The research involved attempt to inhibit the corrosion of Al-Si-Cu alloy in 2.5x10-3 mol.dm-3 NaOH solution (pH=11.4) by addition of six different inhibitors with three concentrations (1x10-3, 1x10-2, and 0.1 mol.dm-3). These inhibitors include three organic materials (sodium acetate, sodium benzoate, and sodium oxalate) and three inorganic materials (sodium chromate, disodium phosphate, and sodium sulphate). The data that concerning polarization behaviour are calculates which include the corrosion potential (Ecorr) and current density (icorr), cathodic and anodic Tafel slopes (bc & ba), and polarization resistance (Rp). Protection efficiency (P%) and activation energy (Ea) values were calculated for inhibition by the six inhibitors. The results indicated the effect of temperature on the inhibition in basic media.
Background: Considering the antioxidant, anti-inflammatory, and antimicrobial properties of green tea, this study aimed to evaluate the histopathological effect of the sulcular irrigation of green tea extract in the treatment of experimental gingivitis in rabbit.
Materials and methods: For this experimental study, 45 male rabbits, separated in two groups, control non- irrigated group (5rabbits) and study group (40 rabbits), gingivitis induced by ligatures was packed subgingivally in the lower right central incisors of the experimental group for seven days. Then, the animals were randomly designated to two irrigated groups (20 rabbits
... Show MoreSynthesis of 2-mercaptobenzothiazole (A1) is performed from the reaction of o-aminothiophenol and carbon disulfide CS2 in ethanol under basic condition. Compound (A1) is reacted with chloro acetyl chloride to give compound (A2). Hydrazide acid compound (A3) is obtained from the reaction of compound (A2) with hydrazine hydrate in ethanol under reflux in the presence of glacial acetic acid .The reaction of hydrazide acid compound (A3) with ethyl acetoacetate gives pyrazole compound (A4). The new hydrazone compound (A5) was prepared from the reaction of compound (A3) with benzaldehyde. Reaction of compound
... Show MoreUpper limb amputation is a condition that severely limits the amputee’s movement. Patients who have lost the use of one or more of their upper extremities have difficulty performing activities of daily living. To help improve the control of upper limb prosthesis with pattern recognition, non-invasive approaches (EEG and EMG signals) is proposed in this paper and are integrated with machine learning techniques to recognize the upper-limb motions of subjects. EMG and EEG signals are combined, and five features are utilized to classify seven hand movements such as (wrist flexion (WF), outward part of the wrist (WE), hand open (HO), hand close (HC), pronation (PRO), supination (SUP), and rest (RST)). Experiments demonstrate that usin
... 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 MoreNew, simple and sensitive batch and Flow-injecton spectrophotometric methods for the determination of Thymol in pure form and in mouth wash preparations have been proposed in this study. These methods were based on a diazotization and coupling reaction between Thymol and diazotized procaine HCl in alkaline medium to form an intense orange-red water-soluble dye that is stable and has a maximum absorption at 474 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 0.4-4.8 and 4-80 µg.ml-1 of Thymol, with detection limits of 0.072 and 1.807 µg.ml-1 of Thymol for batch and FIA methods respectively. The FIA procedure sample throughput was 80 h-1. All different chemical and physical e
... Show MoreA novel demountable shear connector for precast steel-concrete composite bridges is presented. The connector uses high-strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents bolts from slipping within their holes. Moreover, the connector promotes accelerated construction and overcomes the typical construction tolerance issues of precast structures. Most importantly, the connector allows bridge disassembly. Therefore, it can address different bridge deterioration scenarios with minimum disturbance to traffic flow including the following: (1) precast deck panels can be rapidly uplifted and replaced; (2) connectors can be rapidly removed and replaced; and (
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