The paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.72) at the same thickness & concentration of the sample.
The real and imaginary part of complex dielectric constant for InAs(001) by adsorption of oxsagen atoms has been calculated, using numerical analysis method (non-linear least square fitting). As a result a mathematical model built-up and the final result show a fairly good agreement with other genuine published works.
There is no doubt that optical fiber technology is one of the most important stages of the communications revolution at all and it is of utmost importance in our daily life. In this work, five fibers with core radii 2.5, 4.5 and 6.5–8.5 μm were designed. The properties of all guided modes have been calculated at a wavelength of 1550 nm by using RP Fiber Calculator. A single-mode fiber is obtained when the core radius approaches the wavelength. As the core radius is increased, the fiber becomes a multimode. The percentage power in the core increases with increasing core radius. The modes profiles were illustrated and compared with the modern references.
The developments and transformations taking place in the era and the growth of knowledge economies and communication technology led this development to compel higher education institutions in Iraq to reconsider their objectives to keep pace with development. And one of the most important tools of development was the application of e-learning standards and its long-term impact on the performance of the educational institution. Performance auditing plays an important role in verifying the extent to which these institutions have implemented their activities and programs that auditing performance by adopting e-learning standards helps the institutions’ management by providing appropriate information on the extent to which they achieve thei
... Show MoreSoil is considered one of the main factors of subsidence phenomena which
became continually happen in Baghdad (Ghazalia, Ameria, and Hay al-Amyl)
causing bad effects as shortage of drinking water, traffic jam and formation
swamps.
This thesis depends on soil study to a depth 15 meters, due to its
importance in subsidence. This done through specifying its chemical physical
properties.
Soil within Iraq climate, in case of water stopping for any reason it contract
and shrink away especially when it exposed to high pressure these factors
finally caused subsidence. In case of leakage underground water or that of
damaged water pipes this will contribute to chemical reactions which damage soil
structure and incr
This work studies with produce of light fuel fractions of gasoline, kerosene and gas oil from treatment of residual matter that will be obtained from the solvent extraction process as by product from refined lubricate to improve oil viscosity index in any petroleum refinery. The percentage of this byproduct is approximately 10% according to all feed (crude oil) in the petroleum refinery process. The objective of this research is to study the effect of the residence time parameter on the thermal cracking process of the byproduct feed at a constant temperature, (400 °C). The first step of this treatment is the thermal cracking of this byproduct material by a constructed batch reactor occupied with control device at a selective range of re
... Show MoreThe present research has investigated the effect of microwave energy on improving the flow properties of heavy crude oil. The fragmentation of crude oil molecules was carried out with and without using 1 and 10 wt. % concentration of various types of H-donors like tetralin, cyclohexane, and naphtha. Microwave power of 320, 385, and 540 W and radiation time 1-9 min, and temperature were studied. The kinematic viscosity and asphaltene content were measured for evaluation the improving of heavy crude oil.
Results show that viscosity of crude oil decreased with increase H-donor concentration, a maximum percentage of viscosity reduction was10.63 % for tetralin at 6 min radiation time, while 8.67%, and 7.34% for cycl
... Show MoreFlaxseed from the flax plant (Linum usitatissimum), which has been cultivated for domestic use since prehistoric times. This study aims to investigate presence of antibacterial effect of flaxseed extract against selected oral pathogen in-vitro.
Background: The aims of this study were to evaluate the effect of implant site preparation in low-density bone using osseodensification method in terms of implant stability changes during the osseous healing period and peri-implant bone density using CBCT. Material and methods: This prospective observational clinical study included 24 patients who received 46 dental implants that were installed in low-density bone using the osseodensification method. CBCT was used to measure the bone density pre- and postoperatively and implant stability was measured using Periotest® immediately after implant insertion and then after 6 weeks and 12 weeks postoperatively. The data were analyzed using paired t-test and the probability value <0.05 was conside
... Show MoreThe current study was conducted to determine the sensitivity of some pathogenic bacterial isolates isolated from wounds and burns water toward the disposer of the Yas Rue tested five crude bacterial isolates isolated from wounds and burns which these isolates sensitive to aqueous extract crude