Abstract: This study aims to investigate the effects of solvents of various polarities on the electronic absorption and fluorescence spectra of RhB and Rh6G. The singlet‐state excited dipole moments (me) and ground state dipole moments (mg) were estimated from the equations of Bakshiev -Kawski and Chamma‐ Viallet using the variation of Stokes shift along with the solvent’s dielectric constant (e) and refractive indexes (n). The observed singlet‐state excited dipole moments were found to be larger than the ground‐state ones. Moreover, the obtained fluorescence quantum yield values were influenced by the environment of the fluorescing molecule. Consequently, the concentration of the dye solution, excited singlet state absorption and

The investigation of the effect of tempering on thermal analysis of
Al-Ti-Si alloy and its composites with MgO and SiC particles was
performed. Thermal analysis was performed before and after
tempering by DSC scan. Optical microscopy was used to identify the
phases and precipitations that may be formed in base alloy and
composites. X-ray diffraction test indicated that the Al3Ti is the main
phase in Al-Ti-Si alloy in addition to form Al5Ti7Si12 phase. Some
chemical reactions can be occurred between reinforcements and
matrix such as MgO.Al2O3 in Al-Ti/MgO, and Al4C3 and Al(OH)3 in
Al-Ti/SiC composite. X-ray florescence technique is used to
investigate the chemical composition of the fabricated specimens.
H

Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic

This study presents a comprehensive set of laboratory works for the examined soil layers extracted from Baghdad city (specifically from Alkadhimya, Alaitaifiya, and Alhurriya) to illustrate their engineering properties. The researchers have adopted the unified soil classification system for soil classification purposes. Also, the direct shear test was performed for soil samples with various degrees of saturation (0%, 25%, 50%, 75%, and 100%). The test results have shown a significant reduction in cohesion property with higher moisture content within soil samples. Also, a noticeable reduction in angle of internal friction value has occurred with such changes. Furthermore, it has been found that the bearing capacity of unsaturated soi

This study was aimed to reduce the amount of the sprayed solution lost during trees spraying.  At the same time, the concentration of the sprayed solution on the target (tree or bush) must be ensured and to find the best combination of treatments. Two factors controls the spraying process: (i) spraying speed (1.2 km/h, 2.4 km/h, 3.6 km/h), and (ii) the type of sensor. The test results showed a significant loss reduction percentage. It reached (6.05%, 5.39% and 2.05%) at the speed (1.2 km/h, 2.4 km/h, 3.6 km/h), respectively. It was noticed that when the speed becomes higher the loss becomes less accordingly. The interaction between the 3.6 km/h speed and the type of Ultrasonic sensor led to a decrease in the percentage of the spray

Background: This in vitro study evaluated the effect of canal dryness and flaring on the accuracy of two electronic apex locators for working length (WL) determination. Materials and methods: Sixty extracted teeth were used, after access opening was done, the occlusal surface was flattened to create stable reference point. The teeth were randomly divided into two equal main groups of flared and unflared group each one of 30 teeth. The flaring was done with Gates Glidden drills. The two main groups were further subdivided into two subgroups: dry canal and wet canal using 5.25% sodium hypochlorite groups, Electronic WL of each sample was determined using both Root ZX and i-Root apex locator. Consequently, histologic WL was determined by shav

In this study, the effect of ceramic coating on the performance and gases emission on diesel engine was investigated. A four-stroke, direct injected, single cylinder, diesel engine was tested at constant speed and at different load conditions without coating. Then, the inlet and exhaust valves faces were coated by about 500µm with ceramic materials. Ceramic layers were made of YttriaStabilized Zirconia (YSZ), and NiCrAl as a bond coat. The coating technique adapted in this work is the flame spray method. The engine with valves ceramiccoated research was tested for the same operation conditions of the engine (without coating). The results indicate a reduction in both fuel consumption by about 7.6% and particulate emissions by about (13

To evaluate the effectiveness of different microwave irradiation exposure times on the disinfection of dental stone samples immersed in different solutions, and its affect on the dimensional accuracy and surface porosity. Dental stone casts were inoculated with an isolate of Bacillus subtilis to examine the efficiency of microwave irradiation as a disinfection method while immersed in different solutions; water, 40% sodium chloride, or without immersion for different durations. Dimensional accuracy and surface porosity were also evaluated. Significant reduction in colony counts of Bacillus subtilis were observed after 5 minutes of microwave irradiation of immersed dental casts in water and NaCl solution. No evidence of growth was observed a

In current research Copper was employed for preparing a ternary system of Al–Si alloy in different (0.2–2.5 wt. %) the best was taken is (1.5%wt) of copper that circumstances of solidification for improving the mechanical performance of the available in aluminium alloy. Cast iron molds were prepared to obtain tensile strength testing specimens. Alloys were prepared by employing gas furnaces. The molten metal was poured into a preheated cast-iron mold. The obtained alloy structures were studied using an X-ray diffractometer and optical microscopy. The mechanical performance of the prepared alloys was examined under the influence of different hardening conditions in both heat and non-heat-treated conditions. The outcomes showed at the

The influence of different thickness (500,750, and 1000) nm on the structure properties electrical conductivity and hall effect measurements have been investigated on the films of copper indium selenide CuInSe2 (CIS) the films were prepared by thermal evaporation technique on glass substrates at RT from compound alloy. The XRD pattern show that the film have poly crystalline structure a, the grain size increasing with as a function the thickness. Electrical conductivity (σ), the activation energies (Ea1,Ea2), hall mobility and the carrier concentration are investigated as function of thickness. All films contain two types of transport mechanisms of free carriers increase films thickness. The electrical conductivity increase with thickness