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Comparative Study of Performance and Emission Characteristics between Spark Ignition Engine and Homogeneous Charge Compression Ignition Engine (HCCI)
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Many researchers consider Homogeneous Charge Compression Ignition (HCCI) engine mode as a promising alternative to combustion in Spark Ignition and Compression Ignition Engines. The HCCI engine runs on lean mixtures of fuel and air, and the combustion is produced from the fuel autoignition instead of ignited by a spark. This combustion mode was investigated in this paper. A variable compression ratio, spark ignition engine type TD110 was used in the experiments. The tested fuel was Iraqi conventional gasoline (ON=82).

The results showed that HCCI engine can run in very lean equivalence ratios. The brake specific fuel consumption was reduced about 28% compared with a spark ignition engine. The experimental tests showed that the emissions concentrations were reduced by 91.27% for NOx, 85.99% for CO, 78.91% for CO2, and 83.56% for unburned hydrocarbons compared to the SI engine. HCCI engine produced little noise with about 26.68% less than SI engine.

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Publication Date
Sun Feb 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
effect work stress in performance of employees In The general company for vegetable oil industry
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This research theme of the pressures of work , which is one of the important topics in order to recognize the reality of( influencing the pressures of work in the performance of employees in the General Company for Vegetable Oil Industry in Baghdad )through the statement of the existence of the correlation and influence whether or not the statement of the strength of this relationship and its impact in the case of its existence has been provided as part of my Search for variables and their removal in front of the Sub- scientific aspect has been the distribution of the questionnaire on a sample of( 62) people working in the company Mint distributors on several sections where.

Formed resolution of two sets

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
THEORETICAL AND EXPERIMENTAL STUDY ON THERMAL PERFORMANCE OF CLOSED WET COOLING TOWER
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Thermal performance of closed wet cooling tower has been investigated experimentally and theoretically
in this work. The theoretical model based on heat and mass transfer equations and heat and mass transfer balance equations which are established for steady state case. A new small indirect cooling tower was used for conducting experiments. The cooling capacity of cooling tower is 1 kW for an inlet water temperature of 38oC, a water mass velocity 2.3 kg/m2.s and an air wet bulb temperature of 26oC. This study investigates the relationship between saturation efficiency, cooling capacity and coefficient of performance of closed wet cooling tower versus different operating parameters such wet-bulb temperature, variable air-spray water fl

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Publication Date
Mon Oct 22 2018
Journal Name
Journal Of Economics And Administrative Sciences
Dimensions of binding and non-binding social responsibility and its relationship to organizational performance / Field Study in telecommunications companies in the Republic of yemen
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The study aims at measuring the dimensions of binding and non-binding social responsibility and its relation to the organizational performance in telecommunication companies in the Republic of Yemen using analytical descriptive approach and questionnaire as a main tool for data collection and comprehensive inventory method.

It has been found  that there is a positive effect and significant moral relation between social responsibility with its binding and non-binding dimensions  and the organizational performance of telecommunication companies in the Republic of Yemen at a level of significance below (0.05). It has also been found that the correlation between the non-binding social responsibilit

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Publication Date
Sat Dec 01 2012
Journal Name
Iraqi Journal Of Physics
Wavelet compression for remotely sensed images
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Image compression is very important in reducing the costs of data storage transmission in relatively slow channels. Wavelet transform has received significant attention because their multiresolution decomposition that allows efficient image analysis. This paper attempts to give an understanding of the wavelet transform using two more popular examples for wavelet transform, Haar and Daubechies techniques, and make compression between their effects on the image compression.

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Compare between simex and Quassi-likelihood methods in estimation of regression function in the presence of measurement error
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       In recent years, the attention of researchers has increased of semi-parametric regression models, because it is possible to integrate the parametric and non-parametric regression models in one and then form a regression model has the potential to deal with the cruse of dimensionality in non-parametric models that occurs through the increasing of explanatory variables. Involved in the analysis and then decreasing the accuracy of the estimation. As well as the privilege of this type of model with flexibility in the application field compared to the parametric models which comply with certain conditions such as knowledge of the distribution of errors or the parametric models may

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Publication Date
Thu Dec 31 2020
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
THE IMPACT OF ETHICAL LEADERSHIP BEHAVIOR IN UNIVERSITY PERFORMANCE- STUDY EXPLORATORY AT SUMER UNIVERSITY: THE IMPACT OF ETHICAL LEADERSHIP BEHAVIOR IN UNIVERSITY PERFORMANCE- STUDY EXPLORATORY AT SUMER UNIVERSITY
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The aim of the study was to find out the correlations and impact between the variable of ethical leadership behavior and university performance at Sumer University. Use the descriptive analytical method by adopting the questionnaire tool to collect data. The questionnaire was distributed electronically to 113 teachers at Sumer University and the response was from 105 teachers. The research results showed that there is a correlation and effect relationship between the search variables. In addition, the responding university does not have ethically defined standards in terms of performance of the work of the cadres working there. Finally, the research presented a set of recommendations aimed at tackling problems in the ethical lead

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Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
comparison between the methods estimate nonparametric and semiparametric transfer function model in time series the Using simulation
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 The transfer function model the basic concepts in the time series. This model is used in the case of multivariate time series. As for the design of this model, it depends on the available data in the time series and other information in the series so when the representation of the transfer function model depends on the representation of the data In this research, the transfer function has been estimated using the style nonparametric represented in two method  local linear regression and cubic smoothing spline method The method of semi-parametric represented use semiparametric single index model, With four proposals, , That the goal of this research is comparing the capabilities of the above mentioned m

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Publication Date
Thu Dec 01 2022
Journal Name
Baghdad Science Journal
Comparison between RSA and CAST-128 with Adaptive Key for Video Frames Encryption with Highest Average Entropy
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Encryption of data is translating data to another shape or symbol which enables people only with an access to the secret key or a password that can read it. The data which are encrypted are generally referred to as cipher text, while data which are unencrypted are known plain text. Entropy can be used as a measure which gives the number of bits that are needed for coding the data of an image. As the values of pixel within an image are dispensed through further gray-levels, the entropy increases. The aim of this research is to compare between CAST-128 with proposed adaptive key and RSA encryption methods for video frames to determine the more accurate method with highest entropy. The first method is achieved by applying the "CAST-128" and

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Emission Spectra for the Isotopic Molecule Lithium Hydride
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A study of the emission spectra of isotopic for electronic states has been carried out. The energies of the vibration levels ( =0,1,..25) and the values of spectral lines R(J) and P(J) versus rotational quantum number (J=0,1..25). It was found that were an increase of the value of R(J) with the increase of the values of J was found while the value of P(J) decreases with decreasing of the values of J . It was found that corresponding to R(J) and P(J) the spectral line R(J) increases when the values of m increased.

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Publication Date
Mon Dec 30 2019
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Comparative Study of Pressure Losses and Hole Cleaning Efficiency of Water and Polymer solutions in Horizontal Wells
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The main objective of this study is to experimentally investigate the effect of the CMC polymeric drag reducer on the pressure drop occurred along the annulus of the wellbore in drilling operation and investigate the optimum polymer concentration that give the minimum pressure drop. A flow loop was designed for this purpose consist from 14 m long with transparent test section and differential pressure transmitter that allows to sense and measure the pressure losses along the test section. The results from the experimental work show that increasing in polymer concentration help to reduce the pressure drop in annulus and the optimum polymer concentration with the maximum drag reducing is 0.8 kg/m3. Also increasing in flow rate a

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