A new concrete rheometer is introduced including its innovation, actual design, working rules,
calibration, and reliability. A modified design of Tattersall two-point device is created. Some of
components are purchased from local and foreign markets, while other components and the
manufacturing process are locally fabricated. The matching viscosity method of determining the mixer
viscometer constants is demonstrated and followed to relate torque and rotational speed to yield stress
and viscosity (Bingham parameters). The calibration procedures and its calculation are explained.
Water is used as a Newtonian fluid, while; cement paste (cement + water) with w/c ratio equal to
(0.442) is used as a non-Newtonian fluid. The cement paste is tested in “Petroleum Research and
Development Center” by “OFITE Model 800 Viscometer”. In order to verify the reliability of the new
rheometer, an Artificial Neural Network (ANN) model with a well selected bank of data is constructed;
and (16) Mixes of Self Compacting Concrete (SCC) are constructed, mixed and tested by the new
Rheometer. The results from model (predicted) and those from the experimental work (measured) were
found to have very good degrees of correlation and matching, which indicates that the new rheometer
can be reliable.
Background: Prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; such methods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasive action. This study was done to assess the effect of three polishing systems on surface texture of new anterior composites after storage in artificial saliva. Materials and methods: A total of 40 Giomer and Tetric®N-Ceram composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for one month and then samples were divided into four groups according to surface treatment: Group A (control group):10 specimens received no surfa
... Show MoreThe investigation of natural convection in an annular space between two concentric cylinders partially filled with metal foam is introduced numerically. The metal foam is inserted with a new suggested design that includes the distribution of metal foam in the annular space, not only in the redial direction, but also with the angular direction. Temperatures of inner and outer cylinders are maintained at constant value in which inner cylinder temperature is higher than the outer one. Naiver Stokes equation with Boussinesq approximation is used for fluid regime while Brinkman-Forchheimer Darcy model used for metal foam. In addition, the local thermal equilibrium condition in the energy e
A theoretical and protection study was conducted of the corrosion behavior of carbon steel surface with different concentrations of the derivative (Quinolin-2-one), namly (1-Amino-4,7-dimethyl-6-nitro-1H-quinolin-2-one (ADNQ2O)). Theoretically, Density Functional Theory (DFT) of B3LYP/ 6-311++G (2d, 2p) level was used to calculate the optimized geometry, physical properties and chemical inhibition parameters, with the local reactivity to predict both the reactive centers and to locate the possible sites of nucleophilic and electrophilic attacks, in vacuum, and in two solvents (DMSO and H2O), all at the equilibrium geometry. Experimentally, the inhibition efficiencies (%IE) in the saline solution (of 3.5%) NaCl were studied using potentiomet
... Show MoreNew nitrone and selenonitrone compounds were synthesized. The condensation method between N-(2-hydroxyethyl) hydroxylamine and substituted carbonyl compounds such as [benzil, 4, 4́-dichlorobenzil and 2,2́ -dinitrobenzil] afforded a variety of new nitrone compounds while the condensation between N-benzylhydroxylamine and substituted selenocarbonyl compounds such as [di(4-fluorobenzoyl) diselenide and (4-chlorobenzoyl selenonitrile] obtained selenonitrone compounds. The condensation of N-4-chlorophenylhydroxylamine with dibenzoyl diselenide obtained another type of selenonitrone compounds. The structures of the synthesized compounds were assigned based on spectroscopic data (FT-IR,
... Show MoreThe aldol condensation of 2-acetylnaphthalene with 9-anthracene carboxaldehyde afforded α, β-unsaturated keton (1) . New heterocyclic compounds containing: cyclohexenone[2], indazole[3], pyrimidinethion [4], thiazolo fused pyrimidine[5], isoxazoline[6], substituted pyrazoline[7]a-d and pyrimidinone[8] rings system were synthesized from α, β-unsaturated keton[1]. Cyclization of [1] with ethylacetoacetate gave the mentioned heterocycle cyclohexanone [2]. The cyclo condensation of [2] with hydrazine gave the new indazole derivative [3]. furthermore, the reation of [1]with thiourea gives thiopyrmidine derivative [4]. The cyclo condensation of [4] with chloroacetic acid gave the fused rings [5]. Then reacted compound[1] with hydroxy
... Show MoreThe purpose of my thesis is to prepare four new ligands (L1-L4) that have been used to prepare a series of metal complexes by reacting them with metal ions: M=(Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) Where succinyl chloride was used as a raw material for the preparation of bi-dented ligands (L1-L4) by reacting it with potassium thiocyanate as a first step and then reacting with (2-aminobenzothiazole, Benzylamine, 4-aminoantipyrine, Sulfamethoxazole) respectively as a second step with the use of dry acetone as a solvent, the chemical formula of the four ligands prepared in succession: N1,N4-bis(benzo[d]thiazol-2-ylcarbamothioyl)succinamide (L1) N1,N4-bis(benzylcarbamothioyl)succinami
... Show MoreSynthesis of a new class of Schiff-base ligand with a tetrazole moiety to form polymeric metal complexes with CoII, NiII, ZnII, and CdII ions has been demonstrated. The ligand was synthesised by a multi-steps by treating 5-amino-2-chlorobenzonitrile and cyclohexane -1,3-dione, the 5,5'-(((1E,3E)-cyclohexane-1,3-diylidene)bis(azanylylidene))bis(2-chlorobenzonitrile) was obtained. The precursor (M) was prepared from the reaction 5,5'-(((1E,3E)-cyclohexane-1,3-diylidene)bis(azanylylidene))bis(2-chlorobenzonitrile) with NaN3 to obtained (1E,3E)-N1,N3-bis(4-chloro-3-(1H-tetrazol-5-yl)phenyl)cyclohexane-1,3-diimine (N). By reacting the precursor (M) with CS2
... Show MoreSynthesis of 2-(4-Acetyl-phenyl)-4-nitro-isoindole-1, 3-dione chalcones were performed by fusion of 3-nitro phthalic anhydride with p-aminoacetophenone. Then the later was grinded with different aromatic aldehydes in the presence of sodium hydroxide to produce new chalcones derivatives A3-10 without using any solvent formation of new N- arylphthailimide chalcones were confirmed by FT-IR,1HNMR, 13CNMR spectroscopy and all final compounds were tested for their antifungal and antibacterial activity some of them showed more biological activity than the standard drugs