Anbar Journal of Engineering Sciences

The aim of this paper is to in investigate the performance characteristics of counter
flow wet cooling towers experimentally by varying air and water temperatures,
fins angle, rate of air flow, rate of water flow as well as the evaporation heat transfer, along the height of the tower.
The analysis of the theoretical results revealed before that the thermal performance of the cooling tower is sensitive to the degree of saturation of inlet air.
Hence, the cooling capacity of the cooling tower increases with decreasing inlet air
temperature whereas the overall water temperature fall is curtailed with increasing
water to air mass ratio. From the experimental study the efficiency of the cooling
tower and cooling tower characteristics are higher in case of low mass flow ratio
due to higher contact area of water to air. Because of better contact area between
airs to water the drop in performance of the cooling tower is less.
The effect of fins angle on the thermal performance of counter flow wet cooling
tower was predicted. The experimental study showed that the cooling range, cooling coefficient, , heat load , change in air relative humidity and cooling tower effectiveness increased with increasing fins angles and optimum fins angle obtained
from this experimental work was 70 degree, at this angle all cooling tower performance has been calculated were better.
While the approach increased with decreasing fins angles, the minimum approach
was obtained for 70 degree fins angles and the maximum approach was obtained
for 30 degree fins angles.

The impact resistances of concrete slabs have a different volume fraction replacement of waste
plastic aggregate has been examined in this study as a fine aggregate as: 0% (reference), 10%,
20% and 30%. These tests include the splitting tensile, density, compressive strength. Also, the
(ultrasonic pulse velocity tests) was carried out. Repeated falling mass was used in order to carry
out the low-velocity impact test in which a 1300 gm steel ball was utilized. From a height of
2400mm, the ball falls freely on concrete panels of (500×500×50 mm) with a network of waste
plastic aggregate. As per the results, a prominent development was seen in the mechanical properties for mixes involving polyethylene aggregate up to 20% as compared to the reference mix. A
significant development was seen in low-velocity impact resistance of all mixes involving waste
plastic fine aggregate as compared to reference mix. As per the results, the greater impact resistance at failure is offered by the mix with (20%) waste plastic aggregate by volume of sand
than others. The reference mix increased by (712.5%)

The main purpose of this search is to study the punching shear behavior of fourteen specimens of
Reactive Powder Concrete (RPC) two-way flat plate slabs, half of these slabs have been exposed
to a high temperature up to 400 C° by using an electric oven. All slabs have dimensions of
(400x400x60) mm, with steel reinforcement mesh of (Ø6mm) diameter. Laboratory tests show
that there is an increase in the value of First Crack Loading (FCL) and Ultimate Load (UL) by (208,
and 216.67) % and a decrease in deflection by (56.85) % due using slab with complete reactive
powder relative to a slap made of normal concrete. The use of the (RPC)mixture in layers in slabs
gave results close to the slab which consists of full (RPC) this gives the benefit of more than the
use of a slab that contains full reactive powder concrete in terms of cost, the increase was in FCL
and UL by (130.8, 169.23, 102.7 and 135.135) % and a decrease in the value of deflection by
(37.17, 47.64) %. The use of a partial reactive powder mixture also showed good results, and by
increasing the dimensions of the RPC area, the results were better. the increase in FCL and UL by
(54, 116, and 185) % and (53, 116.67, and 166.67) % and a decrease in value of deflection by
(36.12, 42.4, and 50.26) % from reference slab.
When slabs are subjected to high temperatures, there may be a decrease in the value of the FCL
and UL and an increase in the value of deflection when compared to models not exposed to high
temperature. But when compared to the reference slab with the same circumstance showed an
increase in the value of the FCL and the rate ranged between (50- 200) % and the UL was the
ratio ranged between (51.35-208.1) % and a decrease in the value of the deflection where the
ratio ranged (21-46) %

The behaviour of multiple cracked cantilever composite beams is studied when subjected to moving periodic force. In this investigation a new model of multiple cracked composite beams under
periodic moving load is solved. Three cracks are considered at different position of the beam for
numerical solution. The results from experimental work compared to numerical solution. The
multiple cracks are identified easily from the deflection graphs at different force speed. Influences
of crack depth at different load speed are investigated.

This investigation provides experimental results and nonlinear analysis by using finite element
model of thick hollow core slab made from recycled lightweight material. Four hollow core slabs
specimens were cast and tested in this investigation with dimensions (1200mm length, 450mm
width and 250mm thickness). The crushed clay brick was used as a coarse aggregate instead of
gravel. The iron powder waste and silica fume were used in order to increase the compressive
strength of concrete. The techniques reduction hollow length and use shear reinforcement were
used to improve shear strength and avoid shear failure. The specimens were tested by applying
two-line load up to failure. The experimental results were showed these techniques were resisted
the shear failure significantly and works to change failure mode from shear to flexural failure.
Finite element computer software program (ANSYS) was used to analysis hollow core slabs specimens and compare the experimental results with the theoretical results. Good agreement have
been obtained between experimental and numerical results

RSM and DOEs approach were used to optimize parameters for hypoeutectic A356 Alloy. Statistical analysis of variance (ANOVA) was adopted to identify the effects of process parameters on the
performance characteristics in the inclined plate casting process of semisolid A356 alloy which
are developed using the Response surface methodology (RSM) to explain the influences of two
processing parameters (tilting angle and cooling length) on the performance characteristics of
the Mean Particle Size (MPS) of α-Al solid phase and to obtain optimal level of the process parameters. The residuals for the particle size were found to be of significant effect on the response and
the predicted regression model has extracted all available information from the experimental
data. By applying regression analysis, a mathematical predictive model of the particle size was
developed as a function of the inclined plate casting process parameters. In this study, the DOEs
results indicated that the optimum setting was approx. (44) degree tilt angle and (42) cm cooling
length with particle size (30.5) μm

The porous Titanium is characterized by high permeability which can assure the ingrowth of
bone tissues, and consequently results in a good bonding between the metallic implant and the
bone. In this work, Silicon element was added to the Commercially Pure Titanium at different
weight percent of (2, 4, 6, 8 and 10) to investigate its effect on the porosity percentage, mechanical properties of the resulted samples. XRD analysis stated that at (Si) content lower than (2
wt%) the alloy is single phase (α- Ti alloy), as the Silicon content increased, in addition to (α-
phase), (Ti5Si3) intermetallic compound developed in the alloy. Porosity measurement results
showed that the porosity percentage increases with the increase in Silicon content. Wear results
stated that the wear rate increases with the increase in silicon content due to the increase in
porosity percentage while the hardness results stated that there is no significant effect for Ti5Si3
intermetallic compound on improving the hardness of the samples. This is attributed to its low
percent and the major effect of porosity on hardness which declined the effect of Ti5Si3 by reducing the hardness of the alloy compared with the master sample. The obtained results of the (yield
strength, ultimate compressive strength and Young’s modulus) were within the values that match
bone’s properties. This means these materials are suitable for biomedical application.

The published studies about the water quality of Euphrates River in Iraq till now have been reviewed critically. The revision of the published researches depend upon several bases including
the period of samples collection, the number of sampling stations, water samples collection
method, the analytical techniques employed to measure and analyze the results. This critical
study concluded that the need to follow a specific protocol in selection sampling sites, how the
samples are collected, how samples are analyzed, and pay attention to quality assurance and
quality control during sample collection, preservation and analytical procedures.

This work, studied the effect of pulse repetition rate on the micro hardness for each of the surface
and cross section by using pulsed ND-YAG laser with laser parameters (Energy = 4.12J).The
distance off between the output nozzle and the minimum spot size on the surface of sample was
(12mm),and pulse duration was (1.8ms).The results showed that the micro hardness increased
after laser treatment ,but the micro hardness decreased with increase pulse repetition rate for
both the surface and cross section of the pulses. The micro hardness increased as moving away
from the molten zone towards the end of the pulses at the heat affected zone due to increase in
cooling rate.

The reliability of water supply system is a critical factor in the development and the ongoing
capability to succeed in life and people's health. Determining of its, with high certainty, for performance of water supply system is developed to ensure the sustainability of system. Reliability
(Re) plays a great role in evaluation of system sustainability. The probability approaches have
been used to evaluate the reliability problems of systems. The probability approach is failed to
address the problems of reliability evaluation that comes by subjectivity, human inputs and lack
of history data. This research proposed two models; I) traditional model: fuzzy reliability measure suggested by Duckstein and Shresthaand then developed by El-Baroudy; and II) developed
model: fuzzy reliability-vulnerability model. The two models implemented and evaluation of
water supply system by using two hypothetical systems (G and H). System (G) consists of a single
pump and System (H) consists of a two parallel pumps. Triangular and trapezoidal membership
functions (MFs) are used to investigate of the reliability measure to the form of the membership
function. The results agree with expectations that the reliability of parallel component system
{ReH (0.53)} is higher than the reliability of single component system {ReG (0.47)}. Moreover, the
result by using fuzzy set reduces the effect of subjectively in process of decision-making (DM).
The fuzzy reliability vulnerability is able to handle different fuzzy representations and different
operation environment of system

The Artificial Neural Network (ANN) and numerical methods are used widely for modeling and
predict the performance of manufacturing technologies. In this paper, the influence of milling
parameters (spindle speed (rpm), feed rate (mm/min) and tool diameter (mm)) on material removal rate were studied based on Taguchi design of experiments method using (L16) orthogonal
array with 3 factor and 4 levels and Neural Network technique with two hidden layers and neurons. The experimental data were tested with analysis of variance and artificial neural network
model has been proposed to predict the responses. Analysis of variance result shows that tool
diameters were the most significant factors that effect on material removal rate. The predicted
results show a good agreement between experimental and predicted values with mean squared
error equal to (0.000001), (0.00003025), (0.002601) and (0.006889) respectively, which produce flexibility to the manufacturing industries to select the best setting based on applications.