This piece of research work aims to study one of the most difficult reaction and determination due to continuous and rapid variation of reaction products and the reactants. As molybdenum (VI) aid in the decomposition of hydrogen peroxide in alkaline medium of ammomia, thus means a continuous liberation of oxygen which cuases and in a continuous manner a distraction in the measurement process. On this basis pyrogallol was used to absorbe all liberated oxygen and the result is an a clean undisturbed signals. Molybdenum (VI) was determined in the range of 4-100 ?g.ml-1 with percentage linearity of 99.8% or (4-300 ?g.ml-1 with 94.4%) while L.O.D. was 3.5 ?g.ml-1. Interferring ions (cations and anions) were studied and their main effect was reduced using mini column cataining resin, or the separation of molybdenum via its precipitation prior to injection. The reaction system and manifold were used to determine pyrogallol (4-40 ?g.ml-1, L.O.D. 80 ?M) and hydrogen peroxide (0.1-5M, L.O.D. 50 mM). Relative standard diviation was better the 1%.
Realistic implementation of nanofluids in subsurface projects including carbon geosequestration and enhanced oil recovery requires full understanding of nanoparticles (NPs) adsorption behaviour in the porous media. The physicochemical interactions between NPs and between the NP and the porous media grain surface control the adsorption behavior of NPs. This study investigates the reversible and irreversible adsorption of silica NPs onto oil-wet and water-wet carbonate surfaces at reservoir conditions. Each carbonate sample was treated with different concentrations of silica nanofluid to investigate NP adsorption in terms of nanoparticles initial size and hydrophobicity at different temperatures, and pressures. Aggregation behaviour and the
... Show MoreThe temperature control process of electric heating furnace (EHF) systems is a quite difficult and changeable task owing to non-linearity, time delay, time-varying parameters, and the harsh environment of the furnace. In this paper, a robust temperature control scheme for an EHF system is developed using an adaptive active disturbance rejection control (AADRC) technique with a continuous sliding-mode based component. First, a comprehensive dynamic model is established by using convection laws, in which the EHF systems can be characterized as an uncertain second order system. Second, an adaptive extended state observer (AESO) is utilized to estimate the states of the EHF system and total disturbances, in which the observer gains are updated
... Show MoreThis study aims to fabricate and assess the β-tricalcium phosphate (β-TCP) bioactive ceramic coat layer on bioinert ceramic zirconia implants through the direct laser melting technique by applying a long-pulsed Nd:YAG laser of 1064 nm. Surface morphologies, adherence, and structural change in the coatings were evaluated by optical microscopy, field emission scanning electron microscope, hardness, and x-ray diffractometer. The elastic modulus (EM) of the coating was also determined using the nanoindentation test. The quality of the coating was improved when the laser power was 90 W with a decrease in the scan speed to 4 mm s−1. The chemical composition of the coat was maintained after laser processing; also, the Energy Dispersive
... Show MoreThis study was conducted for the purpose of exploring the relationship between positive thinking and academic achievement in art history. And it relates to the student’s personality, intelligence, abilities and economic and social level. The sample of the study consisted of (40) male and female students from the first stage students - Department of Art Education in the Faculty of Fine Arts / Morning Study, A positive thinking questionnaire was applied to them, and the study found that there is no positive relationship between positive thinking and academic achievement in art history.
The research falls in to three sections: the first section has two parts; the first one includes a general description of the research: its problem, aim, limitations, methodology, and the terminological definition. The second part presents historical background of the weekly school speeches in Iraq and their types. Section Two has two parts: the first is about the principles of writing weekly speeches, their elements, and principals, their conditions. As for the second part, it is about introducing four samples of weekly school speeches distributed as two taken from Al-karkh sector and two taken from Al-rusafa'a sector. The third section: analyzing the content of the sample and giving a short historical background abo
... Show MoreThe problem with the research essential questionably is: (What are the variations phenotypic designs decorative Alangat) The research aims detection of phenotypic variables and Acgalah in Wares structure decorative employee in the decorative designs in the external and internal interfaces to the tombs of the Iraqi holy shrines and the walls of b (upper threshold _ Najaf) Alattabatin Husseinia and Abbasid in the holy city of Karbala) current position (1435 AH / 2014 AD). And ensure that the theoretical framework topics following: diversity in the structure motifs and vegetable processors color as well as landmarks decking decorative decorative gift items and adopted a researcher at the procedures purely on the descriptive analytical appro
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