With the revolutionized expansion of the Internet, worldwide information increases the application of communication technology, and the rapid growth of significant data volume boosts the requirement to accomplish secure, robust, and confident techniques using various effective algorithms. Lots of algorithms and techniques are available for data security. This paper presents a cryptosystem that combines several Substitution Cipher Algorithms along with the Circular queue data structure. The two different substitution techniques are; Homophonic Substitution Cipher and Polyalphabetic Substitution Cipher in which they merged in a single circular queue with four different keys for each of them, which produces eight different outputs for every single incoming letter. The present work can be applied efficiently for personal information security and network communication security as well, and the time required for ciphering and deciphering a message is less than 0.1 sec.
The issue of the Circular Economy is not a new issue to several countries, especially the developed ones. Here in Iraq it is considered newly introduced, despite the few attempts to establish projects that concern recycling most of them were doomed to fail, due to two main reasons: the first one is the financial and administrative corruption widespread in all departments of the country, the second one is the priorities of public spending. It is well known that Iraq was subjected to two major attacks, the ISIS entry attack in 2014 to Iraq. ISIS occupied about a third of Iraqi lands which resulted in a collapse in oil prices, as Iraq depends almost entirely on oil revenues in its budget which is the second attack. This made the Iraqi governme
... Show MoreIn cyber security, the most crucial subject in information security is user authentication. Robust text-based password methods may offer a certain level of protection. Strong passwords are hard to remember, though, so people who use them frequently write them on paper or store them in file for computer .Numerous of computer systems, networks, and Internet-based environments have experimented with using graphical authentication techniques for user authentication in recent years. The two main characteristics of all graphical passwords are their security and usability. Regretfully, none of these methods could adequately address both of these factors concurrently. The ISO usability standards and associated characteristics for graphical
... Show MoreA growing and pressing need for Speech Enhancement Algorithms (SEAs) has emerged with the proliferation of hearing devices and mobile devices that aim to improve speech intelligibility without sacrificing speech quality. Recently, a tremendous number of studies have been conducted in the field of speech enhancement. This study aims to map the field of speech enhancement by conducting a systematic literature review to provide comprehensive details of recently proposed SEAs. This systematic review aims to highlight research trends in SEAs and direct researchers to the most important topics published between 2015 and 2024. It attempts to address seven key research questions related to this topic. Moreover, it covers articles available
... Show Moreيُمثل التوسع الحضري أحد أبرز التحولات الديموغرافية العالمية. وفي العراق، يكتسب هذا التحول بُعداً استثنائياً نتيجة للتغيرات السياسية، والأمنية، والاقتصادية الجذرية الممتدة من عام 1997 وحتى 2025، والتي أفرزت تبايناً مكانياً حاداً في مسارات النمو السكاني بين المراكز الحضرية. استندت هذه الدراسة إلى تحليل بيانات رسمية لـ 12 مركزاً حضرياً رئيسياً. وكشفت النتائج عن فجوة ديموغرافية واسعة؛ إذ برزت مدن إقليم كردستان (ال
... Show MoreThe influences of the Cu substitution at Hg site in the HgOd layer, upon the
microstructure, Tc and oxygen content of Hg-1223 have been investigated. High
temperature superconductor with a nominal composition Hg1-xCuxBa2Ca2Cu3O8 + δ for
Cu ( 0 £ x £ 0.5) have been prepared by the two-steps solid state reaction method
under optimum conditions. XRD showed a tetragonal structure with a high ratio of
Hg-1223 superconductor phase. Tc enhancement has been determined with the Cu
concentration was is found to be Tc = 153 K for x = 0.3, while the oxygen content
observed variously with Cu concentration. Hg1-xCuxBa2Ca2Cu3O8+δ structure, oxygen
content and Tc behavior have been discussed.
This study explored the feasibility of removing nickel (Ni) and Pb (II) from water solutions using the adsorption technique by cellulose recovered from office paper waste. Metal removal is required to reduce the direct or indirect exposure of industrial waste to the environment, due to its potential for harm to human health and ecosystems. The release criterion is maintained to keep the efficient wastewater treatment of the metals of concern, which are toxic to both humans and other organisms. The cellulose was first prepared from office paper waste. The removal values can be rationalized as follows: Lead removal efficiencies of were obtained upto %95.0632, while the removals of nickel were obtained as 54.3866%. The adsorption proce
... Show MoreInherent fluctuations in the availability of energy from renewables, particularly solar, remain a substantial impediment to their widespread deployment worldwide. Employing phase-change materials (PCMs) as media, saving energy for later consumption, offers a promising solution for overcoming the problem. However, the heat conductivities of most PCMs are limited, which severely limits the energy storage potential of these materials. This study suggests employing circular fins with staggered distribution to achieve improved thermal response rates of PCM in a vertical triple-tube heat exchanger involving two opposite flow streams of the heat-transfer fluid (HTF). Since heat diffusion is not the same at various portions of the PCM unit,
... Show MoreDensity Functional Theory at the generalized-gradient approximation level coupled with large unit cell method is used to simulate the electronic structure of (II-VI) zinc-blende cadmium sulfide nanocrystals that have dimensions 2-2.5 nm. The calculated properties include lattice constant, conduction and valence bands width, energy of the highest occupied orbital, energy of the lowest unoccupied orbital, energy gap, density of states etc. Results show that lattice constant and energy gap converge to definite values. However, highest occupied orbital, lowest unoccupied orbital fluctuates indefinitely depending on the shape of the nanocrystal.