Volume 14, Issue 2, Winter and Spring 2006, Page 1-108
NON LINEAR BUCKLING OF COLUMNS
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 1-11
DOI:
10.33899/rengj.2006.46542
Abstract:
The geometric non-linear total potential energy equation is developed and
extended to study the behavior of buckling and deflection beyond the bifurcation
point and showing columns resistance beyond the Euler load.
Three types of boundary conditions are studied (pin ended, fixed ended and
cantilever). The equation of non-linear total potential energy is solved by exact
method (closed form solution) and compared with other approximated methods
(Rayleigh- Ritz, Koiter’s theory and non-linear finite difference method). The
agreement is found quite enough and satisfactory for most situations of practical
cases.
Key words:
Bifurcation, Buckling, Columns, Finite difference method, Koiter’s theory,
nonlinear buckling and Rayleigh- Ritz method
Effect of Urea on the Engineering Properties of Gyseous Soil
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 1-12
DOI:
10.33899/rengj.2006.46591
Summary
This study investigates the effect of urea product on the engineering properties of
gypseous soil obtained from Baiji area. The investigated soil can be described as
silty soil with low plasticity and high gypsum contents (32% gypsum). The
maximum dry density of the compacted soil increased with the addition of urea up
to 8% urea then decreased.
The direct shear test results showed that the effective angle of the internal
friction (
Trip Attraction Development Statistical Model in Dohuk City Residential Area
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 12-23
DOI:
10.33899/rengj.2006.46545
ABSTRACT
In this study, trip attraction phenomenon has been studied for 20
residential out of 28 traffic zones located within Dohuk city urban area composed
of more than 300,000 in residents. Home-interview travel data provided for the
city are used in addition to special data collected to perform the trip attraction
analysis .Attraction trips are classified into seven types and selected as dependent
variables while other variables like number of dwelling units, employment,....etc.,
are selected as independent variables in the SPSS package to obtain the most
statistically well accepted predicted attraction trip models. Some models like
HBW trips is constant eliminated with good (R2) value. HBSH and HBOH trips
are showing weak correlation with their independent variables like amount of
CBD area and number of retail sales located within CBD area.
Key Word: Trip Attraction
Effect of Depth and Location of Circumferential Cracks on Natural Frequencies of Rotating Shaft
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 13-32
DOI:
10.33899/rengj.2006.46592
Abstract
In this paper, An-Non destructive test procedure was used to study the effect
of depth and Location of circumferential cracks on the vibration characteristics
of the rotating shafts. The first procedure was to measure the natural
frequencies of rotating shaft before renewing circumferential cracks with
different dimensions and depths from the bearing of the rotating shaft using
(vibration analyzer B & K type 2515) apparatus to analyze the vibrational
characteristics during the rotation and comparing it with mathematical analysis
using the method of mounting the rotating shaft. Secondly, a crack of certain
depth and dimension away from the rotating shaft bearing was made. The
measurements of the natural free vibration due to the presence of the crack
were carried out. The study took into consideration the diameter and the length
of the rotating shaft, beside the measurement of the natural free vibration of the
shaft. The practical results showed a decrease in the natural frequencies of
rotating shaft when the crack prested. This decrease was more when the crack
located in areas near the bearing than was located away from the bearing.
Key Word : Shaft, Crack, Circumferential, Frequency, Depth.
Public Transport Study in Dohuk City
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 24-35
DOI:
10.33899/rengj.2006.46552
Abstract
In this study, the public transport in Dohuk City is investigated.
Questionnaire forms were prepared and used to collect socio-economic data from
transit riders, their origins and destinations, trip purpose, and their mode of
transport. Low standard of living residents in this city are captive to use public
transport, with out scheduling of transit, especially males of (18-25) years old.
The people who are using transit their home are far a way from the road for a
distance more than (200)m. Out of the data analyzed some conclusions and
recommendations are presented in order to be considered by experts and
specialists in this city to take them under option in the future to develop the transit
routes and modes.
Key Word: Public Transport Dohuk
Coefficient of Discharge For the Normal and Oblique Weirs with Semi-Circular Crest
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 33-47
DOI:
10.33899/rengj.2006.46595
ABSTRACT
The coefficient of discharge of normal and oblique weirs with semicircular
crest under free over flow conditions was studied experimentally. Forty-five weir
models were constructed and tested.These models classified in to five groups
based on the variation of oblique angle with the canal wall (
Evaluation of Pyrolisis Polypropylene Modified Asphalt Paving Materials
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 36-50
DOI:
10.33899/rengj.2006.46555
Abstract
The main objective of this research study is to investigate the potential use
of pyrolisis polypropylene as modifiers in hot mix asphalt paving mixtures. Seven
different blends including conventional mix were subjected to binder testing such
as rheological tests, as well as to some other tests related to the homogeneity of
the system.
Optimum asphalt content was obtained by Marshall method and used in all
the modified mixes. The engineering properties, including Marshall stability and
indirect tensile strength were determined. Research results indicate that modified
binders showed higher softening point, keeping the vales of ductility at minimum
range of specification of (100cm), and caused a reduction in percent loss of
weight due to heat and air (i.e. increase durability of original asphalt). The results
indicated that the inclusion of pyrolisis polypropylene with asphaltic concrete
mixtures gave a quite satisfactory result in terms of stability and other Marshall
properties, and increase in indirect tensile strength).
Keywords: polypropylene, polymers, asphalt modifiers, Asphalt binders
Some Problems Of The Main Canal In North Jazira Irrigation Project &The Curves Which Are Used In It
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 48-57
DOI:
10.33899/rengj.2006.46618
Abstract
A good alignment of irrigation canal means efficient transport of irrigation water,
least cost of construction and maintenance. In this study we determined some
imported sections of the main canal in north Jazira irrigation project where
sediment & collapse which happened in the banks and the bed of the main canal.
We suggest some methods to stopped or treated them.
Keyword (Alignment Of Canal _ Curve _ North Jazira Irrigation Project)
FREE VIBRATIONS OF SIMPLY SUPPORTED BEAMS USING FOURIER SERIES
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 51-67
DOI:
10.33899/rengj.2006.46558
Abstract
Fourier series will be utilized for the solution of simply supported beams
with different loadings in order to arrive at a free vibration. The equation of the
free vibration is 0
4
4
2
2
2
Patient Privacy in Environmental Context of General Hospitals , Assessment Local Reality
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 58-75
DOI:
10.33899/rengj.2006.46619
Abstract:
The Environmental Context of General Hospital is one of The Composite and
Complex Physical Environments , Which Integrate and Combine Multifunction
and Diverse forms of Human Behavior , Patient Privacy as Concept , Determined
by Surrounding Social / Physical Therapeutic Environment .
This Article Represent The Effects Both of Social Environment Which
Interface Patient and Physical Characteristics of Therapeutic Environments , by
Testing Three Types of Wards in AL-SALAM General Hospital in Mosul , The
Results Indicates The Manipulation of Physical Environment to Get Accepted
Level of Patient Privacy Dose not Works Without Consider Social Interaction
Between Patients Together , Medical Staff and Visitors Where Those Have
Affects in Patient Assessment of Privacy Level.
Key words: privacy, general Hospital
Handwritten Arabic Alphanumeric Character Recognition using BP and SOFM NeuralNetworks
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 68-80
DOI:
10.33899/rengj.2006.46582
Abstract
This paper presents results obtained by applying two neural networks
models Backpropagation (BP), and Self-Organized Feature Map (SOFM) to a new
application of handwritten Arabic alphanumeric character (HAAC) recognition. A
novel method for features extraction, based on a shadow projection is used. Both
networks are trained using Arabic character samples written by different people
(learning set). They are required, after the learning is over, to recognize characters
out of the learning set. Evaluation of the recognition (classification) capability of
the two models for 28 alphanumeric characters is achieved. Depending on the
experimental results, a comparison of both algorithms is done.
The Proportional Relationships System In Islamic Architecture
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 76-86
DOI:
10.33899/rengj.2006.46620
Abstract
The study defines the research problem as a reconsideration or
reformulation of the researches to study of the formation basics of the
proportional relationships in Islamic architecture. The aim of the study has
been determined through the discovery of the terms and concepts in the
proportional relationships system.
The conclusion that have been achieved showed the originality for
the proportional relationships system in the Islamic architecture, which
based on the aesthetic taste that related to the symbolic aesthetic systems and
the acquired knowledge that related to the geometrical mathematics systems
for Muslims, and that how the compositions of the Islamic architecture of the
difference in it's architectural models, with the it's functional types and it's
architectural styles, through one main united though for the formation based
on proportional relationships system
Hydraulic Characteristics of Flow Over Compound Crested Weir
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 81-87
DOI:
10.33899/rengj.2006.46586
Abstract
The hydraulic characteristics of a compound crested inclined weir which
consists of both quarter round and sharp crest weir configuration under free
conditions were studied experimentally in order to investigates the discharge
coefficient Cd and the performance of weirs for discharge . The experimental tests
were carried out on a model of weir manufactured of compound crest shape fixed
perpendicular and inclined with an angles 35°,45° and 60° across the direction of
flow in the experimental channel. Number of flow discharge were dependent.
Results showed that the model with an angle of weir inclination of 35°
with the center line of the channel had a better performance than the other models
(i.e
Optimal Drainage Design Under Iraqi Conditions Using DRAINMOD
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 88-99
DOI:
10.33899/rengj.2006.46589
DRAINMOD is a field and watershed scale water management simulation
model that has been used to design subsurface drainage systems and characterize
drainage and water table control practices in poorly drained soils.
DRAINMOD is also used as a research tool to investigate the performance of
drainage and sub irrigation systems and their effects on water use, crop response,
land treatment of wastewater, and pollutants transport from agricultural fields.
The model is based on a water balance in the profile to quantify hydrologic
components such as infiltration, subsurface drainage, surface runoff, deep and
lateral seepage and evapotranspiration.
The objective of this research is to examine the capability of
DRAINMOD to obtain an optimal drainage systems design for Iraqi conditions
using the information of Dujailah project. This is done by obtaining the minimum
drain depth and maximum spacing that meet the criteria for water table control.
The results obtained from DRAINMOD for the drainage systems design show a
good agreement with those previously obtained for Dujailah project. Therefore
DRAINMOD is a suitable simulation model which can be used to simulate the
performance of drainage and water table control systems in Iraq.
Keywords :DRAINMOD, optimal drainage design, drainage in Iraq
EFFECT OF ARTIFICIAL AGING TIME AND TEMPERATURE ON TENSILE STRENGTH OF DUPLEX STAINLESS STEELS SAF 2205 AND SAF 2304 USING (ABI) TECHNIQUE.
Al-Rafidain Engineering Journal (AREJ),
2006, Volume 14, Issue 2, Pages 100-108
DOI:
10.33899/rengj.2006.46588
Abstract
Two types of duplex stainless steels SAF 2205 and SAF 2305 have been
selected in this study to investigate the effect of aging time and temperature on the
tensile strength using (ABI) technique. Metallographic studies were conducted on
heat treated duplex stainless steels to examine the phase relation ship with tensile
strength.
The results showed that with increasing the aging temperature from 400cº
to 800cº the tensile strength of duplex stainless steels increased and reached its
maximum value at 600cº for 72 hrs. At 1000cº the tensile strength decreased with
increasing the aging time. For both types of duplex stainless steels these results
attributed to metallurgical aspects like carbide precipitation, sigma phase, change
in grain size, etc.