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.
a simple accurate and sensitive spectrophotometric method for the determination of promethazine HCI has been developed the method is based on the oxidative coupling reaction of promethazine
A new spectrophotometric flow injection method has been establish for the determintaions of some catecholaminedrugs
A simple, rapid and sensitive spectrophotometirc method for the determination of trace amounts of promethazine hydrochloride in the aqueous solution is described. The method is based on the complexation of promethazine hydrochloride with In (III) in the presence of sodium hydroxide to form an soluble product with maximum absorption at 304nm. Beer’s law is obeyed over the concentration range of (2- 20μg/ml) with molar absorptivity of (1.92× 103 L.mol-1 .cm -1 ). The optimum conditions for all development are described and the proposed method has been successfully applied for the determination of promethazine hydrochloride in bulk drug.
This paper discusses the method for determining the permeability values of Tertiary Reservoir in Ajeel field (Jeribe, dhiban, Euphrates) units and this study is very important to determine the permeability values that it is needed to detect the economic value of oil in Tertiary Formation. This study based on core data from nine wells and log data from twelve wells. The wells are AJ-1, AJ-4, AJ-6, AJ-7, AJ-10, AJ-12, AJ-13, AJ-14, AJ-15, AJ-22, AJ-25, and AJ-54, but we have chosen three wells (AJ4, AJ6, and AJ10) to study in this paper. Three methods are used for this work and this study indicates that one of the best way of obtaining permeability is the Neural network method because the values of permeability obtained be
... Show MoreThe nay is one of the important in stvument in Arabic music which is considered one of the oriental instruments used in the oriental music tect, and is also considered one of the basic instruments in Arabic music, It is used in many religious and mundane areas, through its expressive capabilities through which expression and conveyance of feelings to the recipient, despite their importance and role in music, and through the researcher's follow-up to this subject did not find a study on the potential capabilities of the machine. In view of the above, and given the importance of this subject at the researcher, the need arose for research to study (the potential of the flute machine)..
The research involved a rapid, automated and highly accurate developed CFIA/MZ technique for estimation of phenylephrine hydrochloride (PHE) in pure, dosage forms and biological sample. This method is based on oxidative coupling reaction of 2,4-dinitrophenylhydrazine (DNPH) with PHE in existence of sodium periodate as oxidizing agent in alkaline medium to form a red colored product at ʎmax )520 nm (. A flow rate of 4.3 mL.min-1 using distilled water as a carrier, the method of FIA proved to be as a sensitive and economic analytical tool for estimation of PHE.
Within the concentration range of 5-300 μg.mL-1, a calibration curve was rectilinear, where the detection limit was 3.252 μg.mL
The aim of this study is to investigate the main causes of the family violence and its
social effects.
The study reveals that main factors causes of the violence are interaction between
multi-factors.
The study shows that the poverty, low educational level, house crowded, large family
size, all of these variables causes of the violence, and then causes of family disorganization
and juvenile delinquency.
The study contain of three sections:
First: Focused on the causes of the violence.
Second: The interaction between multi factors.
Third: Social effects of family violence.
Flow-injection (FI) spectrophotometric method has been developed for the analysis of thymol in pharmaceutical preparations. The method is based on organic coupling reaction between thymol and 4-amino antipyrine in the presence of alkaline medium to form an intense stable red color complex with copper nitrate that has a maximum absorption at 490 nm. Optimum conditions for determination of the drug was investigated .The calibration graph was linear over the range of 5-500 µg.ml-1 of thymol . The limit of detection (LOD) and limit of quantification (LOQ) were 1.81 ?g mL-1 and 3.60 ?g mL-1 respectively .The proposed method was applied satisfactorily to the determination of thymol in mouth wash preparations. The procedure is characterized by
... Show More
