Abstract: Despite the distinct features of the continuous wave (CW) Terahertz (THz) emitter using photomixing technique, it suffers from the relatively low radiation output power. Therefore, one of effective ways to improve the photomixer emitter performance was using nanodimensions electrodes inside the optical active region of the device. Due to the nanodimension sizes and good electrical conductivity of silver nanowires (Ag-NWs), they have been exploited as THz emitter electrodes. The excited surface plasmon polariton waves (SPPs) on the surface of nanowire enhances the incident excitation signal. Therefore, the photomixer based Ag-NW compared to conventional one significantly exhibits higher THz output signal. In this work, the effect of Ag-NWs dimensions and number on the incident optical field is investigated by utilizing the Computer Simulation Technology (CST) Studio Suite. The simulation results show that increasing Ag-NWs length to SPP propagation length ratio plays a significant role on the incident field increment due to its effect on reducing the SPP propagation losses. The increment of Ag-NWs number and length in the nanoelectrodes based photomixer can contribute to increase the electric field in the active region by 1.5 times at the longer excitation wavelength (850 nm). As a result of this increment, the THz output power and the conversion efficiency are expected to be enhanced by a factor of five
The professional skepticism is one of the fundamental concepts necessary for practicing the audit profession, without which the auditor can not reach a reasonable assurance as to the correctness of the evidence and the information obtained by the auditing department. The auditor's possession of the characteristics of professional skepticism and his practice of professional skepticism during the audit process lead to an increase The quality of audit and thus raise the confidence of the financial community in the audit profession again after the exposure of several crises led to the loss of financial society confidence in the audit profession.
The aim of the study is to measure the impact of professional sk
... Show MoreTechnical education in Iraq Composed of, a complex system of technical competence and scientific, technical and administrative, which extends to cover large areas of the country and constitute a vicious circle between economic development, social and cultural rights through middle-management on the one hand, and between academic knowledge and political decision-making, which aims to bring such development On the other hand, in the light of that education is the actual technical extension applied to create the idea of complementarily between them. In Iraq, have been distributed institutes and technical colleges to achieve those goals, in addition to realizing the idea of integration between them and community, and integration of t
... Show MoreTarget costing is one of the modern techniques in strategic Management accounting, Is has shown active adoption to changes in current business environments, In addition, is has seen a growth in strategic approach, The goal of using target costing is to build and strengthen competition abilities of economic units through introducing appropriate ways to decrease cost values while maintaining and improving quality of product, So this study is aim to show how can economic units use target costing to achieve competitive advantages .
The objective of the research is to measure the impact of social responsibility on the financial performance of the National Bank of Iraq for the period from 2014 to 2016 (3 years) through discussing and analyzing the level of practice of the Bank of Baghdad for social responsibility and the impact on their financial performance during the period. To measure the independent variable (CSR), the researcher used the CSR Disclosure Index and relied on the ROA as an indicator to measure the dependent variable (financial performance). The results of the research showed the main hypothesis of the research, which states that the social responsibility of the banks has no significant impact on the financial performance. In relation to the disclosu
... Show MoreDrilling solutions can be considered as an intricate mixture comprising of number of chemical additives which aid specific needs such as controlling the rheological properties and reducing corrosion. Inhibitors are substances that are added in small concentrations to corrosive environment to decrease the corrosion. Their applications can be found in drilling equipments. The effect of adding Zinc Sulphate and Carboxymethyl Cellulose to study their influence on the corrosion of carbon steel in Bentonite mud has been evaluated using Weight Loss Technique. This study focuses on determining rheological properties and corrosion characteristics. Results show CMC and ZnSO4 work as inhibitors when added to the Bentonite with inhibition
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The hotel sector is one of the most vital sectors exposed to risks, and the authorities concerned with control must take their active and influential role in putting the hotel sector on the right track and compatible with the internationally approved approaches, and the importance of auditing the performance of the hotel sector in light of the (Covid-19) pandemic is embodied in the fact that it gives a clear and realistic picture to the management and regulatory bodies about the performance and activities of this sector and the shortcomings and deviations that must be addressed, and also helps government decision makers to ob
... Show MoreThe integer simulation and development finite impulse response (FIR) filters taking into account the possibilities of their realization on digital integer platforms are considered. The problem statement and solution of multifunctional synthesis of digital FIR filters such a problem on the basis of the numerical methods of integer nonlinear mathematical programming are given. As an several examples, the problem solution of synthesis FIR-filters with short coefficient word length has been given. The analysis of their characteristics is resulted. The paper discusses issues of modeling and synthesis of digital FIR filters with provision for the possibilities of their implementation on digital platforms with integer computation arithme
... Show MoreIn the current research, the work concentrated on studying the effect of curvature of solar parabolic trough solar collector on wind loading coefficients and dynamic response of solar collector. The response of collector to the aerodynamic loading was estimated numerically and experimentally. The curvature of most public parabolic trough solar collectors was investigated and compared. The dynamic response of solar collector due to wind loading was investigated by using numerical solution of fluid-structure interaction concept. The experimental work was done to verify the numerical results and shows good agreement with numerical results. The numerical results were obtained by using finite element software package (ANSYS 14). It was found
... Show MoreIn this paper, several combination algorithms between Partial Update LMS (PU LMS) methods and previously proposed algorithm (New Variable Length LMS (NVLLMS)) have been developed. Then, the new sets of proposed algorithms were applied to an Acoustic Echo Cancellation system (AEC) in order to decrease the filter coefficients, decrease the convergence time, and enhance its performance in terms of Mean Square Error (MSE) and Echo Return Loss Enhancement (ERLE). These proposed algorithms will use the Echo Return Loss Enhancement (ERLE) to control the operation of filter's coefficient length variation. In addition, the time-varying step size is used.The total number of coefficients required was reduced by about 18% , 10% , 6%
... Show Moreتركز هذا البحث على تصميم عدسة كهروستاتيكية ثلاثية الاقطاب اسطوانية الشكل متحدة المركز ومفصولة بفتحة هوائية . تم حل معادلة لابلاس بطريقة كثافة الشحنة في مجال بصريات الجسيمات المشحونة اللانسبية وبغياب تأثيرات شحنة الفضاء إن توزيع الجهد المحوري لعدسة ثلاثية كهروستاتيكية تم حسابه باستخدام كثافة الشحنة الموزعة على الاقطاب، الناتجة من تسليط فولتية معينة على الاقطاب اعتمادا على ق
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