced as the crush-boxes with circle and square cross-section. then axial compressive behavior and energy absorption capability of the foam-filled tubes were investigated during the quasi-static progressive plastic buckling. the uniaxial compressive stress–strain curves of the foam-filled brass tubes exhibited t...

in the present work, a prototype of a new type of solar collectors, which called direct absorption solar collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume) were used a...

in this research calcium fluoride nanoparticles and its different amount of cerium ion dopant (5%and 10%) were prepared. the mentioned nanoparticle were studied by fourier transform infrared spectroscopy (ftir) , x-ray diffraction (xrd), absorption and photoluminescence spectra (pl) and scanning electron microscopy (sem). the xrd patterns indicate a typical cubic fluorite structure and no other...

Today, due to qualitative growth and scientific advances, energy, especially electricity is increasingly needed by human society. One of the almost endless and pure energy which have been paid attention over the years is the solar energy. Solar cells directly convert solar energy into electrical energy and are one of the main blocks of photovoltaic systems. Significant improvement has been made...

Fecal energy excretion was measured by bomb calorimetry, in a group of 30 healthy volunteers and 15 patients with tropical sprue, to determine the absorption of nutrient energy. The mean energy absorption in the healthy volunteers (91.6%) was less than in similar subjects in temperate climates. The reduction of energy absorption in the volunteers, who all have tropical enteropathy, suggests tha...

In the present work, KTP crystals have been grown by spontaneous nucleation technique in flux medium using K6P4O13 flux. 0.4-1 °C/h cooling rates were applied in the spontaneous nucleation process. The presence and amount of impurities has been determined by using XRF. The optical transmission spectra of impure KTP crystals in the UV–visible region are discussed. The transmission cut-off is cle...