Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 19, Issue 4

Volume 19, Issue 4, Summer and Autumn 2011, Page 1-122

Influence Of an Earthed Transformers On The Distance Protection Relay Measuring Accuracy For Double Transmission Lines

Dr. Abdul Ghani A. Abdul Ghafoor; Mr. Ahmed Ateya Al-Badrani

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 1-9
DOI: 10.33899/rengj.2011.26758


This paper investigates a study of the influence of an earthed transformer in a double circuit transmission lines have intermediate tapped to provide to loads on a measuring accuracy and performance of the conventional Distance Protection Relay (DPR) installed in this configuration when the ground faults occur beyond tee point. The protection of three-terminal lines is not as simple as that of two-terminal lines. They usually experience problems caused by the zero sequence current in-feed of an earthed transformer from the third terminal as well as mutual coupling due to this current. This study has been modeling and simulating by using (MatlabSimulink) program to analyze a steady state of ground fault on single circuit to calculate the DPR voltage, current and apparent impedance with various fault locations under operational status for the Iraqi North Regional Grids (INRG) 132 kV system. The paper results shows that current in-feed and mutual coupling by zero sequence of earthed transformer may cause the distance relay to seriously under-reach or Under Reach according to zero sequence current direction. The values of short circuit levels ratio of system have major effect in this problem, So an apparent impedance as seen by DPR and length of protective zone will change.

Modeling of Dynamic Processes of the Main Executive Mechanism of the Hot-crank Press

Mohammed Najeeb Abdullah; Victor Valerievich Telegin

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 1-10
DOI: 10.33899/rengj.2011.26787

The paper considers a dynamic model and its mathematical description of the central crank-slide mechanism of the hot-crank press. The peculiarity of the proposed model is ability to assess on its basis, the level of oscillatory processes at all levels of the mechanism: the crankshaft, connecting rod and the slider with calculation of the clearances in the joints of the crank-slider-crank and eccentric

Effect Of The Earthed Out of Service Transmission Lines On a Distance Measuring Relay Setting

Dr. Abdul Ghani A. Abdul Ghafoor; Mr. Ahmed Ateya Al-Badrani

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 10-19
DOI: 10.33899/rengj.2011.26759


This paper includes a study and analysis of an earthed out of service for one of double circuit transmission lines impact on a Distance Measuring Relay (DMR) setting due to zero sequence system mutual coupling. The protection in a remaining line measures the fault impedance correctly, except when the line that is not in service is earthed at both ends. In this case a DMR performance which installed in this configuration at the ground faults occur is much less reliable and accuracy to get an ideal tripping protected zone for its. This study has been Modeling and simulting by using (MatlabSimulink) program to analyze a steady state of ground fault on single circuit to calculate the DMR voltage,current and apparent impedance of sequences and system at various fault locations under operational status for the Iraqi North Regional Grids (INRG) 132Kv system. The paper results shows that mutual coupling by zero sequence current of earthed line may cause the DMR to seriously over-reach under different operational situations. The DMR first zone reach may extend to its second zone, So a DMR will give a trip signal for an external faults.


Hosam A. Daham

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 11-27
DOI: 10.33899/rengj.2011.26789

Concrete slabs with opening are usually designed with help of traditional rules of thumb proposed by building codes. Such methods, however, introduce limitations concerning size of openings and magnitude of applied loads. Furthermore, there is a lack of sufficient information and instructions are needed to design opening in slabs of different boundary conditions in existing concrete slabs. The aim of this research is to carry out finite element analyses by using the ANSYS 5.4 program with a non-linear concrete model satisfying complex support condition to predict the ultimate load for the different types of reinforced concrete slabs. The effects of openings for different types of boundary conditions were studied and show that the opening in slabs which having supported on four edges have little effects on slab. Boundary conditions also studied here which show the slabs fixed on two opposite edges at least have clearly behavior on slab compared with another boundary conditions. Opening also have a great effect on values and distribution of normal stresses in slabs especially at opening region.

Genetic Algorithm Based Small Distributed Generation Units Addition Technique To Reduce Real Power Losses

Saraa Esmaeel Khaleel

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 20-29
DOI: 10.33899/rengj.2011.26761


The increasing demand on installing small generating units had resulted in focusing on advanced concern of distributed generation (DG) units located at specific points of the electrical distribution grid as a mean of reduction in real power losses. This issue had been dealt with many techniques over the last decades.
This research paper is taking Genetic Algorithm technique into consideration as one of the most efficient tools in calculating the optimum value of these DG units added to the grid locations suffering from loading effect based voltage drop at the minimum real power loss. This research is also concerning the impact of increasing number of locations of DG units added to the grid the percentage of reduction in real power loss.

A study of Contaminate diffusion Through Layered Soil due to leachate migration From Landfill Site

A. A. AL-Daood

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 28-42
DOI: 10.33899/rengj.2011.26792

Contamination of soils and groundwater is considered as one of the major environmental problems. So, water and contaminate movement through soil especially in layered soil should be studied thoroughly. This research aims to study the contamination movement in a layered soil considering; water table fluctuation and applying the theories of transfer and diffusion in the unsaturated case. Numerical model with GEOSLOP software was used for simulating the movement of the contaminant through both saturated and unsaturated layered soils.
The study shows that various physical properties of soil layers has a serious impact on the movement of the contaminants, also it shows that the order of layers has a effective role in the extent of the movement and concentration of leachate in the area surrounding the location of landfills in the case of unsaturated soil, while changes in the level of groundwater don't make any change that can be mentioned with the number and order of layers but leads to a small changes in concentration of leachate. Whereas steady saturated soil conditions did not affect by the order and number of layers on the movement of leachate, but it is effected by the change in ground water level ,the change including the concentration and extend of the contaminate movement.

Effect of Partial Replacement of Fine Aggregate on Some Engineering Properties of Concrete

Zeena Adel Mohammed

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 30-39
DOI: 10.33899/rengj.2011.26763

Recently, interest set out for obtaining new recourses for natural aggregate ate used in concrete mixes. Attempts are also intensified to make use of the accumulation of certain types of construction and building residues such as bricks' fragments or the filler that results from the cutting of limestone and others to be used in concrete production as a partial replacement material of some of its components on the one hand and in order to achieve an economical benefit while executing the constructional projects on the other.
The research aims at studying the effect of using porcelain crushed filler as a partial replacement material for the fine aggregate in the concrete mix and the effect of this on the concrete properties. In this research, the porcelain crushed filler was added in ( 0, 10, 20,30, 40)% replaced by the weight of the fine aggregate.
Findings obtained have shown that the use of the porcelain crushed filler has affected the properties of concrete as it has caused a drop in the concrete density up to 6.07% at a replacement percentage of 40% and reducing its capacity of water absorption down to 17% at the same percentage. Findings have also shown the positive effect of the porcelain crushed filler on the compressive and tensile strengths with an increase reaching 18% at a replacement percentage 20% compared to the normal concrete.

Effect of Spans Length on Structural Design of Multi story Buildings

Tarek Edrees Saaed; Nuha Hemedy Al-Jubory

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 40-62
DOI: 10.33899/rengj.2011.26769

The aim of this research is to obtain the optimum spacing between columns in both directions for multi story buildings through the optimization of reinforced concrete required to construct them. This will help the designer in determining the economic spacing in the preliminary design stage, to predict the cross section sizes of members for these spans and to determine the most influenced structural members. A four story (ground + 3 floors ) virtual reinforced concrete building was analyzed and designed for three cases of columns spacing ( 3.0 m , 6.0 m , 9.0 m ) using reinforced concrete frame structures for the same working load conditions. A detailed estimation and comparison for reinforced concrete quantities was carried out for the structural members and the average per square meter was calculated.
The results showed that the foundation was the most influenced members due to increase in the span of columns, 3.72 m was the optimum spacing concerning the quantity of Concrete required for construction (0.965 m3/m2) while the span of 4.23 m was the optimum span for reinforcing steel (86.64 kg/m2).

Mathematical Model for Calculating Oxygen Mass Transfer Coefficient in Diffused Air Systems

Kossay K. Al-Ahmady

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 43-54
DOI: 10.33899/rengj.2011.26795

The key element in developing an analytical or mathematical procedure is to determine the main factors that possess potential importance in oxygen transfer process. In this paper, the factors that affect the oxygen mass transfer coefficient (KLa) in activated sludge units are determined. A dimensional analysis procedure is adopted to develop a mathematical model, which can be used for calculating these factors. A very high accurate model with a correlation factor of (98.889 %) is obtained from this analysis. The solution of the model shows that: The main dimensionless groups which controlling the oxygen mass transfer in this units are: Reynolds number, Froude number, the ratio of bubbles diameter to length of its bath in water, the ratio of water depth in the tank to tank length, and the ratio of diffusers area to tank area. Each of the Reynolds number and the ratio of area of diffusers to the area of tank have positive effect on the oxygen mass transfer coefficient. Increasing any of airflow rates, the area of diffusers coverage in the tank and the length of the path of bubbles in water significantly increase the oxygen mass flow rate while this ability can also be increased by decreasing the diameter of bubbles in the system.

FPGA Implementation of Multiplierless DCT/IDCT Chip

Dr. Ahlam Fadhil Mahmood; Abdulkreem Mohameed Salih

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 55-67
DOI: 10.33899/rengj.2011.26797

The advance of mobile electronics technology has produced handheld appliances allowing both wireless voice and data communications. One of the most important operations in the realm of digital signal and image processing is the 2-D Discrete Cosine Transform. This paper presents a multiplierless two dimensional Discrete Cosine Transform/Inverse Discrete Cosine Transform (DCT/IDCT) based on the transpose method. In this method the 2-D DCT is obtained by taking two 1-D DCTs in series. The input data is first divided into NxN blocks and the row-wise 1-D DCT of each block is taken, the intermediate transposition is then determined and a column-wise 1-D DCT is ascertained which gives the 2-D DCT of the data. The hardware implementation is parallel, pipelined and decomposed the coefficients matrix into four power of two term(i.e:16 ) to perform shift and add operations instead of multipliers(i.e 16); it costs only 1,443 slice , and runs at maximum frequency of 82.8 MHz with a very high process throughput of 991.2 Megabits/sec when synthesized onto Spartan3-E XC3S500 FPGA device. The proposed 2-D DCT/IDCT design achieving the most demanding real-time requirements of CODEC standardized frame resolutions and rates.

A Study of Factors Affecting Drain Spacing Calculated with Different Methods

Dr.Abdul Sattar Aldabagh; Entesar M.Ghazal; Ali M.Yaseen

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 63-77
DOI: 10.33899/rengj.2011.26777

A computer model is developed to find the drain spacing using dynamic equilibrium and peak irrigation period and steady state concepts. Then sensitivity analysis is done to study the impact of drain depth, soil and crop type, salinity of irrigation water and irrigation scheduling on the drain spacing calculated with the dynamic equilibrium .Three different soil textures and three crops, wheat, potato, corn are chosen with surface irrigation.
The drain spacing is influenced by the crop and soil type. In general, the drain spacing with the dynamic equilibrium is higher than that of the peak irrigation period and, less than the steady state concept. The most influential factor on the drain spacing, is deep percolation losses for each irrigation, followed by hydraulic conductivity of soil, depth of impermeable layer, permissible water table depth, drain depth and salinity of irrigation water. The drain spacing for wheat is more sensitive to the change in drain depth, permissible water table depth, depth of impermeable layer, salinity of irrigation water and hydraulic conductivity of the soil, while that for potato is more sensitive to the change in deep percolation losses .

Design and FPGA Implementation of Dual Scan two Dimensional Discrete Wavelet transforms

Zahraa Talal Abed Al-Mokhtar

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 68-78
DOI: 10.33899/rengj.2011.26800

In this paper, hardware architectures for two dimensional discrete wavelet transform (2-D DWT) are examined, the 4-input/4-output Dual Scan architecture for one-level DWT is presented, then by using the pipelined architecture and parallel method, the one-level architecture is developed to perform a complete dyadic decomposition of NXN image in multi-level 2-D DWT. After that the internal memory sizes that are needed to design the proposed architectures and the proper fixed point word length are determined. The proposed architectures are down loaded in to FPGA board (Spartan-3E) to calculate the die area and the critical path of these architectures. The main advantage of Dual Scan method is high reduction in the time delay to perform the architecture.

Maximizing the Benefit from Rain and Supplemental Irrigation Water in Mosul Area

Dr. N. M. Jajo; Dr. E. Hazem; R.M. Hameed

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 78-88
DOI: 10.33899/rengj.2011.26779


The daily rainfall (amount and distribution) for 28 years at Mosul area along the growing season of wheat crop are studied . The objective is to determine the onset rainfall for rainfed cropping of wheat..
Two computer simulation models were formulated, tested and then used in the study. The first model was to estimate the onset rainfall (date). The output of this model for all years is used as an input for a second simulation model that monitors the daily water budget in the entire root zone depth of a growing season of a wheat crop in order to estimate the evapotranspiration and variation of water content in the soil profile over the season along with the date and amount of one , two , or three supplemental irrigations during the season. The goal of these irrigations is to convert certain failure years to successful year for rainfed cropped wheat.
The study showed that adding one supplemental irrigation (75 mm) around the end of the rainy season increased the yield ratio by 9% while applying two supplemental irrigations has increased the yield ratio by 30% and converted four failure years to successful ones. It is also shown that the return from supplemental irrigation is economically feasible in all of the studied cases .

Simulation and Design of a Finned tube air cooled condenser used in absorption refrigeration systems

Firas Salah Yahia Al-Khayatt

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 89-98
DOI: 10.33899/rengj.2011.26780


Absorption refrigeration systems(ARS) reduce the consumed energy comparing with the compression refrigeration systems. The (ARS) need the thermal energy for its work which can be provided from alternate and different sources such as solar energy, waste heat from industrial processes or from other resources. So one must focus on the small (ARS) for the purposes of air conditioning for houses and small buildings which use air-cooled condensers instead of water cooled condensers to eliminating the cooling tower. Thus, in this study a new model of an air cooled condenser is suggested which consisting of cylindrical tubes in staggered triangular arrangement with radial fins of rectangular profile. In this study, a model is proposed using the equations of heat transfer and considering factors affecting the performance of the condenser such as number and dimension of tubes, transverse and longitudinal distances between tubes, number of fins, temperature of cooling air and temperature of the condenser. Also the study will include the design correlations for the amount of rejected heat from a condenser to an atmosphere. This model can be used in (ARS) working with (Water-Lithium Bromide) or (Ammonia-Water).

Human Factors of Green Architecture Green Building of Nikken Sekkei

Ghada Mohammed Yonis

Al-Rafidain Engineering Journal (AREJ), 2011, Volume 19, Issue 4, Pages 99-122
DOI: 10.33899/rengj.2011.26784

Human factors is the most important components of Green Architecture besides the main approach of energy consumption and preservation . That factors are reflected by introduce comfort and healthy spaces , Which suitable for human occupation both physical and psychological. The article concern the relationships of Green Architecture with nature first: as a crucial natural system , second as a natural appearance or views . The work study is concern the style of Green building of Japan architect Nikken Sekkei , Who used the concepts of Japan Traditional Architecture with new technical approach . The conclusion is that the suitable sustainable technical in Green Architecture is by unit and immerge the natural element ( sun light and heat- wind flow- earth temperature)as new tools in steps of design process .
Keywords: green architecture , comfort ,healthy