AL-Rafidain Engineering Journal (AREJ)

This paper is concerned with the Non-linear behavior of reinforced concrete slabs at
high temperature at service loads. Layered degenerated shell element is used to predict the
complex feature of structural behavior at high – temperature condition, such as thermal
expansion, cracking, crushing, yielding and changing of materials properties with
temperature. In the development of F.E model, the geometrical nonlinearity is considered, the
layered element are modified to allow for temperature distribution and change of materials
property through thickness .Predictions from this analysis are compared to the available
experimental results and good agreements obtained.

The aim of this research is to study the maturity of concrete for predicting in-situ
compressive strength for any concrete mixture in any structural work based on the laboratory
testing results of several concrete specimens, then finding a relationship between compressive
strength-maturity mathematical models that can be used for predicting the compressive
strength. Three type of mixes were used; first mix contains ordinary Portland cement (O.P.C),
second mix contains sulphate resisting Portland cement (S.R.P.C), third mix contains ordinary
Portland cement with an admixture (caco3) of (15%) replacement of cement weight.
Compressive strength tests at different ages (3,7,14,28) days and different
temperatures(27±2°C) (80.6±2°F)&(34±2°C) (93.20±2°F) and curing conditions of (moist
and air cured). The maturity was found for concrete samples using the Plowman technique
with the datum temperature at (-11.6°C) (11°F),the actual compressive strength values found
from laboratory testing were compared with the predicted compressive strength values from
Plowman equation to estimate the margin of the errors involved, the error was found to be
reasonable especially for the moist cured samples.

Studying the effects of the static and dynamic loads on structures is very essential,
especially in zones where the structures are exposed to severe earthquakes. In the present
study a finite element program is developed for static and dynamic analysis of reinforced
concrete plane frames. The main concern is to study the effects of infilled panels on the
behavior of this type of structure. One dimensional Beam-Column Elements are used to
represent the frame members and Lumped Plasticity Model is used to model the nonlinearity
of these elements. Modified Four-node isoparametric plane stress elements with 3-DOF per
node, are used to represent infilled panels. Connection between infill element and frame is
either assumed to be perfect or by linkage elements which allow separation between the two
types of elements. Two programs are developed one for the static and the other for the
dynamic analysis and the validity of the developed programs have been checked and the
predicted results indicated a good agreement with the published experimental and theoretical
results.

T h e present research concentrated on the evaluation of Khosar River water quality
which disposes its waste directly into Tigris River within the city of Mosul,It represents a
mixture of domestic and hospital wastes . The results showed ancrease in the phosphate
concentration of the Khosar river water increased(5) times, the biological and chemical
oxygen demand increase by (1.5, 1.48) times respectively compared to the Iraqi standard
No. (25-B1) in (1967) of the conservation of water resources. According to the organic load
, the Khosar river wastes were classified as weak since the biological oxygen demand
(BOD5) was (60)mg/l as an average. It is noticed that a biological pollution indicators do
exist in the Tigers river its effluent at a distance exceeding (600)m in the left bank of the
river. Despite that, the Tigris river water remained within the Iraqi standards No. (25-A1) in
(1967) for conservation of water resources after its combination to Khosar river effluent due
to the facts of dilution and diffussion.
T his study indicated that the wastewater of Khosar is a domestic waste, and that the
value of the removal constant rate was(k) about (0.1315/day) which is within the range of
domestic waste of (0.05-0.3)/day .Using the batch system for the aeration of waste at
intervals of (1-48) hrs, it was found that the optimum removal efficiency of organic matter
was at an aeration interval of (26) hrs.

This research includes studying the effect of using natural coagulant aid "Walnut Coat" with
alum and synthetic polyelectrolyte with alum also on turbidity removal compared with alum alone.
A set of jar test was conducted on raw water of different turbidities (5, 10, 20, 40, 50, 80 and 100)
NTU using different doses of coagulants and coagulant aids. Final turbidity, pH., were measured
after settling. The obtained results indicated that the use of walnut coat with alum was effective in
the removal of turbidities of (20, 40) NTU compared with alum alone. While the addition of
polyelectrolyte with alum was found to be more effective for higher turbidities (50, 80, 100) NTU.
Additionally, the average reduction in pH-value was more using walnut coat than that of using alum
alone. Furthermore, walnut coat led to the formation of large, clear and easily settled flocs within
the first 5 minutes of slow mixing, while same flocs appears at the end of 30 minutes of slow
mixing with alum and polyelectrolyte as flocculant aid. Better sludge characteristics were obtained
with walnut coat as flocculant aid, with low water content and high density which can be easily
dried and disposed.

T h e experimental investigation carried out is to study the effect of curing
methods on the compressive, splitting, and flexural strengths (modulus of rupture) of
self compacting concrete in comparison to those of normal concrete.
T h e self compacting concrete consisted of Portland cement (P.C) limestone
powder (L.S) (L.S 8% / 92% P.C),sand, gravel and super-plasticizer. The specimens
were cured in the air and water, for the period of 7, 14, and 28 days. Three
specimens were tested for each point of each property. The results showed that the
water cured specimens gave highest compressive strength, splitting tensile strength
and flexural strength than specimens cured by air about 11%, 10% and 11% for self
compacting concrete at 28 days respectively.
T h e results also show that self compacting concrete gave high early strength
i.e. strength before 28-days.
T he failed specimens indicated that there was no segregation and a good bond
between aggregate and matrix.

S hape is presented as one of the architectural design's basic elements, which together
determine the ultimate appearance and content of the architectural form. It is the property
which determine the appearance, and for which the design and composition of form are
related throughout shape types which might be geometric or organic or even the two as well.
The importance of this property has emerged, especially, when the architecture of 211st
century in its beginnings concentrated on the principle of "the power throughout shape" by
using organic forms which have complicated and daring shapes. The paper discusses the
importance of this property and its creation in the designs, in order to explore the particular
problem which has been represented as (lack of clarity in description shape's element and
paradigms of creating its types in different architectural trends).
T hus the objectives of the paper has been formed by building theoretical framework
consisting of two main items of detailed theoretical field as the following: (paradigms of
identification of shape and paradigms of creating shape types) which specifies shape element,
firstly, then the application of the paradigms of creating shape types on one of the important
trends throughout architectural history, which is Wright's organic trend, secondly, finally,
concluding paradigms of creating form's shape in Wright's architecture, thirdly.
Conclusions have been declared Wright's concentration in creating shapes of its projects
on a conceptual philosophy based on the integration between the shape and the main function
of the building through selected place and time, by using selected design and compositional
properties in relation to nature as a source of inspiration of form's shape.

The asphalt content of an asphalt mixture, as binder, is an important physical
characteristics and influences the performance life of flexible pavements. Traditionally, in
Iraq the asphalt content has been measured in laboratory by extraction from the mixture with
chemical solvents. Recently, a new technology, known as the ignition method, has been
developed to eliminate the need for these harmful solvents and to make the laboratory more
safer. The main objective of this work was to evaluate and use the ignition test method to
determine asphalt content and aggregate gradation in hot mix asphalt mixtures. An extensive
laboratory work was conducted to meet this objective, which involving more than 300
samples of asphalt mixture, with five asphalt contents and two types of aggregate of three
types of gradation, were prepared and tested using ignition and extraction methods.
D a ta from ten laboratories was analyzed and used to determine the accuracy and
precision of this test method. The study results and statistical analysis have show that the ignition method can be used to accurately and quickly determine the asphalt content and aggregate gradation of asphalt mixtures with same, if not greater, precision than the extraction method.

The chemical characteristics of ground water samples in Bartelah and Ain Safra
catchments area NE of Mosul city have been studied through chemical analysis of (11) water
samples to evaluate the quality of ground water to determine its suitability for domestic and
agricultural uses. Physical and chemical parameters of ground water samples such as Ca, Na,
Mg, K, HCO3, SO4, Cl, NO3, Ec, TDS, pH, and (TH) were determined. Ion concentration is
found to be directly related to environmental and hydrogeologic features.
Chemical parameters were analyzed graphically by means of contour maps for Ca, Na,
HCO3, SO4, Cl and Ec to illustrate the spatial distribution of chemical constituents of the
ground water.
Piper diagram is also used to show the suitability, type and the geochemical evolution of
ground water. Richard and Wilcox classifications are also used to show the suitability of
ground water for irrigation. that most ground water samples falls in the field of doubtful to
unsuitable for irrigation except samples 7, 8 and 9 which they are fell in the field of good to
permissible for irrigation.
Interpretation of analytical data shows that mixed cations-SO4 type, mixed cation-
HCO3 type and mixed Ca-Mg-Cl type are the dominant chemical faces. Ground water is
generally hard, fresh to saline and low alkaline in nature

Quality of Service (QoS) mechanisms provide the necessary level of services
(bandwidth and delay) to any application in order to maintain an expected quality level. This
paper studies the effect of adopting QoS on the performance of (real time) system like video
conferencing. A simulation model of the real time network is built using OPNET package.
The various parameters affecting the system performance are determined and different
solutions to enhance the system performance are suggested .A modified switch architecture is
proposed to enhance the real time performance of the system and to modify its quality of
service capability .The modification includes adding Etherchannel unit which can classify
data into real time or non-real time data and direct each data packet to the appropriate channel
.The architecture of the Etherchannel unit is described by VHDL programming and built on
FPGA chip .Accordingly , the modified switch is found to need only extra seven clock pulses
to classify each data packet .

A universal distance relay that has merits over conventional relays is designed. This
relay has the ability to adapt more than one working characteristic by using an artificial neural
networks technique(ANN)of the type Modified Multi-Layer Perceptron (MMLP) which uses
additional nodes at the input layer to realize an adaptation through the required modifications
on the distance relay characteristics. The inputs of the added nodes referred to the factors that
affect the distance relay characteristic such as: fault resistance, power transfer, mutual
inductance and locations of feeding sources in the system. A Matlab computer programming
was used to simulate different power systems of (400, 132) KV to obtain impedance
characteristic data, needed to train and test the ANN. A laboratory power system ( 220V) has
been operated as a computer simulation model and practically under the same conditions. The
designed universal relay gives good performance when tested on a computer model of this
system .The small difference between the practical results and that of simulation, encourage
the use of designed relay to protect transmission lines in reality.

This paper reviews in brief the principle of distributed amplifier with its classical
structure. Alternation to the basic design including the use of ????-filtering sections instead of Tsections
in gate and drain lines is proposed. The new design method has the advantages of
much gain flatness near the cutoff frequency and less inductances at the corners of the
amplifier. These are great benefits make the new design to be better than the previous ones
especially in modeling the amplifier in integrated circuit technology. The distributed amplifier
is used in microwave applications.

Automatic voltage regulator AVR is designed for synchronous generator utilizing anti
windup PI controller, to keep the terminal voltage of the generator to the rated value. The
simulation of the synchronous generator is done using Matlab instructions which based on d-q
axes models and the designed AVR as anti wind up PI controller. The results shows when an
inductive load is applied to the generator the terminal voltage drops , the AVR is automatically
increasing the excitation to get rid of this the disturbance as fast as possible

The use of Kohonen self-organizing feature maps in real time applications requires
high computational performance, especially for embedded systems and hence neural network
chips are essential. A digital architecture of Kohonen neural network with learning capability
and on-chip adaptation and storage is proposed with the implementation of Kohonen Self-
Organizing Map (SOM) neural networks on the low-cost Spartan-3 FPGAs. The architecture
of this digital chip based on the idea that some assumptions for the restrictions of the
algorithm can simplify the implementation. Using the Manhattan distance, a special treatment
of the adaptation factor, and neighborhood functions will decrease the necessary chip area so
that a high number of processing elements can be integrated on one chip

This numerical study documents the effect of an adiabatic internal flow partition on
natural convection heat transfer in a two dimensional enclosure filled with saturated porous
media whereas the partition attached vertically on the lower insolated wall. The study
concluded the effect of partition using different lengths (LP=0.3, 0.5 and 0.7), locations
(XP=0.3, 0.5 and 0.7) and different inertia effect (Fs/Pr=10-2, 10-3 and 10-4) on heat transfer
with aspect ratio (A=1.0). A continuity, energy and momentum equations are analyzed and
solved using finite difference with Gauss-siedel iterative method. From results, it’s clear that
the partition caused a deflection on stream lines causing a disturbance in the flow patterns.
This affected the heat transfer rate represented by Nusselt number. Also, for a wide range of
governing parameter, it may be concluded that the partition reduces the heat transfer rate