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joe-221
Numerical Investigation Using Harmonic and Transient Analysis To Rotor Dynamics
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The rotor dynamics generally deals with vibration of rotating structures. For designing rotors of a high speeds, basically its important to take into account the rotor dynamics characteristics. The modeling features for rotor and bearings support flexibility are described in this paper, by taking these characteristics of rotor dynamics features into standard Finite Element Approach (FEA) model. Transient and harmonic analysis procedures have been found by ANSYS, the idea has been presented to deal with critical speed calculation. This papers shows how elements BEAM188 and COMBI214 are used to represent the shaft and bearings, the dynamic stiffness and damping coefficients of journal bearings as a matrices have been found with the variation of rotation speed of the rotor which are vary with eccentricity of journal with bearings and this eccentricity is a function of Sommerfeld number, the first critical speed analysis has been done from Campbell diagram, the critical speed it is the speed at which resonance case happen, the unbalance response analysis has been done with changing the unbalance mass then finding the maximum response of the rotor for each unbalance mass case, by Campbell diagram plot recognizing the stability of the system and find the line of un stability, above and down this line the system is stable and if speed lies on this line the system is unstable, the main reason of analysis of rotor dynamics is to help Engineers to characterize the lateral dynamics characteristics of a given design with Campbell diagram plot, can find the critical speed, the unbalance response and the system stability .

 

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Publication Date
Sat Jan 19 2019
Journal Name
Iraqi Journal Of Agricultural Sciences
USING PROBABILITY REGRESSION MODELS TO MEASURING MANAGEMENT EFFICIENCY FOR BROILER PROJECTS
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The efficiency of management is determining factor for the success or failure of agricultural projects generally and Livestock particularly achieving its objectives. Therefore, this research came to diagnose the most important variables that determine the efficiency of management using the probability regression models to measure the probability of management efficient of broilers production projects using  random sample included (60) broilers projects represented 11.6% of Baghdad province (research community) in 2016. After estimating the relationship between the management efficiency (descriptive dependent variable) and the independent variables affecting it (age, educational level, production index (PI), experience). The results

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Publication Date
Fri Mar 01 2024
Journal Name
Heliyon
Using unsafe traditional practices by Iraqi mothers to treat newborns' problems
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Publication Date
Thu Jun 20 2019
Journal Name
Baghdad Science Journal
Using Backpropagation to Predict Drought Factor in Keetch-Byram Drought Index
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Forest fires continue to rise during the dry season and they are difficult to stop. In this case, high temperatures in the dry season can cause an increase in drought index that could potentially burn the forest every time. Thus, the government should conduct surveillance throughout the dry season. Continuous surveillance without the focus on a particular time becomes ineffective and inefficient because of preventive measures carried out without the knowledge of potential fire risk. Based on the Keetch-Byram Drought Index (KBDI), formulation of Drought Factor is used just for calculating the drought today based on current weather conditions, and yesterday's drought index. However, to find out the factors of drought a day after, the data

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Using Markov chains to forecast the exports of Iraqi crude oil
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       In this paper, the topic of forecasting the changes in the value of Iraqi crude oil exports for the period from 2019 to 2025, using the Markov transitional series based on the data of the time series for the period from January 2011 to November 2018, is real data obtained from the published data of the Central Agency Of the Iraqi statistics and the Iraqi Ministry of Oil that the results reached indicate stability in the value of crude oil exports according to the data analyzed and listed in the annex to the research.

Keywords: Using Markov chains

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Publication Date
Mon Jan 01 2024
Journal Name
Journal Of Surgery
Evaluation of using double Teostrut graft to control naral tip projection
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Abstract Background: Dne of the key component of nasal tipplasty is effecter control of naral tip projection. Several cartilage grafts have been decreased for this purpose each had its own advantage and disadvantage. Aim: To evaluate using of double teostrut graft for controlling of tip projection. Patients and Methods: A total number of 170 patients were subjected to primary and secondary rhino plaster between January 2020 to January 2023. Those patients had double Teostrut banner graft for support of their nasal tip and maintaining tip projection after operation. Results: The follow period was ranging between 6-12 months. The shape of the nose was evaluating by patents vernal analogues scale. The average score for patients satisfaction wa

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Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Economics And Administrative Sciences
Using Statistical Methods to Increase the Contrast Level in Digital Images
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This research deals with the use of a number of statistical methods, such as the kernel method, watershed, histogram, and cubic spline, to improve the contrast of digital images. The results obtained according to the RSME and NCC standards have proven that the spline method is the most accurate in the results compared to other statistical methods.

 

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Publication Date
Tue Aug 01 2023
Journal Name
Baghdad Science Journal
Using microalga Coelastrella sp. to remove some nutrients from wastewater invitro
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Microalgae have been increasingly used for wastewater treatment due to their capacity to assimilate nutrients. Samples of wastewater were taken from the Erbil wastewater channel near Dhahibha village in northern Iraq. The microalga Coelastrella sp. was used in three doses (0.2, 1, and 2g. l-1) in this experiment for 21 days, samples were periodically (every 3 days) analyzed for physicochemical parameters such as pH, EC, Phosphate, Nitrate, and BOD5, in addition to, Chlorophyll a concentration. Results showed that the highest dose 2g.l-1 was the most effective dose for removing nutrients, confirmed by significant differences (p≤0.05) between all doses. The highest removal percentage was

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Publication Date
Wed May 26 2021
Journal Name
Communications In Mathematical Biology And Neuroscience
Modelling and stability analysis of the competitional ecological model with harvesting
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The interplay of predation, competition between species and harvesting is one of the most critical aspects of the environment. This paper involves exploring the dynamics of four species' interactions. The system includes two competitive prey and two predators; the first prey is preyed on by the first predator, with the former representing an additional food source for the latter. While the second prey is not exposed to predation but rather is exposed to the harvest. The existence of possible equilibria is found. Conditions of local and global stability for the equilibria are derived. To corroborate our findings, we constructed time series to illustrate the existence and the stability of equilibria numerically by varying the different values

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
The influence of prey density on the numerical response of Chrysoperla mutata MacLachlan
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The numerical response of Chrysoperla mutata MacLachlan was achieved by exposing the larvae of the predators to various densities of dubas nymphs Ommatissus lybicus DeBerg. Survival rate of predators’ larvae and adults emergence increased with increasing consumption . Repriductive response of predator was highly correlated with the amount of food consumed (+0.996).

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Publication Date
Wed Mar 15 2023
Journal Name
Journal Of Petroleum Research And Studies
A Numerical Study of Tertiary Oil Recovery by Injection of Low-Salinity Water
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The injection of Low Salinity Water (LSWI) as an Enhanced Oil Recovery (EOR) method has recently attracted a lot of attention. Extensive research has been conducted to investigate and identify the positive effects of LSWI on oil recovery. In order to demonstrate the impact of introducing low salinity water into a reservoir, simulations on the ECLIPSE 100 simulator are being done in this work. To simulate an actual reservoir, an easy static model was made. In order to replicate the effects of injecting low salinity water and normal salinity, or seawater, the reservoir is three-phase with oil, gas, and water. It has one injector and one producer. Five cases were suggested to investigate the effect of low salinity water injection with differen

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