Contemporary life is racing against time in its temptations and variables, and it has become shaped and changed in an amazing way in its various aspects and fields. This was facilitated by intellectual and scientific communication between civilizations, and the rapid progression in successive inventions and discoveries in the fields of science and arts of knowledge. This contributed to a great economic and commercial renaissance. Then, these economic developments entered the world into a very strong competition, which forced producers to calculate all production costs, to reach the highest profits by reducing the price of the produced commodity on the one hand, and achieving quality in appearance (especially) on the other hand. Since the machine represents an important part in the production and manufacturing process, its survival and serviceability are essential to the course of production and avoiding loss. Therefore, it was imperative for project owners to provide specialists from experts and technicians to provide the required service according to the technical rules, for the operation of those tools and devices. Thus, the maintenance contract appears as one of the necessary contemporary contracts accompanying technical and economic development. The importance of this contract and the need for its presence have increased due to a number of factors, the most prominent of which are: 1. The employer's maintenance of the machines may cost him a lot, while it would not cost him much if he entrusted its maintenance to a maintenance company. This is due to the following: A- The employer's maintenance requires him to provide an integrated work team for maintenance only. These may only be needed a few times, which is not commensurate with the amount he will pay them, especially since some of them may receive a high salary because they are rare engineers, for example. B- Maintenance may sometimes require precise machines and devices, the purchase of which may cost the employer more than if he contracted with a company that appointed itself for this purpose. 2. The increased use of machines and devices to accomplish work in this era, as they have entered most fields. Means of transportation, such as cars, planes, ships and trains, require maintenance, machines in factories require maintenance, electrical devices of all kinds require maintenance, in addition to buildings and what they in turn require in terms of maintenance. 3. Maintaining production machines preserves them and keeps them away from breakdowns as much as possible. This is because the breakdown of these machines, even for a short period, may cause large and severe losses.
In this research, the Williamson-Hall method and of size-strain plot method was employed to analyze X- ray lines for evaluating the crystallite size and lattice strain and of cadmium oxide nanoparticles. the crystallite size value is (15.2 nm) and (93.1 nm) and lattice strain (4.2 x10−4 ) and (21x10−4) respectively. Also, other methods have been employed to evaluate the crystallite size. The current methods are (Sherrer and modified Sherrer methods ) and their results are (14.8 nm) and (13.9nm) respectively. Each method of analysis has a different result because the alteration in the crystallite size and lattice strain calculated according to the Williamson-Hall and size-strain plot methods shows that the non-uniform strain in nan
... Show MoreBackground:sThe aims of this study were to evaluate and compare the ability of three different techniques to obdurate simulated lateral canals, evaluate the effect of the main canal curvature on obturation of lateral canals and compare the gutta-percha penetration between coronal and apical lateral canals. Materials and methods: Resin blocks with 30 straight and 30 curved were used in this study. Each canal has two parallel lateral canals. The main canal has 0.3 mm apical diameter and 0.04 taper. The canals were divided into six groups according to canal curvature and obturation techniques used (n=10): Groups C1 and C2: straight and curved canals obturated with continuous wave technique using E&Q masterTM system. Groups O1 and O2: straight
... Show MoreA comparative study was carried out on ecological and genetical adaptation of three Iraqi
freshwater snails, Physa acuta, Melanopsis buccinoidea and Melanoides tuberculata, in
respect to acute toxicity of heavy metals (Zn, Cd and Hg). Longevity are used as poisoning
tolerance criterion. LT 50 and LT 100 were determined for the studied snails at (0.5, 1, 5, and
10 ppm), for the three metals. Results indicated that Physa acuta had a higher tolerance than
Melanopsis buccinoidea and Melanoides tuberculata, which was the lower one. Previous
exposure to heavy metals in the original habitat was affecting on experimental tolerance and
no relationships of physical and chemical factors (total hardness, temperature, D. O. and
Receipt date:10/27/2021 accepted date:12/15/2021 Publication date:31/12/2021
This work is licensed under a Creative Commons Attribution 4.0 International License.
The phenomenon of extremist extremism (terrorism) was one of the most prominent issues that took a large space in the twenty-first century, in which cognitive motives were mixed with strategic and ideological motives, leading to the emergence of terrorist extremi
... Show MoreThe study aimed to identify the treatment of the press image of the Great Return Marches in the French international news agency AFP by knowing the most important issues, their direction and the degree of interest in them. The study belongs to the descriptive research, and used the survey method, within the context of the content analysis method, and the researcher relied on the content analysis form tool and the interview tool to collect data. The study population is represented in the photos published by the French News Agency about the Great Return Marches during the period (end of March / 2018 until the end of November / 2019. The researcher chose an intentional sample using the Complete Census method. The study material represented
... Show MoreThe Purpose of this research is analysis and discussion " The Effect of Insurace Company Capital Adequacy in it’s Profitafility: An Empirical Study compared the two insurance (national, Iraqi), for a period of one year (2005) and the year (2014), as it is framed theoretical side for two topics head adequacy money the insurance company, and the profitability of the insurance company, and I've been using the research methodology and analytical, in the analysis and measurement of the capital of the insurance company adequacy, and profitability of the company, as the capital adequacy ratio was measured by dividing the total capital available on the total capital rate risk, after measured and appreciated in two insurance research, while I u
... Show MoreThe study aims to know the role of governance in the consolidation of the principles of business ethics, through the application of the principles of governance and the dimensions of business ethics in the private sector. And knowledge of the validity of the hypothesis key of the current study according to which "increases the ethics of business organizations strength and coherence in the presence of the principles of governance" as it was distributed the questionnaire to a sample of a chairman and board members and managers department and heads of sections in some of the private banks. I have been using correlation analysis and regression testing (t) to see the moral differences and to find out the c
... Show MoreAbstract This study aims to compare British war poetry of the First World War with Iraqi poetry from the mid-20th century with special reference to Iraqi war poetry of the 1980’s Iraq-Iran War and the period that followed it. It will also investigate the influence of the designated British war poetry on the chosen body of Iraqi poetry. Through the comparison of sample poems the study presents, firstly, the direct influence of the British poetry of the Great War and its translation which formed the seeds of a more radical movement in Iraqi poetry during the 1980’s Iran/Iraq War and the period that followed it. The study also presents a comparison of the works of British and Iraqi civilian poets during and after the war time and their con
... Show MoreThe topic of (pilgrims) of the old and modern subjects at the same time, as it extends his foot and is associated with the beginning of speech and argument, a modern because it is based on studies and research (and the theory of pilgrims) from (Austin and Cyril) through (Charles Breman) to (Aristotle) ), It is worth mentioning here to mention the role of (Hazem al - Qartagni) in mentioning the value of the pilgrimage of hair and saying the use of persuasion in the hair, is palatable and acceptable. Hence our research applied these views, and we chose the pendants as a model for that matter.