In this work, two different laser dye solutions were used to host highly-pure silicon nitride nanoparticles as scattering centers to fabricate random gain media. The laser dye was dissolved in three different solvents (ethanol, methanol and acetone) and the final results were obtained for methanol only. The silicon nitride nanoparticles were synthesized by dc reactive magnetron sputtering technique with average particle size of 35 nm. The random gain medium was made as a solid rod with high spectral efficiency and low production cost. Optical emission with narrow linewidth was detected at 532-534 nm as 9 mg of silicon nitride nanoparticles were added to the 10 -5 M dye solution. The FWHM of 0.3 and 3.52 nm was determined for Rhodamine B and Coumarin 4800, respectively. This is good attempt to fabricate and operate high-efficient and low-cost random laser in the green region of electromagnetic spectrum.
A spectrophotometric reliable, rapid and sensitive method has been developed and validated for the determination Ketotifen fumarate . A method was described for the determination of Ketotifen Fumarate in pure form or pharmaceutical formulations, a colored ion-pair complex formation reaction among ketotifen fumarate and acid-dye bromophenol blue at pH 3.0 was used for the colorimetric determination of the drug. The complex formed was extracted into chloroform and the maximum absorbance of the solution was measured at 413 nm against blank. The calibration curve calculated obey Beer's law over the concentration range of 0.4-16 μg/ml and the regression equation was A=0.069
... Show MoreA simple and sensitive spectrophotometric method is described for the determination of diclofenac sodium (DCL), in pure form and pharmaceutical formulations. The method is based on the oxidation of 2,4-dinitrophenylhydrazine (2,4-DNPH) and coupling of the oxidized product with DCL in alkaline medium to give intensively colored chromogen which exhibits maximum absorption (λmax) at 600 nm, and the concentration of DCL was determined spectrophotometrically. The optimum reaction conditions and other analytical parameters were evaluated. In addition to classical univariate optimization, modified simplex method (MSM) has been applied in optimization of the variables affecting the color producing reaction. Beer’s law is obeyed in the
... Show MoreSimple and sensitive kinetic methods are developed for the determination of Paracetamol in pure form and in pharmaceutical preparations. The methods are based on direct reaction (oxidative-coupling reaction) of Paracetamol with o-cresol in the presence of sodium periodate in alkaline medium, to form an intense blue-water-soluble dye that is stable at room temperature, and was followed spectrophotometriclly at λmax= 612 nm. The reaction was studied kinetically by Initial rate and fixed time (at 25 minutes) methods, and the optimization of conditions were fixed. The calibration graphs for drug determination were linear in the concentration ranges (1-7 μg.ml-1) for the initial rate and (1-10 μg.ml-1) for the fixed time methods at 25 min.
... Show MoreA simple, precise, and sensitive spectrophotometric method has been established for the analysis of doxycycline. The method includes direct charge transfer complexation of doxycycline withp-Bromanil in acetonitrileto form a colored complex. The intensely colored product formed was quantified based on the absorption band at 377 nm under optimum condition. Beer’s law is obeyed in the concentration range of 1–50 μg.mL-1 with molar absorptivity of 1.5725x104 L.mol-1.cm-1, Sandell's sensitivity index (0.0283) μg.cm-2, detection limit of 0.1064 μg.mL-1, quantification limit 0.3224 μg.mL-1 and association constant of the formed complex (0.75x103). The developed method could find application in routine quality control of doxycycline and has
... Show More
(2)
The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell. Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with
... Show More
(6)
Porous silicon (PS) layers are prepared by anodization for
different etching current densities. The samples are then
characterized the nanocrystalline porous silicon layer by X-Ray
Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier
Transform Infrared (FTIR). PS layers were formed on n-type Si
wafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2
current density for fixed 10 min etching times. XRD confirms the
formation of porous silicon, the crystal size is reduced toward
nanometric scale of the face centered cubic structure, and peak
becomes a broader with increasing the current density. The AFM
investigation shows the sponge like structure of PS at the lower
current density porous begi
(2)
Means of communication has a great impact on all fields of awareness including health awareness by increasing the knowledge of community about health and developing their abilities to improve human health and cultural awareness. According to the importance of health awareness for a community to develop their intellectual and physical integrity, the researcher has found that it is essential to know the role of means of communication as a source of information for many students being active and main segments to build their society intellectually, socially and economically.
The research has focused on the study of health awareness among students and their health knowledge derived from the means of communicat
... Show More
(2)
In dealing with media management phenomenon, concept and elements, we have tried, as much as possible, to build an abstract concept that can be analyzed and measured by analyzing the elements and components of the concept mentioned and explain it.
Before further consideration of the management of media campaigns, it is necessary to restore some points of media management so as not to understand the subject of campaign management as if it is independent of the concept of media management and the objectives that we seek to ensure its achievement. As we have noted that the concept of media management frames the administration mentioned as:
- Authority to manage the media institution.
- Operations supervised by the me
... Show More
(1)
The current research seeks to shed light on the role that social media can play, through the optimal use of it by students, in achieving academic excellence. The most prominent aims that constitute it are:Identifying the social sites most used by students; learning how students interact with the published study material on communication sites and benefit from them to achieve their academic excellence; and knowing the connection between using social media and achieving academic excellence, and the role that these sites play in achieving academic excellence.That incorrect use by students leads to adverse results, and thus affects their academic level. Failure of parents to monitor their student’ use of social media leads
... Show More
To track scientific developments and achievements, for example, that (achieved) after the Second World War until this moment, make each of us in absolute amazement. He invented the computer, discovered the genetic factor (DNA), and discovered the drawing of the human genetic map, going up to the moon, penetrating outer space by satellites, getting close to distant planets, producing jet planes, microprocessors, and lasers, in addition to enabling a person to create a layer of The material is extremely thin and extremely imaginative. It has also become possible for a person to "dig lines that do not exceed 20 billion meters of thickness." The human being was also able to collect things an atom and build an efficient and high-precision con
... Show More