Static loads exposing to mechanical components can cause cracks, which are lead to form stress concentration regions causing the failure of structure. Generally, from 80% to 90% of structure failure is due to initiation of the cracks. Therefore, it is necessary to repair the crack and reduce its effect on the structure where the effect of the crack is modelled as an additional flexibility to the structure. In the last few years, piezoelectric materials have been considered as one of the most favourable repairing techniques. The piezoelectric material converts the applied voltage on it to a bending moment to counter the bending moment caused by the external load on the beam at the crack location. In this study, the design of the piezoelectric materials used to repair effect of crack on the mechanical behaviour of beam subjected to static loads is analytically achieved. This design includes calculating of desired dimensions of the material with the required voltage applied on it. The additional flexibility is expressed in term of a proposed unitless factor which can be calculated depend on experimental work. The results show that increasing the patch thickness increases the beam resistance to crack and load effects, while increasing the length of the piezoelectric material reduces the magnitude of the voltage required to repair the cracked beam.
Lead toxicity elicits neurological damage which is a well-known disorder that has been considered to be a major cause for multiple condition such as behavioral defect; mental retardation; and nerve insufficient activity.
This research is designed to estimate potential protective effect of vinpocetine on neurotoxicity stimulated by lead acetate in rats.
Eighteen adult rats of both sexes were randomly enrolled into three groups. Each group includes 6 rats as followings: Group I- Rats were given 0.3ml normal saline solution orally; then intraperitoneal injection of 100μl of the normal saline was given 1h later; this group was considered as control. Group II- Rats were given an intraperitoneal injection of 20mg/kg lead acetate
... Show MoreBackground: Ischemic heart disease is a major cause of the diastolic heart failure. Risk of heart failures was increased with microvascular coronary disease, which is characterized by left ventricular stiffness with impaired relaxation and reduced compliance. Aim of this study is to estimate the effect of the severity of myocardium ischemia on the left ventricle ejection fraction and left ventricular volume using SPECT with 99mTc MIBI and to compare the results with the echocardiography. The study included 117 subjects with ischemic heart disease were examined using SPECT and echocardiography techniques. The following
... Show MoreMeasurements of excess molar volumes VE , viscosities η , excess viscosities Δ ln η and excess molar activation energies of viscous flow ΔGE , are reported for binary mixtures of dimethylformamide (DMF) with , benzene , o-xylene , 1,4- dioxane and tetrahydrofuran are reported from density and viscosity measurements at 298.15 k and at atmospheric pressure over the entire composition range . The excess values are positive for the mixture (DMF+ polar solvent) and negative deviation from ideality for the mixture (DMF + non-polar solvent) over the whole composition range and discussed in the light of molecular interaction in the mixture.
The percentage of fatty acids, quantity of tocopherols, tocotrienols, carotens and physiochemical characteristics of crude red palm oil have been evaluated, in addition to specific chemical detection of active compounds unsaponifiable matters. Results of Gas Liquid Chromatography showed:- The major fatty acids in red palm oil is palmitic (44.36%) then oleic (39.65%), linolenic (10.55%), stearic (3.56%), myristic (1.22%), arachdonic (0.24%) and palmotic (0.19%). Red palm oil contains ? – ?- ?- ? – Tocopherols with concentration 258 , 121 , 259, 109 m/kg oil , ? – ?- ?- ? – Tocotrienol with concentration 462.77 , 571.03, 619.18, 509.07 m/kg oil respectively. Total tocopherols & tocotrienols 2909.05 m/kg oil and
... Show MoreThis research seeks to unravel the components of the argumentative discourse in the Book ofʻRawdat al-MuhebbeenwaNozhatt al-Mushtaqeenʼ - The Garden of Lovers and the Promenade of Longing People – by Ibn Al-Qayyem Al-Jawziyah. This is because this book has a moderate discourse with a sound Islamic thought that is characterized by its sustainability, popularity, realism, and interaction with the successive developments of the new age. This reflects the intellectual maturity the composing process has reached in the philosophy of love and its educational bases in every place and time. To explore the componets, properties, and the working mechanisms of an argumentative discourse in Ibn Qayyem’s book, the present work has been conducted
... Show MoreArgumentation is not a contemporary, yet a deep rooted intellectual phenomenon dates back to Romans and Greeks times. The argumentative elements ,the author is trying to convey to the reader, are linguistic procedures aim at persuading and being persuaded of what is true. The present study traces, through Camus’ novel The plague, the best method to construct argumentative techniques used to express the author’s deep philosophies.
Résumé
L’argumentation n’est pas un phénomène intellectuel nouveau, ses origines reviennent aux savants grecs et romains. Elle est une act
... Show MoreA mathematical model constructed to study the combined effects of the concentration and the thermodiffusion on the nanoparticles of a Jeffrey fluid with a magnetic field effect the process of containing waves in a three-dimensional rectangular porous medium canal. Using the HPM to solve the nonlinear and coupled partial differential equations. Numerical results were obtained for temperature distribution, nanoparticles concentration, velocity, pressure rise, pressure gradient, friction force and stream function. Through the graphs, it was found that the velocity of fluid rises with the increase of a mean rate of volume flow and a magnetic parameter, while the velocity goes down with the increasing a Darcy number and lateral walls. Also, t
... Show MoreBackground: The long term survival of dental implants is evaluated by the amount of crestal bone loss around the implants. Some initial loss of bone around dental implants is generally expected. There is reason to believe that reflecting a mucoperiosteal flap promotes crestal bone loss in the initial phase after an implant has been inserted. The surgical placement of a dental implant fixture is constantly changing and in recent years, there has been some interest in developing techniques that minimize the invasive nature of the procedure, with flapless implant surgery being advocated. The purpose of this study was to compare the radiographic level of the peri- implant bone after implant placement between traditional flapped surgery and f
... Show MoreThe present study was carried to evaluate antibacterial activity of Acetone, Alcholic (cold and hot) and Aqueaus(water) extracts of Citrus aurantifoliaseeds,against growth of some bacteria isolated from burns infections(Pseudomonas aeruginosa,Escherichia coli, Klebsiellapneumonia,Staphylococcusaureus)fromKindy HospitalIn Baghdad from March to June 2012.Antibiotic Sensitivity was done for all isolated bacteria used in this study.Results showed variation in antibacterial activity of different extracts against all tested bacteria by well diffusion technique in agar and measuring the diameter of inhibition zone, at concentration 250Mg-ml. Acetone extract had the greatest inhibitory effect followed by hot alcoholci extract, and then cold alcohol
... Show MoreThe study involved preparing a new compound by combining between 2-hydroxybenzaldehyde and (Z)-3-hydrazineylideneindolin-2-one resulting in Schiff bases and metal ions: Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) forming stable minerals-based-Schiff complexes. The formation of resulting Schiff bases is detected spectrally using LC-Mss which gave corresponding results with theoretical results, 1H-NMR proves the founding of N=CH signal, FT-IR indicates the occurrence of imine band and UV-VIs mean is proved the ligand formation. On the other hand, minerals-based-Schiff was characterized using the same spectral means that relied with ligand (Schiff bases). Those means gave satisfactory results and proved the suggested distinguishable geometries.
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