تم في هذا البحث استخدام المحفز الجديد المصنع من تحميل دقائق البلاتين النانوية على سطح الصفائح النانوية للكرافين كمحفز ضوئي واختباره لدراسة التجزئة الضوئية لملوثات المياه وازالتها بشكل نهائي من مصادر المياه لما لها من تأثير سلبي على البيئة. حيث تم استخدام صبغة البروموفينول الأزرق كمثال على أحد الملوثات. في البدء تم التأكد من تحضير المحفز بالطريقة المستخدمة في طريقة العمل من خلال تشخيصه باستخدام عدد من التقنيات ومنها تقنية المجهر الالكتروني النافذ عالي الدقة، تقنية طاقة تشتت الاشعة السينية الطيفي عن طريق قياس الامتزاز/ الامتزاز باستخدام غاز النتروجين. كذلك تم قياس المساحة السطحية للمحفز المصنع، بالإضافة الى فحص التركيب الكريستال للمحفز باستخدام تقنية حيود الاشعة السينية. وبعد ان تم التأكد من التركيب النهائي للمحفز الضوئي تضمن الجزء الثاني من العمل دراسة قدرة المحفز المصنع على استخدامه في التجزئة الضوئية لصبغة البروموفينول الأزرق تحت الاشعة فوق البنفسجية حيث تم تحضير عدة تراكيز من صبغة البروموفينول الأزرق، تم تشعيع الصبغة بدون وجود المحفز ووجد بان التجزئة الضوئية لم تكن فعالة وبعد ذلك تم استخدام المحفز مع المحلول المائي للصبغة وبتركيز 15 جزء من المليون وأجريت التجارب باستخدام عدة اوزان من المحفز لتحديد افضل وزن يمكن استخدامه من المحفز في كمية محددة من محلول الصبغة ووجد ان 0.01 غرام من الصبغة لكل 250 ملليتر من المحلول المائي للصبغة هو افضل نسبة يمكن الحصول عليها. كما تم اختبار الوسط للتفاعل في الوسطين الحامضي والقاعدي ووجد ان تفكك الصبغة يزداد بشكل ملحوظ في الوسط القاعدي. تم اقتراح ميكانيكية التفاعل التي بينت ان تكون الجذور الحرة لها دور كبير في مهاجمة الاواصر المزدوجة في الصبغة.
Adsorption of Acetone and 2-Butanone on Iraqi siliceouns rocks powder have been investigated. UV technique has been used to determine the adsorption isotherms. The results showed that the adsorption isotherms obeyed Freundlich adsorption equation. The results showed that the adsorption increases with increasing acidity of solutions. The adsorption was exothermic process, increasing temperature leads to decreasing adsorption. H, S, G were calculated
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
... Show MoreHighway embankments stability during its service period represents an important factor for the safety of highway users and vehicles. Consequently, the cost of construction of these embankments should be adequate to maintain the safety and durability during this period through proper estimation of the loading on asphalt pavement, slope stability, horizontal and vertical deformation, etc. Slope stability of the embankment mainly depends on the shear strength of the soil layers materials; this shear strength is affected by the water table level through the contribution of the capillary water. Negative pore water pressure above the water table level evolves matric suction in the unsaturated zone above water table; this matric suction increases
... Show MoreThis work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated from burnt herbs and collected in a smoke generator to delivered through
... Show MoreThe 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
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
... Show MoreThis research study the effect of Titanium dioxide on the tensile properties of
Polystyrene (PS) and Polycarbonate (PC) polymers. The stress – strain curve for pure PS
and pure PC, shows that Young modulus for PS is higher than Young modulus for PC,
because PS have higher ultimate strength than PC.
The addition of TiO2 to PS and PC will reduce the Young modulus and ultimate stress,
because the TiO2 particles will reduces or freeze the orientation of these molecular chain
and reduced the toughness of PC, while when the TiO2 were added to PS, the value of
toughness will be stabilized because TiO2 particles make these chains interlocked and the
mobility of the chains will be restrict.
Influence of metal nanoparticles synthesized by microorganisms upon soil-borne microscopic fungus Aspergillus terreus K-8 was studied. It was established that the metal nanoparticles synthesized by microorganisms affect the enzymatic activity of the studied culture. Silver nanoparticles lead to a decrease in cellulase activity and completely suppress the amylase activity of the fungus, while copper nanoparticles completely inhibit the activity of both the cellulase complex and amylase. The obtained results imply that the large-scale use of silver and copper nanoparticles may disrupt biological processes in the soil and cause change in the physiological and biochemical state of soil-borne microorganisms as well.
CdS and CdTe thin films were thermally deposited onto glass substrate. The CdCl2 layer was deposited onto CdS surface. These followed by annealing for different duration times to modify the surface and interface of the junction. The diffraction patterns showed that the intensity of the peaks increased with the CdCl2/annealed treatment, and the grain sizes are increased after CdCl2/annealed treatment