With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil’s mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning the progress of implanted device research in the future. This review will hopefully lead to increasing efforts towards the development of low powered, highly efficient, high data rate and reliable automatic frequency controllers for implanted devices.
In this work, chemical oxidation was used to polymerize conjugated polymer "Polypyrrole" at room temperature Graphene nanoparticles were added by in situ-polymerization to get (PPY-GN) nano. Optical and Electrical properties were studied for the nanocomposites. optical properties of the nanocomposites were studied by UV-Vis spectroscopy at wavelength range (200 -800 nm). The result showed optical absorption spectra were normally determined and the result showed that the maximum absorbance wave length at 280nm and 590nm. The optical energy gap has been evaluated by direct transition and the value has decreased from (2.1 eV for pure PPy) to (1.3 eV for 5 %wt. of GN). The optical constants such as the band tail width ΔE was evaluated, the
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The research aims to identify tax exemptions, their objectives and types, as well as to shed light on the concept of sustainable development, its objectives, dimensions and indicators (economic, social and environmental), as well as to analyze the relationship between tax exemptions and economic development, in addition to measuring and analyzing the impact of tax exemptions on economic development in Iraq for the period ( 2015 - 2021) using the NARDL model. The research problem centers on the fact that failure to employ financial policy tools correctly led to a weakness in achieving economic justice, which leads to a failure to improve social welfar
... Show MoreProblem of research as defined, including the following:what is impact organizing of configuration for still life in paintings of students in the Department of Art Education in subject of colors ?Study of well training for organized in painting of still life is necessary for a teacher of art education to contribute effectively to the performance of his letter, so is this research in response to the public goals for a subject of art education. The current research aims to:1. Impact organization of configuration for still life in paintings of students in the Department of Art Education for the first grade in subject of colors2. Role organization of configuration for still life in the painting to serve the educational process in subject of
... Show MoreThe study aimed to : - To determine whether there are significant differences between Fartlek training and the increase in the molecular biology (VEGF - basal fibroblast growth factor) for arena and field players in an (800m) youth event. - Determine whether there are statistically significant differences between Fartlek training and the increase in molecular biology and some physical variables for the players (800m) in the arena and field for youth. - Determine whether the Fartlek training method is the most appropriate to achieve statistically significant differences in the research variables for the players (800m) in the arena and field for youth. The researchers used the experimental method for its suitability and the nature of the rese
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Personality is one of the most important elements that should be developed in university student. Thus, we have to develop the positive traits and neutralize the negative traits of students as well as we have to pay attention to the level of student achievement at the same time, the researcher designed a scale to measure the traits of study sample. The research come out with a number of recommendations and proposals, the most important of which Enhancing the positive characteristics of university students in order to reach them to the level of mature personality with mental health. Enhancing the positive role of the high level of achievement by motivating the stude
... Show MoreThe insurance activity in the various countries of the world are important indicators of the strength of the country's economy, he came to study the stages compensation insurance settlement against fire and the importance of investing time risk in achieving the payment of compensation speed, and the implications for the continuation of the insured to carry out insurance with the insurance company, whether working within the public sector or the private sector. Hence the research problem in how quickly insurance companies to pay compensation as soon as possible and the return of the insured to carry out its work and make up for what he died from loss. Intentional sample was selected from branches and divisions and Their assistants manager
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The internal control is the tool through which it is possible to verify and ensure the implementation of tasks in accordance with the established plans and programs and to evaluate the level of performance that is implemented within the different companies.
A guarantee from the supplier with the absence of a specialized technical committee that follows up the stages of implementing the contract and disbursing all amounts of financial dues to the supplier before completing the implementation of the contract and overlooking the non-implementation of some clauses of the contract by the committee in charge of
... Show MoreThe research aims to apply one of the techniques of management accounting, which is the Quality Function Deployment(QFD) on the Pepsi product in Baghdad Soft Drinks Company and to determine the technical requirements objectively that have been applied in practice in Baghdad Soft Drinks Company / a private shareholding company, as it focuses on meeting the quality requirements and achieving positive quality to provide a product It meets the requirements of current and future customers, hence the importance of research that indicates that the Quality Function Deployment(QFD) is a useful tool to develop the requirements of new products, being a design process driven by customers through their voices, and thus contribute to achieve a competi
... Show MoreThe quantitative determination of the estrogen E2, Progestron P4 & follicle stimulating hormones FSH in the serums of Albino mice used in the experiments & treated by crude alcoholic extracted 95% of the seeds & leaves of Apium graveolens was a significant increase in the concentration of estrogen of different kinds of the extracted in comparison with the values of the coefficient of the control group, that is the study recorded a significant increase of the concentration of estrogen; it was the highest in the mice which was administrated by the methanolic extracted 95%, then it was less in the mouse which was administrated by the ethanolic extracted., and it was the least in the mice which were administrated by the crude ethanolic-methano
... Show MoreTheresearch took the spatial autoregressive model: SAR and spatial error model: SEM in an attempt to provide a practical evident that proves the importance of spatial analysis, with a particular focus on the importance of using regression models spatial andthat includes all of them spatial dependence, which we can test its presence or not by using Moran test. While ignoring this dependency may lead to the loss of important information about the phenomenon under research is reflected in the end on the strength of the statistical estimation power, as these models are the link between the usual regression models with time-series models. Spatial analysis had
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