Iraqi journal of mechanical and material engineering

The presence of oil and grease in the industrial effluents has a very bad impact
on both the treatment units and the disposal media. One of the important oil/ water
separation techniques is the Induced Air Flotation.
The principal aim of this paper is to determine the proper air flow rate for oil/ water
separation, in a laboratory scale IAF batch system, for two types of industrial waste
waters; Sweets and Dairy Industries. The impact of Alum as a coagulation agent, on the
separation efficiency via flotation process, is also studied.
Results have shown that (3-5 l/min.) air flow rates are the optimal for having separation
efficiencies between (77%- 80%) for effluent of Sweets industry, and (66%- 70%) for
effluent of Dairy industry.
The addition of (0.5 g/l) Alum has proved significant influence on oil/ water separation
efficiency, which could reach the values of (96%- 99%), using the air flow rates
mentioned above, for Dairy and Sweets industrial effluents respectively.

The construction sector is usually considered the most important sector among
other sectors .The estimation cost of items plays great role in project execution .This
paper concludes that implementing standard formula in calculating the productivity of
excavating equipment reflects directly on the cost analysis of the project, where the
management has been proved the dominant in this era.

The quantities of heat transfered through horizontal concrete roof which used in
Iraqi residence building was redused by inclination that roofs small angle because ,
inclined roofs is unpopular in Iraqi building, and that small angle not appear that the
surface is inclined). This study was undertaken in Baghdad city (lat.33.3N) with changed the inclined
Building ceiling from 0 to 5, and the orientations of that ceiling is changed eight times
with assuming many ways to afford that inclination, the concrete ceiling was inclined ,
clay layer is level to afford that angle or used inclined steel structure (which covered
with many insulating materials).
At last the researcher found that , the maximum saving in electrical energy for
purpose cooling at inclined concrete ceiling by 5 at North orientation is 11% and then
North-East & North-West. And the South, South-East, South-West orientation was
neglectful, because it's opposite effects, and also the researcher found that level clay
saving 55% from ordinary electrical energy, but it's very heavy on ceiling and increases
it's dead loads, while, the inclined steel structure with fired clay covered saved 48.2%
and become 38.4% when used reeds stalks sheaye 25mm thickness beside the asbestoscenent
by light class fiber..

The aim of this research to use extracted natural material from waste product of
Okra as blowing material by simple method for production sponge rubber with good
damping properties. The sample of rubber was prepared with adding different percent
from extracted material of waste product of Okra (0-25)% to study the effect of this
material on properties of natural rubber. When we added blowing material that
extracted from plant of Okra ,we get productions of cells inside the sample due to
release gases and get sponge rubber. This mean is extracted material of waste product
of Okra is suitable to use as blowing material to get sponge rubber and this work exists
with a good replacement for synthetics blowing materials avoiding their toxicity and
their highly cost.

The walk is the oldest uses in the means of transport it is very important for
pedestrians in order to reached their destination or any other operations although the
walk is the main activities for the pedestrian which have the best results on human
health as well as the vehicles can not reach to the distention in some times unless by
walk. the main problem in this study is the random crossing of pedestrian with no
control on there movement also the geometric design of Al Hilla city highway network stop avoid the pedestrian problem therefore this research attempted to analysis the
exists condition of pedestrian crossing then found some solutions in order to reduce the
weaving condition between pedestrian characteristics and traffic operating. Pedestrian
traffic volume data had collected in all study area during filed survey within peak hour
volume period . the research choose four sectors to described the pedestrian
characteristics they are ( 60 street , 40 street , bab Al Hoseen area and Babylon health
office intersection ) which they are residential, commercial, and education area
according to al hill master plan , also the research efforts to study the sidewalk
conditions and its suitability in the study area , the research use home interview method
to learn the suitability of over pass crossing . the study recommended to construct over
pass crossing for pedestrians with Carrey belt stairs and make the legislation and
education for use them .

Two dimensional unsteady seepage through a zoned earth dam was investigated
by the finite element based on Galerkin method. The coefficients of permeability are
assumed to vary in terms of geometry, external load influences and the effect of head
distribution in the flow domain and the resulted nonlinear seepage problem is solved.
The effects of drawdown rates and various material parameters on pressure heads
variation were discussed. The results show that the zoned dam permeability has
important influence on pressure heads variation as the height of the dam increases. It is
believed that a variable permeability analysis such as the one presented in this work
should be taken into account.

Highway and its intersection in every country are the mirror of the civilization
and the scale of the progress through out the highway quality , number and the traffic
facilities in the intersection . An intersection define as an area shared by two or more
roads , whose main function is to provide for the change of route directions .
Intersection vary in complexity from a simple intersection which has only two roads
crossing at a right angle to each other , to amore complex at which three or more roads
cross within the same area . This research effort to evaluate and improve Nader and Al
thowra intersections . Traffic volume data have been collected for each approach and
every movements ( Through , Left and Right ) within peak hour volume in the (pm ,
am) period for each intersection . Traffic volume classification was don due to vehicles
types which they are moving throw the intersections . data was collected by using
photographic technique method then translated it in tables and figures .Data was
analysis in order to estimate level of service ( LOS) for each intersection by using
Highway Capacity System ( HCS 2000) . Data analysis results indicate that LOS type for each intersection by using Highway Capacity System ( HCS 2000) . Data analysis
results indicate that LOS type F for the both intersections . the research attempt to
improve the geometric design for the both intersections and the analysis led to rise LOS
to type C . the study recommended to prevent stopped vehicles and buses in the
intersections area with prepare garage outside them as well as protected right
movement by using slip road before stopped area especially in Nader intersection also
operating them with traffic light according to traffic volume and type of movement in
each directions to reduce delay time and traffic accident probability.

The hot corrosion is largest danger for the alloys used in high temperature. This
study is concluded experiment for two types of steel using in steam boilers of electrical
station in south of Baghdad, these samples represent different places in burnt rooms of
boiler included steel (1045, 213T11), the ordinary oxidation processes conducted for
specimens of steel in the temperature (550-650, 750, 850, 950°C) for different times
and then different temperature are used with constant times (3hrs.).
Coating process for specimens by impurities material in the following
percentage (67%wt.V2O5:33wt.Na2SO4) are performed. This impurity material forms
when steel undergoes hot gases which contain sulphur sodium and vanadium which
react with each other to produce this system, and after this the oxidation processes for
samples were done .We calculate the change in weight with respect to the area at
temperatures (550, 650, 750, 850°C) for different times and then used the inhibitor
material (MgO) to decrease the effect of impurities on the steel samples and the
oxidation processes doing and calculated the change in weight.
The inhibition material are added with rations (1Ash:1Inhibitor, 1Ash:2Inhibitor
and 1Ash:3Inhibitor). The study shows that the steel oxidation processes at this temperatures(550,650,750,850C) led to form thick, porous, week adhesion oxides, and
the mechanism of oxidation change from weight gain to weight loss and the weight loss
is small when the inhibitor used especially at the ratio (3 Inhibitor:1Ash) that gives best
results.

The internal combustion engines are generally a major source of air pollution.
However the spark ignition engines are recognized by their carbon monoxide and
unburned hydrocarbon emission. One of the methods used to reduce the emission of
these pollutants is the blending of hydrogen with the gasoline fuel, either on a mass
basis or on energy replacement basis. The present research study is devoted to concern
with developing a numerical model to predict the effect of hydrogen blending (based on
energy replacement) on the emitted concentrate of carbon and nitrogen oxides and the
temporal and local variation of cylinder temperature.
It is found that hydrogen blending improves combustion process by increasing
the flame propagation speed and hence increasing maximum cylinder temperature. The
timing of maximum cylinder temperature is also advanced due to hydrogen blending.
It is also found that the hydrogen blending reduces CO and CO2 concentrations
and increases NOx concentrations. It is found that when the hydrogen blending ratio
exceeds 20% the engine performance is deteriorated.

By using a simple maximum load failure criterion, material toughness can be
determined from load-deflection curves measured during testing of notched flexural
specimens. The J-integral (Jc) and the stress intensity factor (Kc) results as a measure
of toughness have been determined using four point loading edge notched beams.
Generally, there is a good agreement between these two results which describe the
fracture characteristics of steel fibre reinforced concrete (SFRC). The fibre content
varies between 0% and 1.5% by volume with perpendicular, parallel and random
orientations to load application were adopted in this paper. Increasing the fibre content
results in increased kIc results and also results of JIc. The enhancement of cracking
strength, ultimate strength and fracture toughness for the previous fibre content and
orientation are reported.

The primary schools buildings are considered from the most important features
of the basic items in any country, which aid in evaluation and development, in which
we put our effort to take care and give it the needed consideration. Therefore it
demands continues research which is the best type of help in the evaluation as well as
development as to serve the evaluation of teaching series in our country.
This research aims to evaluate the building of the primary schools in Al-Hilla
city according to the construction, function and diagnoses of the construction problems
that result from execution or the design or miss using by giving the incomplete
solutions to get rid of these obstacles and its treatments.
In order to achieve this aim, data collection have been made from information that
have been obtained from some literatures about evaluation of the primary schools
buildings, in addition to other information that has been obtained from field survey for
the buildings of the schools in Babylon governorate, alongside collective and personal interviews with specialist from teachers as well as administration, besides collecting
data about technical and engineering side by giving important engineering ideas, and
others which are really in touch with the concern matter.
Results of data analysis have showing many negative points exist in the schools
buildings, and it is assured by the results of field survey hence the diagnoses is
completed by the construction problems and more clarity. One of them the absence of
the periodic maintenance for schools, as well as the absence of the special staffs and
sub-staffs that under takes these responsibilities.

Improving road traffic safety has high effect to reduce the cost of traffic accident
and save the user of highway. Since 1985 the average stopped delay has been used as
the measure of service in signalized intersections analyses , on the other hand it is
difficult to evaluate the traffic safety in terms of change in number of traffic accident,
because the traffic accidents accord has no reliable accident recorded ,while it not only
reflect the number of accidents well, but also their nature ; traffic conflict technique is
an efficient tool for analyses traffic safety.
This study is aimed to developed traffic safety at 4 four- leg signalized intersections
in Baghdad City. Regression analyses is performed to relate hourly traffic conflict and
average stopped delay .Specific categories of countermeasures such as signalization
and geometric countermeasures are adopted. HCS 2000 software are adopt to determine
the average stopped delay before and after countermeasure implemented.
The results show that the negative exponential model related hourly traffic conflict
to average stopped delay and show a better explanation rather than linear model ,as
well as it is found that exponential model explains increasing variation (81.6 ) of total
hourly traffic conflict in relation with average stopped delay . The highest reduction in
number of traffic conflict after signalization countermeasures is 74.63% more than the
highest reduction after geometric countermeasures when it reduce by 58.07% . This
study recommends to use traffic conflict technique as a tool to improve traffic safety by
any proposed countermeasures.

By The Conventional Solid State reaction is used to prepared the (ZnFe2O4
,NiFe2O4 ) From the Oxide of (Fe ,Zn ,Ni ) while had emphasized the Crystallize
Synthesis accurately and Sort by these Synthesis by using the Technique (X.R.D)
it is mixed to Formed the final Synthesis (Ni1-xZnxFe2O4 ) with (x=0.4 ,0.6) as a ring
are sintered at (1350◦c ) for several tenses ,the Practical result of these Synthesis
show the [Ni0.4 Zn0.6 Fe2O4] was the baste sample to use as core at low Frequency
(50 Hz) N0.1