The purpose of our work is to report a theoretical study of electrons tunneling through semiconductor superlattice (SSL). The (SSL) that we have considered is (GaN/AlGaN) system within the energy range of ε < Vo, ε = Vo and ε > Vo, where Vo is the potential barrier height. The transmission coefficient (TN) was determined using the transfer matrix method. The resonant energies are obtained from the T (E) relation. From such system, we obtained two allowed quasi-levels energy bands for ε < VO and one band for ε  VO.

Language is the realistic and sensitive basis for any communication between two or more parties. It is an important workshop that prepares meanings and coding them according to a linguistic structure governed by agreed rules that speak to and coexist with everyone.

Whereas the forms of communication are: personal, mediator and mass, none of them can move away from language in their dealings and communication patterns. Since each has its own characteristics and skills, it must be launched in its fields through verbal and non-verbal symbols and wears the elements of influential language as intended.

It makes the recipient face two things: whether he fails to understand those symbols hence its purpose fail, or he meditates s

A biconical antenna has been developed for ultra-wideband sensing. A wide impedance bandwidth of around 115% at bandwidth 3.73-14 GHz is achieved which shows that the proposed antenna exhibits a fairly sensitive sensor for microwave medical imaging applications. The sensor and instrumentation is used together with an improved version of delay and sum image reconstruction algorithm on both fatty and glandular breast phantoms. The relatively new imaging set-up provides robust reconstruction of complex permittivity profiles especially in glandular phantoms, producing results that are well matched to the geometries and composition of the tissues. Respectively, the signal-to-clutter and the signal-to-mean ratios of the improved method are consis

The specifications of lubricating oil are fundamentally the final product of materials that have been added for producing the desired properties. In this research, spherical nanoparticles copper oxide (CuO) and titanium oxides (TiO₂) are added to SAE 15W40 engine oil to study the thermal conductivity, stability, viscosity of nano-lubricants, which are prepared at different concentrations of 0.1%, 0.2%, 0.5%, and 1% by weight, and also their pour point, and flash point as five quality parameters. The obtained results show that CuO nanoparticles in all cases, give the best functionality and effect on engine oil with respect to TiO₂. With 0.1 wt. % concentration, the thermal conductivity of CuO/oil and TiO₂/

         The Feedback Concept has been spread as an organized trend for scientific research since it has a significant importance for human behavior and how it has been directed and controlled by the individual, feedback has numerous definitions but the simplest definition is; feedback is the information received by the individual from the output of his behavior, In addition to the mutual relationship between the individual and the stimulation that provide him with the basic information by the biological control of his behavior, Since feedback cannot be accomplished without receiving information from the inner and outer environment, the biological and physiological information become the ma

Abstract

All the economic  units whether productive or service units , strive to achieve specific objectives , their presence and continuity depend on them and the quality of the performance and service present to the society . This units to be able to achieve their objectives , must own basic assets to perform the activities , and apply laws , systems , and instructions , in addition to legal , managerial , and financial authorities . So this units to endeavor maintain this assets , in addition to sound application of laws ,systems . and procedures to enhance their performance . For this purpose arise the role of internal control and internal check in maintenance of assets and sound application of&n

Lead-acid batteries have been used increasingly in recent years in solar power systems, especially in homes and small businesses, due to their cheapness and advanced development in manufacturing them. However, these batteries have low voltages and low capacities, to increase voltage and capacities, they need to be connected in series and parallel. Whether they are connected in series or parallel, their voltages and capacities must be equal otherwise the quality of service will be degraded. The fact that these different voltages are inherent in their manufacturing, but these unbalanced voltages can be controlled. Using a switched capacitor is a method that was used in many methods for balancing voltages, but their respons