This work is concerned with the design and performance evaluation of a shell and double concentric tubes heat exchanger using Solid Works and ANSY (Computational Fluid Dynamics).

Computational fluid dynamics technique which is a computer-based analysis is used to simulate the heat exchanger involving fluid flow, heat transfer. CFD resolve the entire heat exchanger in discrete elements to find: (1) the temperature gradients, (2) pressure distribution, and (3) velocity vectors.  The RNG k-ε model of turbulence is used to determining the accurate results from CFD.

The heat exchanger design for this work consisted of a shell and eight double concentric tubes. The number of inlets are three and that of o

Biometrics is widely used with security systems nowadays; each biometric modality can be useful and has distinctive properties that provide uniqueness and ambiguity for security systems especially in communication and network technologies. This paper is about using biometric features of fingerprint, which is called (minutiae) to cipher a text message and ensure safe arrival of data at receiver end. The classical cryptosystems (Caesar, Vigenère, etc.) became obsolete methods for encryption because of the high-performance machines which focusing on repetition of the key in their attacks to break the cipher. Several Researchers of cryptography give efforts to modify and develop Vigenère cipher by enhancing its weaknesses.

The evolution of cryptography has been crucial to preservation subtle information in the digital age. From early cipher algorithms implemented in earliest societies to recent cryptography methods, cryptography has developed alongside developments in computing field. The growing in cyber threats and the increase of comprehensive digital communications have highlighted the significance of selecting effective and robust cryptographic techniques. This article reviews various cryptography algorithms, containing symmetric key and asymmetric key cryptography, via evaluating them according to security asset, complexity, and execution speed. The main outcomes demonstrate the growing trust on elliptic curve cryptography outstanding its capabi

The confirming of security and confidentiality of multimedia data is a serious challenge through the growing dependence on digital communication. This paper offers a new image cryptography based on the Chebyshev chaos polynomials map, via employing the randomness characteristic of chaos concept to improve security. The suggested method includes block shuffling, dynamic offset chaos key production, inter-layer XOR, and block 90 degree rotations to disorder the correlations intrinsic in image. The method is aimed for efficiency and scalability, accomplishing  complexity order for n-pixels over specific cipher rounds. The experiment outcomes depict great resistant to cryptanalysis attacks, containing statistical, differential and brut

A submoduleA of amodule M is said to be strongly pure , if for each finite subset {ai} in A , (equivalently, for each a ?A) there exists ahomomorphism f : M ?A such that f(ai) = ai, ?i(f(a)=a).A module M is said to be strongly F–regular if each submodule of M is strongly pure .The main purpose of this paper is to develop the properties of strongly F–regular modules and study modules with the property that the intersection of any two strongly pure submodules is strongly pure .

New data on jumping spiders (Salticidae) and tangle-web spiders (Theridiidae) of Armenia are provided on the basis of recently collected specimens in various regions of Armenia. One species, Ballus rufipes (Simon, 1868) is recorded as new to the Caucasus Region, in addition to the following species: Neon reticulatus (Blackwall, 1853), Pellenes brevis (Simon, 1868), Salticus scenicus (Clerck, 1757) and Synageles dalmaticus (Keyserling, 1863) that belong to a family Salticidae, are recorded in Armenia for the first time.
A further 7 species of Theridiidae are recorded in Armenia for the first time Kochiura aulica (C. L. Koch, 1838), Steatoda albomaculata (De Geer, 1778), Steatoda bipunctata (Linnaeus, 1758), Steatoda castanea Clerk, 175

Mental stress occurs due to the effect of time that passes at an accelerated pace and doing business imposed by the speed of the match with his speed in light of the vast amount of audio and visual information through scientific progress and media workers, as well as the impact of physical factors associated with doing business, such as noise and congestion .... . etc.. The relationship of the individual to take a negative surroundings have devastating effects on the cognitive process as a whole dimension. This creates a sense of helplessness with the depletion voltage to a state of mental stress, so The problems from the standpoint of Aljhtalt scientists are basically cognitive problems appear to exist when it happens to the ind

      يعد موضوع  الشباب- في الوقت الحاضر -  من الموضوعات المهمة  التي  يهتم  بها  علم النفس  والتربية  والأجتماع  والصحة . بل أن الدول  المتقدمة  تهتم بشبابها  أيمانآ بأن تقدم  الأمة لايقوم الاعلى الأمكانيات البشرية من الشباب .

      ومما لاشك  فيه  أن  دخول الشباب  الى عالم  المجتمع  الجامعي  يطرح عليه وبشدة مشكلة التصرف م

The research aims to identify the level meta the memory as well as the point of control and their relationship with the university students and for the purpose of verifying that these of a scale meta the memory prepared by Brewer and British as well as testing and point of control, prepared by the Nawski where the number of items of a scale meta the memory (57) ,Items The test point of the control setting, the number of items (40) items has been to make sure _ psychometrical characters have been applied instrumentson a random sample amounted to (200) students were selected in a stratified random and showed the results of research show that members of the research sample have awareness of how to work their memories, where the average grad