Piezoelectric structures are nowadays used in many different applications. A better understanding of the influence of material properties and geometrical design on the performance of these structures helps to develop piezoelectric structures specifically designed for their application. Different equivalent circuits have been introduced in the literature to investigate the behaviour of piezoelectric transducers. The model parameters are usually determined from measurements covering the characteristic frequencies of the piezoelectric transducer. This article introduces an analytical technique for calculating the mechanical and electrical equivalent system parameters and characteristic frequencies based on material properties and geometry for a cantilever bimorph structure. The model is validated by measurements using a cantilever bimorph and fits the experimental results better than previous models. The model gives a full set of piezoelectric transducer parameters and is therefore well suited for further theoretical investigations of piezoelectric transducers for different applications. The results also show that even small manufacturing tolerances have a considerable effect on the system parameters and characteristic frequencies. This might lead to intolerable deviations, especially in dynamic applications and should be avoided by careful design and production.
Background:
Bronchiolitis is the first episode of wheezing associated with low-grade fever, rhinitis, tachypnea, and increase respiratory effort in a previously healthy infant during the winter
months. It is the most common disease of the lower respiratory tract.
Methods:
This is a case control study carried out on one hundred infants with a mean age of 3.9 months ± 2.2 months admitted to Children Welfare Teaching Hospital in Medical City –
Baghdad with acute bronchiolitis during the period from 1st January 2006 to 1st April 2006. epidemiological risk factors, clinical presentations, chest X-ray findings, treatment,
complications and outcome were analyzed. Another one hundred infants (age and sex
The wall of the esophagus in Mabuya aurata septemaeniata as in high vertebrates consists of four layers, mucosa, submucosa,muscularis and serosa. Mucosa forms many unorganized short and long folds penetrate inside the esophageal cavity. Mucosa contains two sub layers, first one is lining epithelium which includes two types of cells, simple ciliated columnar epithelial cells and goblet cells, second one is lamina properia. Mucosa does not have muscularis mucosa. There is no esophageal glands within esophagus. Many special stains were used as (Periodic Acid Schiff (PAS)) to detect Carbohydrates in goblet cells. Alcian blue were used to detect the amount of goblet cells within lining epithelium. Alcian blue + PAS together confirm that the
... Show MoreMultiple sclerosis (MS) is one of an autoimmune condition with uncertain etiopathology. According to new data, ABO system had played a role in the development and understanding numerous diseases. Lower level of 25-hydroxy vitamin D3 (25-OHD3) is considered as a risk factor for MS. The aims of this study is to identify the role of blood group distribution on the levels of parathyroid hormone (PTH), 25-OHD3, total calcium, inorganic phosphorus and total magnesium on MS patients. Additionally, we assessed the relation between Expanded Disability Status Scale (EDSS) and study parameters in patients. The Study included 107 patients with MS were distributed in to four groups according to their blood group (A, B, AB, and O). Additi
... Show MoreAbstract:
Background: The most frequent movement issue seen in clinical practice is tremors. It is known as repetitive, involuntary oscillations. The diagnostic process for tremor patients can be time-consuming and complicated, as the identification of “Essential Tremor” and its distinction from other types of tremor.
Objectives: This study aimed to describe the electrophysiological findings of essential, enhanced physiological, and physiological tremors, using surface electromyography and an accelerometer.
Patients and Methods: The study included 24 patients with essential tremors, 10 patients with enhanced physiological tremors, and 10 patient
... Show MoreOn the basis of the results which was previously obtained from the structural and the theoretical studies on ~-adrenergic drugs, a series of 2-propanolamine derivatives containing triazole moiety have been prepared and evaluated for their cardiovascular activity . These derivatives were tested by using spontaneously-beating right atria of albino rats.
Background: - Carcinoma of the lung has became the most common type of cancer since 1985 & the most common cause of cancer death in both males & females.
Aim of study: - To assess the diagnostic accuracy of bronchial wash cytology & application of immunocytochemical methods, using two tumor markers (low molecular weight cytokeratin & epithelial membrane antigen) for more accurate & precise diagnosis of lung tumors.
Patients, materials and methods: - Fifty fifes suspected lung cancer cases according to their clinicoradiological examinations were included in this study.
Bronchial wash cytology was performed for all the 55 patients. Smears were stained by conventional cytological stain i
Abstract
The hydrometallurgical method was used to platinum and palladium leaching with aqua regia solution (3HCl: HNO3). The leaching experiments were designed to obtain the optimum conditions by using Taguchi method with 16 experiments at three different factors (time, temperature and solid to liquid ratio), and each factor has four different levels. In this study, leaching the powder sample of catalytic converter that contains platinum and palladium was conducted on the basis of the formation of chloro complexes platinum and palladium (PtCl62-, PdCl42-) with different concentrations in the acidic solution. The optimum condi
... Show MoreThis paper deals with the most important factors leading to child marriage and the importance of the study shed light on the factors leading to the marriage of minors than to underage marriage of repercussions on society and on the individual and household level, and thus its effects on the development of Almrah Battabarha half of society Vsba minors hinders progress Almrah and deprive of her childhood and deprive them of education leading to the spread of illiteracy , in addition to the marriage of minors having psychological risks, health and social girl and the family together.
The objectives of the study focused on identifying the socio and cultural factors leading to the marriage of minors, and highlights the marriage Alqaasratal
The budget in general is a plan of action prepared by the government and works to submit it to the legislative authority for the purpose of approval, and translates its economic and social policy into annual digital targets. In order to know the effectiveness of the public budget, it must be linked to other financial planning tools such as foreign exchange policy and credit policy and measured by the economic and social results and not only financial results.
And to avoid the shortcomings that accompanied the budget because of the use of the traditional method of balancing items and finding remedies to get out of the financial crises experienced by countries in general and Iraq in particular in the
... Show MoreThis research deals with a unique and innovative topic, that is the study of complaint in the Quranic text. Despite its importance, it has never been studied before, because most of the complaint 's meanings in the Quranic text is: the in explicit complaint. The mentioned complaint's expressions in different contexts overlap with other purposes, in particular call method and its peripherals like mourn , ask for help , exclamation and others.
Moreover, expressions that reveal complaint are related to the complainant's emotional and psychological status, and the complaint's context.
This research deals with the topic into two sections: The first deals with the important expression of complaint such as: iff, ouah, mooing, crying. The