Bragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the

Organic permeable‐base transistors (OPBTs) show potential for high‐speed, flexible electronics. Scaling laws of OPBTs are discussed and it is shown that OPBT performance can be increased by reducing their effective device area. Comparing the performance of optimized OPBTs with state‐of‐the‐art organic field‐effect transistors (OFETs), it is shown that OPBTs have a higher potential for an increased transit frequency. Not only do OPBTs reach higher transconductance values without the need for sophisticated structuring techniques, but they are also less sensitive to parasitic contact resistances. With the help of a 2D numerical model, the reduced contact resistances of OPBTs are explained by a homogeneous injection of current acros

This research is based on the study of common praise in Mutanabbi and Ibn Hani Al-Andalusi as the main purpose in poetry poets, and balance between them;

  The research was divided into two topics, presented by introductory introduction for the purpose of praise, and the concept of budget in Arab criticism, and then presented a brief overview of the lives of poets.

  In the first section, I dealt with the common objectivity of the poets, such as the subject of sincerity in praise, hyperbole in the person of Mamdouh, and self-esteem when asked, in addition to the most common characteristics in t

Six proposed simply supported high strength-steel fiber reinforced concrete (HS-SFRC) beams reinforced with FRP (fiber reinforced polymer) rebars were numerically tested by finite element method using ABAQUS software to investigate their behavior under the flexural failure. The beams were divided into two groups depending on their cross sectional shape. Group A consisted of four trapezoidal beams with dimensions of (height 200 mm, top width 250 mm, and bottom width 125 mm), while group B consisted of two rectangular beams with dimensions of (125 ×200) mm. All specimens have same total length of 1500 mm, and they were also considered to be made of same high strength concrete designed material with 1% volume fraction of steel fiber.

Human resources constitute the most important recourses that the organization owned today, as it may have developed financial and technology resources to achieve their goals, but they are not able to use it with required efficiency and effective and quality desired unless there is human resources that have good skills, experiences and talents that able to directing and exploited ideally that compatible  with market requirements, where today's market and business organizations which compete naturally inherent talent, so the task is to attracting and developing talented resources and preservation these talented resources from the challenges that facing organizations. 

The research seek to achieve

The growing population and the rising standard of living in cities as well as the increased commercial, industrial and agricultural activities around the world led to
massive production of waste containing different materials and one of them is the municipal solid waste (MSW), so there is a major problem facing the cities around the world about the waste, how to collect, transfer it and how to discard it. Because the accumulation of wastes, whether in the city alleys or in its squares and especially in its residential areas affect the health of their populations besides this situation will be a major indication of the deteriorating quality of life in the city, as hygiene considered a fundamental criterion for the city beauty as well

This research came with the aim of showing the impact of governance mechanisms on tax avoidance practices, and in light of this, the financial data of the joint stock companies (industrial, service, agricultural, and hotels) listed in the Iraq Stock Exchange amounting to (35) companies were collected during the period (2009-2020). Through the financial reports published on the market website, multiple linear regression analysis was used as a tool to study the relationship between variables, and (Eviews 12) program was used for analysis and hypothesis testing. To achieve the objectives of the research,(administrative ownership, board size, board independence, women's membership) was adopted as an indicator of the dimensions of governance, an

The current research aims to test the impact of the strategy of merger (as an explanatory variable) in human resources management practices (as a response variable), and the importance of the subject being an important topic that mimics the Iraqi environment, where has seen many mergers that have not been addressed by former researchers in the field. In addition, the future prospects carry many mergers, and the problem of research was the lack of understanding among departments in how to manage the integration and deal with it, on the basis of scientific which reflected negatively on the practices of human resources management, and the research was based on two main hypotheses Six sub-hypotheses emerge to explore the correlation

The aim of this research is to demonstrate the impact of credit risk on the banks of the study sample on the granting of loans and credit facilities, and try to reduce the size of credit risk to banks as a result of granting loans and credit facilities, credit risk is the oldest form of risk in financial markets. Every financial institution takes a degree of risk when it gives loans and credit facilities to companies and customers, It is exposed to financial losses when some borrowers fail to repay their loans as agreed, and at the same time credit facilities are the most profitable operations of the bank as it is the most profitable banking operations than other operations, so it represents the research communit