Tikrit Journal of Engineering Sciences

The energy needs have been enlarged extremely. The electricity power generators are utilized and distributed in the national (local) grid. Many factors can affect on national distribution grid stability, such as load flow. It is utilized to evaluate various operating states for energy generation and distribution systems. In this article, six different generators are distributed in Kufa (Iraq) cement plant based on load flow balancing. Behinds, these distributed generators work under two modes, such that island mode and regular operation. The proposed modules are analyzed using Electrical Transient Analyzer Program (ETAP) software. The achieved analysis can help to reduce the distribution grid shutdown. Furthermore, the load balancing can be achieved at both modes. Load flow analysis takes consideration for the total energy demands and losses of the system separately in order to balance load and optimize operation. The results show that the buses’ voltage drop in island mode was more than the voltage drop when the local grid connected to the national grid. The problems of drop voltages and power factor were solved.

In the world, optimizing energy and finding new sources is important because of the increased consumption that occurred in all aspects of life. Nowadays, the world suffers of the reduction in the fossil fuel continuously. One solution to this problem is the sun and the photovoltaic (PV) cell. To get the benefits of PV, the DC/DC and DC/AC converters and inverters are combined in one set to get the better usage of these capabilities. Induction motor (IM) is the horsepower in the industry and will be considered the load in this work. The DC/DC Converter is used for control of IM speed in combination with maximum power point tracking (MPPT). Temperature and radiation change constantly over time, and the maximum energy should be tracked. This follow-up was performed using Incremental Conductance method (INC). INC is control buck-boost duty cycle converter. We get the best performance in INC technology and have less effect on the system. This algorithm uses INC of the MPPT to control half of horse power of IM. The sine pulse width modulation technique (SPWM) is used with three level inverters. Simulation on the Three-phase proves the efficiency of the suggested technique.

The response surface methodology (RSM) was adopted in ths study to evaluate the influence, interplay and interaction of various process variables on the biodiesel yield using methanol and castor oil as feedstocks in the presence of bovine bones as bio-catalyst.Twenty experimental runs were designed using central composite design (CCD). RSM statistical model of second order was developed. Analysis of variance (ANOVA) tests were performed on the model to find the relative influence of the process variables. An optimum yield of 95.12% was obtained at 60 0C reaction temperature, 120 minutes reaction time, molar to oil ratio 6:1, catalyst concentration of 10 % w and a stirring rate of 900 rpm. The experimental conditions under which biodiesel was synthesized in this study was compared with those of previous studies .It can therefore be inferred that , the conditions herein is competing with prior established conditions. The biodiesel was found to possess fuel properties that fall within acceptable limits and green metrics estimated showed compliance of the process with the diictates of green and sustainable chemistry.

This paper presents Arduino controller implementation and Simulink model in MATLAB to eliminate a selected number of harmonics in a single phase inverter. A MATLAB code is written to solve the nonlinear trigonometric that arises in the Fourier analysis of the output of the inverter. Newton’s Raphson method is adopted to find the triggering angles for the four electronic switches in the inverter. All possible combinations of these triggering instants are then computed for period of one cycle. To validate the model a practical set using Arduino controller is implemented. Frequency spectrums of the output of the inverter for both the Simulink model and the practical set are shown for the elimination of certain selected harmonics. Any other selected harmonics can be eliminated using the proposed model.

This review is based on understanding the main concept between computer engineering and mathematics based on two of their most important fields, the discrete-math and graph theory. and answering the question that was asked by many students over the years of working in the university, about the necessity of studying mathematics while majoring computer engineering. Most of the students face the same problem over years for not having the vision to connect between studying materials of their specialization and general ones, in particular between studying discrete-math engineering as in Engineering analysis, and discrete-math as in the Digital signal Processing (DSP), and between algebraic mathematics. Moreover, they do not understand the main idea of the transition between different time or frequency domains, by converting the work in real-time domain systems to work in discrete–time or frequency domain systems. And they do ignore the importance of studying graph theory, in which recent researches have proved the powerful of using graphs in learning tasks, developing an important field of computer engineering, the machine learning, where the standard neural networks (SNNs) have been developed to graph neural networks (GNNs). A figure was concluded at the end of the review to brief the importance of discrete-math developing the relationship between computer engineering in general and graph theory’s role in developing machine learning in particular.

Recently, the constructions industry begins to make concrete more sustainable, side by side, with making its high performance. This paper aims to investigate the effect of (Metakaolin and Micro Silica) when they replace cement by (8, 12 and 16) % and (6, 9 and 12) % respectively, recycled steel slag when replaces fine aggregate by (10, 20 and 30) %, and recycled mosaic tiles when replaces coarse aggregate by (33.33, 66.67 and 100) % each one another on the slump, density, absorption and compressive strength of concrete. The experimental results showed that the maximum reduction ratio of cement reach (17%) (8% of metakaolin and 9% Micro Silica) while the optimum percentage of mosaic tiles and steel slag is (100%) and (20%) respectively. The optimum percentages obtained are combining to produce three basic green mixes: 1) 17% (8% of Metakaolin and 9% of Micro Silica) only, (2) A mix containing 17% of (Metakaolin and of Micro Silica) plus 100% of recycled mosaic, (3) 17% of (Metakaolin and Micro Silica), 100% of recycled mosaic and 20% of slag. Compressive strength at (7, 28, and 60) days, modulus of rupture at (28) days, absorption, fresh and hardened density are investigated. The best improvement in compressive strength compared with reference concrete was recorded (20.06, 10.855 and 9.983) % at (7, 28 and 60) days respectively for the mix containing (17% of cementitious materials plus 100% of recycled mosaic) while the ultimate flexure strength (24) % appeared in green mix containing (17% of cementitious materials, 100% of recycled mosaic and 20% of slag). Generally, an inverse relationship between density and absorption in all trail mixes which are conducted.

Using industrial waste materials in the treatment of problematic soils is an environmentally friendly and cost-effective technique. It helps in decreasing disposal issues induced by various industrial wastes. Also, it is crucial to understand the behaviour of these waste products before use. This paper presents experimental research in the treatment of expansive soil by the utilization of iron furnace slag. Laboratory program was performed to examine the effect of iron furnace slag on enhancing the engineering properties of expansive soil. Several tests included liquid limits, plastic limits, free swell percentage, swelling pressure, and unconfined compressive strength were conducted on untreated and treated soils. The efficiency of adding 0, 2, 4, and 6 percentages of iron slag to the soil was investigated. The results of the natural and iron slag stabilized soils showed that iron slag has a notable effect on strength parameters and considerable improvement in plasticity and swelling properties. The addition of iron slag to the soil increased the unconfined compressive strength while reduced the swelling potential of soil. It is concluded that the utilization of iron slag to improve the properties of expansive soil is successful and useful

Iron-based composites have found a lot of industrial applications such as bearings, camshafts, connecting rods, pulleys, various valves, oil pump gears and many other applications in the automotive and other industries due to their low cost, availability, and high strength. The present study aims to prepare Fe-10 vol.% Cu - (0 – 5) wt.% nano Y2O3 composites by powder metallurgy technique and studying their physical and mechanical properties. The powders were mixed into ball mill for 30 minutes, followed by room temperature uniaxial compaction at 700 MPa for 3 minutes. The green specimens were sintered at 1000 oC for 1 hour. The results of the present study showed that nano yttrium oxide has significant effects on both physical and mechanical properties of Fe-10%Cu composite. The bulk density was increased by 0.92% and the true porosity was decreased by 6.4% on increasing the nano oxide content from 0% to 3% respectively. Vickers microhardness was increased by 5.9% on increasing Y2O3 up to 1% followed by gradual decrease on further increase above 1%. Wear rate was decreased by 21% on increasing the nano oxide content from 0% to 3%. On the other hand, the compressive strength was decreased by 47% on increasing Y2O3 up to 5%.

The goal of the present work is to study the performance of Ultra High Strength Con-crete (UHSC) beams in flexure under static and repeated loads. The main considered variables are the main reinforcement ratios which are (0.0129, 0.0204, and 0.0323), and the method of applying load. For each reinforcement ratio two beams were casted, one of them was tested under four points static load and the other one under repeated load up to failure. The behavioral characteristics of Ultra High Strength Concrete dominantly depends upon its load history, for this purpose experimental investigation of the behavior of (UHSC) beams under load history of repeated cycles is performed as well as that it is compared with the behavior under static load. The average cube compressive strength of the UHSC used in casting the beams was as high as (124 N/mm2). The load deflection curves, first cracks and failure loads, crack pattern, and concrete strain distribution over the depth of the beams were presented.

Shape Memory Alloys (SMAs) are a unique class of material that possesses unconventional properties such as the shape's memory effect, the high flexibility associated with damping capabilities, high wear resistance and fatigue. Given its use in a variety of technological applications, its studies have attracted increased interest in the community of scientists and researchers during the past decades.
The shape memory alloy (Cu 83%-Al 13%-Ni 4%) and the other alloy with adding the alloying elements (Mg) with content of (0.25, 0.5, 0.75, 1.0, 1.25) % as a volumetric ratio which was taken from the copper percentage were prepared by powder metallurgy, The powders were mixed using (V-type) powders mixer with mixing speed and time (20 rpm), (16 min) respectively then the samples were pressed by a two-way press (floating die) and pressing pressure (500 MPa) then the green samples where sintered by using vacuum furnace with using Argon gas medium at a temperature (900°C) for one hour and left in the oven to cool down to room temperature.
The results showed that both bulk density and apparent density compared to the base alloy increase by increasing the volumetric fraction of Mg by the ratios (5.49)% compared to the bulk density of the base alloy and by the ratios (1.51)% compared to the apparent density of the base alloy. accompanied by a decrease in the real and apparent porosity and water absorption, The results of the mechanical tests showed an increase in the hardness and diametrical compressive strength with the increase of volumetric fraction of (Mg) compared to the base alloy accompanied by a decrease in the rate of wear, The (XRD) test observes the composing phases (α(Cu4Al), β(Cu3Al), γ(Cu9Al44)) in addition to determining the transformation temperature from the Martensite to the Austenite by examining the (DSC) it was found that the Austenite initiation and finish (As), (Af) increased by adding the alloying elements (Mg).

This research involves investigating the toughness behavior of timber beams strengthened by jute fibers with various forms of strengthening. Ten timber specimens with dimensions (70×100×1000) mm are divided into four groups and loaded under a third point loading. The experimental program was carried out to investigate shear and flexural strengthening effects on toughness, toughness indices, ultimate loads, and the mid-span deflection of the tested beams. One beam as a control beam (un-strengthened beam), four specimens are wrapped in U technique in single and double layers along the whole length of the beam in full and strips wrapping technique, three specimens are wrapped in full technique along the whole length of the beam in full and strips wrapping technique, three timber specimens wrapped in flexural strengthening technique with two, four, and six layers of jute fibers. The results show that jute fibers strengthening increases the toughness ratios of timber beams by about (175%-320%), (190%-401%), and (106%-240%) for U, full, and flexural strengthening techniques, respectively, at the ultimate loads compared with the control beam. Furthermore, it is found that the highest toughness ratio is when the beam is wrapped in full strengthening technique.

The increasing costs of providing a residential unit is the main reason behind the residents well of minimizing the area of the plot which forms the big burden within the total cost. This change of the dimensions and area of the residential plot is expected to influence the functional plan of the residential unit . It is necessary to study this expected effect in creating some diversities on the functional pattern of the residential unit as a matter of fact ,which is known to be well-established with the bigger areas of the residential unit. These patterns could form new adaptations for living style towards the change in proportions and dimensions of the residential plot. Although some specialized studies have provided diverse functional patterns for functional organization following the variations of residential plot dimensions, the research points out that there is no full competence of the functional view created from the real effect of such variations, therefore the research problem is set to be" there is no clear theoretical imagination of the effects of minimizing the dimensions of residential plot on the spatial organization plans of actual residential units. The aim of the research is to limit the spatial organizations expected to emerge in actual residential units because of the variations of the dimensions of a residential plot and its ability to provide more economically appropriate models within the minimum areas the residential plot. The research hypothesizes that minimizing the width and the area of the residential plot leads to spatial organizations which form new adaptations of social needs for residents.. These six models represent the reliable areas and proportions adopted in dividing the city within applied partitions. The research the smaller residential plots, which were evaluated according to a scale to correspond with achieving the social needs within the concept of affordable residential unit.

Peace, mercy, and blessings of God be upon you
https://scholarlyoa.net
I looked at the site above, and on the allegations, he makes against Beall Jeffrey
I would like to clarify the following
1-It seems that the site is not official, and those who are responsible for it are unknown and they call themselves Friends of Open Access or a group of librarians did not say, publishers or university professors, they did not mention any name or institution sponsoring the site.
2-I read most of their claims about Beall Jaffrey's criteria, and it is incorrect. The criteria of Beall Jeffrey consist of about 40 items, and all of them are logical. And through it, the predatory journal is published quickly, without evaluation, and without classifying the article in international databases.
3-It focuses on the standard of publishing fees only, which is one of the criteria and does not mean that every journal that asks for fees is a predatory journal.
4-The site uses the same name as the Beall list but has a .net extension instead of .com, It violates publishing ethics and exploits the reputation of the well-known and well-known website.
5-Below are the links to Beall Jeffrey scientific pages, which shows the credibility of his articles published in reputable international journals. He has more than 1000 citations in the Scopus database, and more than 3000 total citations in all journals
-https://scholar.google.com.my/citations?hl=ar&user=EtHsEcMAAAAJ
-https://www.scopus.com/authid/detail.uri?authorId=8869689200
6-Beall's main website was suspended in 2017, there are many websites now that rely on Beall Jeffrey's criteria, but most of them are unofficial, and it may demand sums from journals to be removed from the list.
7-This site claims the existence of lawsuits against Bell Jefri and does not provide any evidence for that.