This paper develops a nonlinear transient three-dimensional heat transfer finite element model and a rate independent three-dimensional deformation model, developed for the CO₂ laser welding simulations in Al-6061-T6 alloy. Simulations are performed using an indirect coupled thermal-structural method for the process of welding. Temperature-dependent thermal properties of Al-6061-T6, effect of latent heat of fusion, and the convective and radiative boundary conditions are included in the model. The heat input to the model is assumed to be a Gaussian heat source. The finite element code ANSYS12, along with a few FORTRAN subroutines, are employed to obtain the numerical results. The benefit of the proposed methodology is that it

The results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by u

In recent years, various methods have been developed to enhance the characteristics of asphalt pavement in order to face the continuous challenges of increasing traffic loads and changing climate conditions. One of the most popular and successful methods is modifying the asphalt mixtures or asphalt binder with the addition of polymers. Therefore, two types of Polyethylene (PE) polymer, High-Density PE (HDPE) and Low-Density PE (LDPE), are used in this research. Two methods were applied to prepare PE-modified asphalt mixtures: Semi-Wet Method (S-WM) and Dry Method (DM). The findings of the investigation indicated that the addition of PE polymer can reduce the wear loss of aggregate. In general, the experimental results revealed that asphalt

Abstract:-

The phenomenon of financial and administrative corruption is not the result today, but not tied to time or designated place, he is the scourge is rampant in all countries of the world, without exception, those developed and developing, a phenomenon that crossed national boundaries and become withstand a global character, and corruption is limited to communities of particular economic systems without the other, but suffered Throughout history most societies to varying degrees, Iraq is one of the countries that suffered and continues to suffer from corruption, which has become, B grumble in most of the Iraqi state institutions, especially after the occupation in 2003 as administrative corruption in Iraq arrived i

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.

At the end of 2019, a new form of Coronavirus (later dubbed COVID-19) emerged in China and quickly spread to other regions of the globe. Despite the virus’s unique and unknown characteristics, it is a widely distributed infectious illness. Finding the geographical distribution of the virus transmission is therefore critical for epidemiologists and governments in order to respond to the illness epidemic rapidly and effectively. Understanding the dynamics of COVID-19’s spatial distribution can help to understand the pandemic’s scope and effects, as well as decision-making, planning, and community action aimed at preventing transmission. The main focus of this study is to investigate the geographic patterns of COVID-19 disseminat

Objective: To assess prospectively functional outcome of interlocked intramedullary nailing fixation in management of closed tibia shaft fractures. Methodology: This prospective study included 134 patients with closed shaft tibia fractures with age 18-60 years and isolated closed fracture of shaft of tibia. The fractures were fixed by interlocking intramedullary nail. At follow-up after 12 months postoperatively, the functional outcome was assessed radiographically for the sign of union and clinically according to Klemm-Borner criteria. Results: The mean age was 38.55 years. Out of 134 patients, 55.2% were male. The cause was road traffic accident in 44.8%, majority of the fracture occur in the mid-shaft (41.8%), and oblique fracture was th

One of the most important intellectual issues, which receive attention is the issue of modernity, it has occupied the scholars of all time. However, modern poetry used to have special care in Iraq and in the Arab countries .. it is not strange that the concept of modernity is linked to history .. or having history as the most important dimension of its dimensions .. because Arab poetry is historical and it is moving into an area of ​​the past that is still active in terms of language and literary image .. When some poets found that changing and modernizing poetry became a necessity of evolution, and one of the fundamentals of modernization, the cultural impact did not respond to the desire of poets, and their impulse in modern poetry

The research aims to Applied Study in the nature of the impact of information asymmetry for brokerage firms in the common stock trading, The research included the theoretical concepts associated with each of the brokerage firms ,information asymmetry and common stock trading, It used the financial methods on the practical side of the information asymmetry for brokerage firms based in the sector as well as trading volume and spread for common stock , The community of the research included the Iraq Stock Exchange,the sample of research the companies listed which have been trading on its stock for the period August 2015 until December 2015 as well as brokerage firms

amounting to 47 brokerage firm. The resea

Iraq has the distinction of being a great potential of non-renewable natural resources,
especially crude oil and natural gas. Since the discovery of crude oil at the beginning of the
twentieth century in Iraq. Although the different of investment types, it contributed to the oil
sector in the provision of financial resources to the state treasury , since that date until the
present time.
Search has been marked by division ((The foreign investment in the oil sector in Iraq after
2003)) into three sections. The first section included a brief history of the development of
Iraq's oil potential in terms of oil reserves, and oil fields, and the quantities of production and
export. The second section reviewed the investm