In this work, enhancement to the fluorescence characteristics of laser dye solutions hosting highly-pure titanium dioxide nanoparticles as random gain media. This was achieved by coating two opposite sides of the cells containing these media with nanostructured thin films of highly-pure titanium dioxide. Two laser dyes; Rhodamine B and Coumarin 102, were used to prepare solutions in hexanol and methanol, respectively, as hosts for the nanoparticles. The nanoparticles and thin films were prepared by dc reactive magnetron sputtering technique. The enhancement was observed by the narrowing of fluorescence linewidth as well as by increasing the fluorescence intensity. These parameters were compared to those of the dye only and the dye solution hosting nanoparticles without coatings on the cell. For Rhodamine B and Coumarin 102 samples, the fluorescence intensity of coated-cell sample was increased by 230, and 351%, respectively, with respect to that of dye only and by 152 and 141%, respectively, with respect to that of uncoated cells. The full-width at half-maximum (FWHM) was determined for both cases and found to be 8 and 9 nm, respectively.
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The structural, optical and photoelectrical properties of fabricated diffusion heterojunction (HJ) solar cell, from n-type c-Si wafer of [400] direction with Boron, has been studied. AgAl alloys was used because of its properties that affect as a good connection materials. TiO2 has been used as a reflecting layer to increase the absorption radiation. The HJ has direct allowed energy gap equal to 3.1 eV. The c-Si/B HJ solar cell yielded has an active area conversion efficiency of 16.4% with an open circuit voltage of (Voc) 0.592V, short circuit current (Isc) of 2.042mA, fill factor (F.F) of 0.682 and % =10.54.
Abstract. Silver, Indium Selenium thin film with a thickness (5001±30) nm, deposited by thermal evaporation methods at RT and annealing3temperature (Ta=400, 500 and 600) K on a substrate of glass to study structural and optical properties of thin films and on p-Si wafer to fabricate the AgInSe2/p-Si heterojunction solar cell. XRD analysis shows that the AgInSe2 (AIS) deposited film at RT and annealing3temperature (Ta=400, 500 and 600) K have polycrystalline structure. The average grain size has been estimated from AFM images. The energy gap was estimated from the optical transmittance using a spectrometer type (UV.-Visible 1800 spectra photometer). From I-V characterization , the photovoltaic parameters such as, open-circuit voltage, short
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Prediction of accurate values of residual entropy (SR) is necessary step for the
calculation of the entropy. In this paper, different equations of state were tested for the
available 2791 experimental data points of 20 pure superheated vapor compounds (14
pure nonpolar compounds + 6 pure polar compounds). The Average Absolute
Deviation (AAD) for SR of 2791 experimental data points of the all 20 pure
compounds (nonpolar and polar) when using equations of Lee-Kesler, Peng-
Robinson, Virial truncated to second and to third terms, and Soave-Redlich-Kwong
were 4.0591, 4.5849, 4.9686, 5.0350, and 4.3084 J/mol.K respectively. It was found
from these results that the Lee-Kesler equation was the best (more accurate) one
This work deals with determination of optimum conditions of direct diffusion bonding welding of austenitic stainlesssteel type AISI 304L with Oxygen Free High Conductivity (OFHC) pure copper grade (C10200) in vacuum atmosphere of (1.5 *10-5 mbr.). Mini tab (response surface) was applied for optimizing the influence of diffusion bonding parameters (temperature, time and applied load) on the bonding joints characteristics and the empirical relationship was evaluated which represents the effect of each parameter of the process. The yield strength of diffusion bonded joint was equal to 153 MPa and the efficiency of joint was equal to 66.5% as compared with hard drawn copper. The diffusion zone reveals high microhardness than coppe
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Biodiesel production from microalgae depends on the biomass and lipid production. Both biomass and lipid accumulation is controlled by several factors. The effect of various culture media (BG11, BBM, and Urea), nutrients stress [nitrogen (N), phosphorous (P), magnesium (Mg) and carbonate (CO3)] and gamma (γ) radiation on the growth and lipid accumulation of Dictyochloropsis splendida were investigated. The highest biomass and lipid yield of D. splendida were achieved on BG11 medium. Cultivation of D. splendida in a medium containing 3000 mg L−1 N, or 160 mg L−1 P, or 113 mg L−1 Mg, or 20 mg L-1 CO3, led to enhanced growth rate. While u
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Abstract The dissemination of knowledge is no longer confined to schools and universities, not even books. For nearly two centuries, the media have become prominent in disseminating knowledge and culture, in its public and particularly political aspects. After the development of the media from newspapers and magazines to the visual media, their role has increased from the dissemination of abstract information and abstract knowledge towards the process of forming new knowledge through what it publishes and broadcasts from different programs such as drama, news and talk shows. The impact of the media has changed the overall community awareness. Half a century ago the media was not so powerful and widespread. The evolution of the 1990s made
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Some new 2,5-disubsituted-1,3,4-oxadiazole derivatives with azo group were synthesized by known reactions sequence . The structure of the synthesized compounds were confirmed by physical and spectral means .