The purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy properties were obtained by using analysis of variance which applied with the help of (Minitab18) software. The variables of quenching heat treatment were austenitizing temperature (985 C˚,1060 C˚),a soaking times (50,70 and 90 minutes) respectively, Percentage of volumetric fractions of nanoparticles with three different levels(0.01, 0.03 and 0.08 %) were prepared by dispersing nanoparticles that are (α-Al2O3,TiO2 and CuO) with base fluids (De-ionized water, salt solution and engine oil).The specimens were tempered at 700°C after quenching of nanofluids for (2 hours).The results for ( S/N) ratios showed the order of the factors in terms of the proportion of their effect on hardness, and wear rate properties as follow: Austenitizing temperature ( 1060 C˚),Type of base media (salt solution), Nanoparticles type (CuO), Percentage of nanoparticles (0.08%) and Soaking time(90min) was the least influence while for the impact energy were as follows: Type of base media (oil), Austenitizing temperature (985C˚), Percentage of nanoparticles (0.01%), Nanoparticles type (α-Al2O3) and last soaking time (50min).
In order to implement the concept of sustainability in the field of construction, it is necessary to find an alternative to the materials that cause pollution by manufacturing, the most important of which is cement. Because factory wastes provide siliceous and aluminous materials and contain calcium such as fly ash and slag that are used in the production of high-strength geopolymer concrete with specifications similar to ordinary concrete, it was necessary for developing this type of concrete that is helping to reduce CO2 (dioxide carbon) in the atmosphere. Therefore, the aim of this study was to study the influence of incorporating various percentages of slag as a replacement for fly ash and the effect of sl
... Show MoreA prey-predator interaction model has been suggested in which the population of a predator consists of a two-stage structure. Modified Holling's disk equation is used to describe the consumption of the prey so that it involves the additional source of food for the predator. The fear function is imposed on prey. It is supposed that the prey exhibits anti-predator behavior and may kill the adult predator due to their struggle against predation. The proposed model is investigated for existence, uniqueness, and boundedness. After determining all feasible equilibrium points, the local stability analyses are performed. In addition, global stability analyses for this model using the Lyapunov method are investigated. The chance of occurrence of loc
... Show MoreThis research aimed to examine the correlation and influence of leader-member exchange in the organizational citizenship behavior in the existence of organizational trust as mediator variable among workers in ministry of migration and displaced, has been collecting data and information relating to research by designing questionnaire was distributed to the stratified random sample included (56) member of the workers in the ministry mentioned, and through the use of several statistical method were the main findings of research was the existence of a correlation relationship and influence between leader- member exchange and organizational trust, while the results confirmed no correlation and influen
... Show MoreAbstract: Two different shapes of offset optical fiber was studied based on coreless fiber for refractive index (RI)/concentration (con.) measurement, and compare them. These shapes are U and S-shapes, both shapes structures were formed by one segment of coreless fiber (CF) was joined between two single mode (SMF) lead in /lead out with the same displacement (12.268µm) at both sides, the results shows the high sensitive was achieved in a novel S-shape equal 98.768nm/RIU, to our knowledge, no one has ever mentioned or experienced it, it’s the best shape rather than the U-shape which equal 85.628nm/RIU. In this research, it was proved that the offset form has a significant effect on the sensitivity of the sensor. Addi
... Show MoreThe problem of this research lies in the fact that there is a lack of accurate scientific perceptions about the size of the use of Iraqi women’s social networking sites and the motives behind this use and the expectations generated by them.
The goals of the research are as follows:
1- Determine the extent of Iraqi women’s use of social networking sites (Facebook, YouTube, twitter, and Instagram).
2- Investigative the motives behind the use of social networking sites by Iraqi women.
3- Detecting the repercussions of Iraqi women’s use of social networking sites (Facebook, you tube, twitter, and Instagram).
The research is classified as a descriptive one. The researchers use the survey methodology. The research commu
THE EFFECT OF SPREACL of KNOWLEDGE ON ETHICS
The research focuses on determining the role of customer relationship management in improving financial performance by surveying the opinions of a number of employees of a number of Iraqi private banks. The customer has become the focus of attention and the most important factors of success and profitability and competition. Therefore, decisions related to the customer are important decisions that support the process of making, And follow-up of administrative decisions, including financial decisions aimed at improving the financial performance of banks and distinguish them from competitors. Thus, the techniques used in customer relations management programs to collect, analyze and use data and information have beco
... Show MoreThe summary:
This research paper presents a standard economic study. This study aims to build an economic standard form of the investment effect in Human Capital on Economic Growth in Algeria. The study showed that there is an inverse relationship between the investment and human capital. This is expressed by expending on education and economic growth. This contradicts with the economic theory. Such matter could be explained by that expending on education does not contribute in the economic growth. This refers to that the education sector result does not employee or save jobs. Thus, it does not contribute in growth; in addition, the Algerian economy depends on petrol in the first class. This means the ab
... Show MoreThe researcher tried to show the importance of obligation with the rules of professional conduct set by the Association of Accountants and Auditors of Iraqis when expressing an opinion the financial statements submitted tax administration and enhance the confidence of these lists, and adopted in the tax settling accounts process and its impact on tax revenues, and touched a researcher at the theoretical side of the search to the problem of research and of my Is there a trace of non- not to obligation by the rules of professional conduct in Iraq affect the tax revenue with the rules of professional conduct in tax revenue for companies research sample, the research aims to study the rules of professional conduct set by the Associatio
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