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.
During the syrvey on natural enemies of whiteflies in Iraq, the following. predators were recorded.
Road traffic accidents (RTAs) are events that suddenly, inadvertently and unexpectedly occur under unforeseen circumstances that involve at least one moving vehicle and result in one or more road users being killed or injured. Unfortunately, Iraqi governorates suffer from higher rates of traffic accident casualties compared with the rates of casualties from terrorist attacks; this situation reveals a serious and growing problem. Road traffic accidents are not easy to eradicate. However, their prevalence can be reduced to the barest minimum via periodic assessments of traffic accident characteristics and the most important aspects for road authorities to consider when designing and evaluating the performance of a road to improve traf
... Show MoreBackground: Melatonin is the main hormone secreted by the pineal gland. This indole compound (N-acetyl-5-methoxytryptamine) is derived from serotonin after two biochemical steps. Melatonin has been implicated in some pharmacological effects including sedative/hypnotic, anticonvulsant activity and others. The aim of this study was to investigate the antinociceptive effect of different doses of melatonin administered i.p. to mice, and then, to find the dose- response line of melatonin in mice as analgesic agent.
Methods: The dose response effect of melatonin (10, 50, and 100mg/kg) were assessed against control using tail flick test in mice as a model of nociceptive pain. In this model, all doses of melatonin were given intraperitoneally
The effect of annealing temperature (Ta) on the electrical properties like ,D.C electrical conductivity (σ DC), activation energy (Ea),A.C conductivity σa.c ,real and imaginary (ε1,ε2) of dielectric constants ,relaxation time (τ) has been measured of ZnS thin films (350 nm) in thickness which were prepared at room temperature (R.T) using thermal evaporation under vacuum . The results showed that σD.C increases while the activation energy values(Ea) decreases with increasing of annealing temperature.(Ta) from 303- 423 K .
The density of charge carriers (nH) and Hall mobility (μH) increases also with increasing of annealing temperature Hall effect measurements showed that ZnS films were n-type converted to p-type at high annealin
Back ground : Fever is a common medical problem in
children. parents have been shown unrealistic fears of
harmful effects of fever in their children. Resulting in
inappropriate management of fever in their children.
Objective: the objective of this study was to survey
parents about their knowledge andattitude concerning fever
in their children.
Methods : The study involved random selection of
parents who brought their febrile children to emergency
department or out-patient clinics of five teaching and non
teaching hospitals in Baghdad from first of October to end
of December 2002.
Parents of 400 febrile children were interviewed using a
standard questionnaire to obtain sociodemographic
informatio
The concept of the order sum graph associated with a finite group based on the order of the group and order of group elements is introduced. Some of the properties and characteristics such as size, chromatic number, domination number, diameter, circumference, independence number, clique number, vertex connectivity, spectra, and Laplacian spectra of the order sum graph are determined. Characterizations of the order sum graph to be complete, perfect, etc. are also obtained.
This paper exclusively deals with medical encounters. . Structurally and thematically, it manifests itself in five parts. The First part deals with medical encounters as well as essential speech activities which cover (a) frames (certain types of talk) (b) the patient’s account and the patient’s story or more precisely the patient telling his story and (c) the act of questioning the patient. The Second part revolves round genre and register. The former, in most cases, suggests that the format of medical encounters is conversational. With register; we have a converse reality that restrictively tries to narrow things and give them a certain flavor. The Third part realizes the technicalities of medical encounters (a) the setting of an inte
... Show MoreThe concept of bipolar fuzzy ideals in a TM-algebra was introduced and some properties of these ideals are investigated. Also, a few relations between a bipolar fuzzy ideal and T-ideal are discussed. A new bipolar fuzzy set with a homomorphism of TM-algebra is defined. The Cartesian product of bipolar fuzzy T-ideals in Cartesian product TM-algebras is given.