KUFA JOURNAL OF ENGINEERING

The aim of this study is investigating of effect of superplasicizer (SP) type and dosage at different levels of compressive strength on the fresh concrete workability and compressive strength development with age. The experimental program included preparation of 18 concrete mixes; these mixes were divided to three groups depending on compressive strength level, in each group, three different types of superplasticizer with two different dosages (0.5 and 1.0%) for each type of SP. The results showed that the type and dosage of SP have pronounced an effect on the development in early age especially. The early compressive strength development of concrete containing PCP and AP types was almost similar and faster than that of NF type. The estimated compressive strength in the early ages by EC2 and ACI 209 equation was lower than the experimental results.

In this paper, a new quadratic map (NQM) is proposed. Using this NQM, a chaotic signal can be generated directly by assuming an initial condition to NQM which can be converted into binary sequence to get a chaotic binary sequence. The chaotic binary sequences that were evolved in this system are typically broadband and noise-like sequence. However, because of these properties the chaotic binary sequence generating potentially provides an important class of signals which can be utilized in various communication systems. The results showed that the presented method generates a chaotic binary sequence with several advantages, such as the stability, broadband, difficult to predict, noise-like, and high randomness statistical properties.

This research aims to demonstrate a number of proposed barriers to implement the proactive building maintenance in Basra City in Iraq where the importance of maintenance needs a lot of clarification. In this study, the proposed barriers are identified from literature; their importance have been identified based on data collected from the questionnaire. A total of 27 barriers is identified and classified into six main areas which are technical, management and administration, financial, human behaviour and attitudes, spare parts, and lack of institutional and training facilities. This paper provides a review of the proposed barriers for implementing proactive building maintenance in Basra city. The identified barriers have been ranked against its importance and their effects on the implementation process.

Evapotranspiration is a main component of the water cycle and is important in crop growth. Monthly mean reference evapotranspiration (ETo) is estimated using gene expression programming (GEP) in Basrah City, south of Iraq. Various climatic data, such as air temperature, relative humidity, and wind speed are used as inputs of GEP model to estimate the values of reference evapotranspiration (ETo) given by the FAO-56 (Penman-Monteith equation). Nine input combinations tested with GEP are coded as model No. (1-9). Root relative squared error (RRSE) is taken as fitness function in each of GEP models. GEP models with three climatic input variables (temperature, relative humidity, and wind speed) take the highest level in the performance. The GEP technique was successfully employed to estimate ETo in the study area. The explicit formulas obtained can be used as powerful models for estimating the mean monthly ETo in the irrigation practices with limited climatic data.

Groundwater is an important natural resource necessary for drinking use for many societies all over the world, particularly in the rural areas. Due to water shortage problem in southern part of Iraq, the need arises to use the ground water especially in west of Basrah governorate, where it is considered as an important agricultural area in Iraq that supplies other areas of the country by main vegetable crops.
Twenty-seven wells were chosen to be study cases for hydrochemical sampling and analyzing to determine the physical and chemical properties then compared with the requirements of World Health Organization (WHO 1993), and different water classifications, to estimate the groundwater suitability for different purposes.
The collected samples in the field were analyzed for total dissolved solids (TDS), electrical conductivity (EC), pH, major cations like magnesium, calcium, sodium, potassium and anions like chloride, nitrate, carbonate, bicarbonate, and sulphate, in the laboratory.
Water Quality Index (WQI) was used to assess the suitability of groundwater from the study area for human consumption. It has been calculated for each sample taken from wells and were compared to the standard guideline values as recommended by the (WHO) for drinking and public health in order to have an indication of the present quality of groundwater. According to the overall evaluation of the sites, almost all the parameters analyzed are above the desirable limits of WHO, therefore it was concluded that the quality of groundwater from the studied areas were not suitable for domestic purposes and far from drinking water standards.

This study aims to apply Water Quality Index (WQI) to evaluate quality of groundwater samples collected from Basrah governorate south of Iraq. The samples were collected from (29) wells located in different districts of Basrah governorate (Safwan, Zubair, and Um-Qasr) during Summer Season of 2015. The groundwater samples were analyzed for pH, electrical conductivity, total dissolved solids and other major ions. For calculating WQI, eleven parameters; pH, EC, TDS, Total hardness as CaCO3, Calcium, Magnesium, Sulphate, Chloride, Nitrate, Sodium, and Potassium have been considered. The suitability of groundwater in the study area for human drinking purpose was achieved by WQI depending on guideline values of World Health Organization (WHO 2011) for chemical parameters. Then, the weights (Wi) were assigned to the parameters based on their influence on human health. The results showed that the (WQI) values for the groundwater of study area varied from poor to unsuitable for human drinking purpose.

The major reason for using asphalt mixture modifiers is to improve the performance of asphalt pavement to meet the requirement under prevailing stresses from traffic loading and environment effects and to reduce the pavement thickness.
Structural thickness design of asphalt pavement layers is a function of many factors; one of the most important of them is the elastic modulus (E) of the asphalt mix.
E values may be estimated directly in a laboratory by test, or indirectly by correlation with other tests like Marshall Stability. Additionally, E of hot mixture asphalt is used to estimate the layer relative strength coefficient (a) that is used to estimate the Structural Number parameter (SN), which allows for determining the required layer thickness.
The major objective of this research is to predate a statically model to estimate the effect of asphalt modification on the layer thickness. 75 specimens of control and modified HMA for surface are designed and tested according to Marshall Method with optimum asphalt cement content (4.8%) and different types and contents of available modifiers.

Nowadays, use of castellated steel beams (CSBs) has become very common because of their advantageous implementations in construction of buildings. Castellated Steel Beams (CSBs) are those members that are fabricated from standard hot rolled steel (HRS) I- sections by cutting along its web in "zigzag" pattern and thereafter rejoining the two halves on one another by welding together to form a castellated beam, so that generally the depth of  a section will be increased. This research analyses the experimental results of six specimens of castellated steel beams and compares with control beam (Parent section). The purpose of this study is to investigate the effect of hexagonal hole dimensions on the ultimate strength and stiffens response of the castellated steel beam. Also, the effect of number of holes on the behavior of the castellated steel beams that have the same span and ratio of expansion was investigated. All specimens of the castellated steel beam were fabricated from hot rolled steel section (IPE140) and were expanded to (1.56) times the parent section depth. From the test results, it is observed that best dimension of castellated steel beam was (span length to holes space ratio L/S = 8.0); hole depth to Castellated beam depth ratio is h/H=0.56, and hole space to the castellated beam depth ratio is S/H = 1.03. The ultimate strength of the castellated steel beam was increased about (50%) stronger than the original beam.

There are numbers of equations to evaluate the modulus of elasticity by current codes and researchers. This paper aims in developing an empirical equation to evaluate the modulus of elasticity for High Strength Concrete (HSC) considering the Iraqi aggregates used in producing the HSC. The analysis consider 78 tests from the available literature using Iraqi aggregates with a wide range of compressive strength of concrete from 41 to 83.3 MPa. The comparisons between the proposed equation here and the current codes ACI 318-14, EC2-02 and the equation by Noguchi show that for the ACI 318-14, there is an overestimation of 80% of the tests that are below it, while EC2 values are too conservative as they are below 78% of test results. The equation by Noguchi et al. showed better evaluations as it is very close to the proposed equation. More tests are required to finalize the developed equation, which cover all the parameters influecing modulus of elasticty in the produced HSC.

This paper presents the use of two different controllers in speed control of multi permanent magnet synchronous motors (PMSMs) master/slaves system. These controllers used to improve the performance of multi PMSMs drive system are conventional PI and PD-like fuzzy + I controllers. For PD-like fuzzy + I speed controller, simulation results clearly show that the response of the system is superior as compared to PI speed controller in terms of rise time, settling time, accuracy, and steady state error. The design and analysis of the system with both controllers have been simulated and studied using MATLAB/Simulink environment. Speed responses obtained under PI and PD-like fuzzy + I controllers are compared for a variety of load conditions.