Al-Nahrain Journal for Engineering Sciences

In this research, polymer polymethyl methacrylate PMMA
composite with nano ceramic Zr and HAp material were used to
manufacture one part of the implant system (femoral ball head of hip
implant). Three set of hybrid materials were fabricated and tested for this
study; the first mixtures which contains 100% (PMMA), the second
mixtures which contains (90% (PMMA) + 8% (Zr) + 2% (HAp)), and
the third mixtures which contains (80% (PMMA) + 18% (Zr) + 2%
(HAp)) were investigated. The mechanical properties for these mixtures
increased with the increasing of nano ceramic concentration (Zr and
HAp) composite material in the polymer compared to pure polymer
PMMA sample. However, an increase in the concentration of Zr from
8% to 18% content cause a considerable decrease of the hardness where
a drop of homogeneity in Zr- matrix PMMA contact occurred, V
Hardness value are (68 ,80 and 70) Kg.mm for three mixture respectively.
The wear test was in agreement with results of the hardness test. The
weight loss of the above samples of the wear test were (0.041, 0.035 and
0.037) respectively. According to mechanical properties, the best sample
contains (90% (PMMA) + 8% (Zr) + 2% (HAp)). The Scanning electron
microscopy resolute showed the particles forming semi-continuous
network along grain boundaries polymer for second sample mixtures
containing (90% (PMMA) + 8% (Zr) + 2% (HAp)), provides a low
atomic packing and high energy. This will make the grain boundaries
more reactive and strengthen mechanical performance. The Optical
microscopy, Scanning electron microscopy and Xray spectroscopy
analysis for In vitro test using SBF shows the growth of HAp layer with
an increase in concentration of Ca and P elements formed on the surface
of the second sample. This display of good results is a proof of the
biocompatibility of the polymer sample.

In this work it had been focused on the possibility of replacement of steel spring in suspension system by fiber reinforced polymer composite that is responsible for light weight of spring which leads to reduces the weight of vehicle and improve fuel efficiency. This type of spring used in motor cycles, light weight vehicle. The design will be simulated by ANSYS workbench. Then, E-Glass fiber has been used to fabricate helical compression spring of 40% fiber volume fraction of glass. with polyester resin. The deflection of glass reinforced composite spring is more than steel spring but within permissible limit. weight of composite spring is reduced by 57% than of steel.

Heat recovery (HR) is often mentioned as a device that operates between two heat sources in different temperatures. In this device, the heat is transferred from one side to another in order to have a heat balance. Therefore, the device is working on preheating/precooling supplying air to the space by waste heat. The main aims of this work are to design and manufacture of a plate heat exchanger (PHE) with a high efficiency and low cost, calculate the cost of the PHE unit and compare it with the other HEs model from different companies. The PHE was manufactured at the University of Technology from aluminum plates in a simple and inexpensive way. The performance of the HE was evaluated in different external conditions and different air flow rates. The maximum effectiveness value of the HE is 50.76% at a condition of hot air side (DBT= 41⁰C, RH=21%, W=10.2 g/kg, and air flow rate = 0.476 ????³/s) and a condition of cold air side (DBT= 22.2⁰C, RH=92.02 %, W=15.6 g/kg, and air flow rate = 0.476 ????³/s).

As internet network developed rapidly in the past ten years, and its operating environment is constantly changing along with the development of computer and communication technology, the congestion problem has become more and more serious. Since TCP is the primary protocol for transport layers on the internet, the data transmitted via the transport protocol utilizes Vegas Transmission Control Protocol (TCP) as the congestion control algorithm, where it uses increasing in delay round trip time (RTT) as a signal of network congestion. However, this congestion control algorithm will attempt to fill network buffer, which causes an increase in (RTT) determined by Vegas, thereby reducing the congestion window, and making the transmission slower, Therefore Vegas has not been widely adopted on the Internet. In this paper, an improved algorithm called TCP Vegas-A is proposed consist of two parts: the first part is sending the congestion window used by the algorithm for congestion avoidance along with the TTL (Time To Live) mechanism that limits the lifetime of a packet in the network. While the second part of the algorithm is the priority-based packet sending strategy, and jitter is used as a congestion signal indication. The combination of the two is expected to improve the efficiency of congestion detection. A mathematical model is established, and the analysis of the model shows that the algorithm has better effects on controlling congestion and improving the network throughput, decreasing packet loss rate and increasing network utilization, the simulation is done using NS-2 network simulation platform environment and the results support the theoretical analysis

The heavy metals are considered dangerous pollutants which harm health and environment. The adsorption process is the cost effective process to get-rid of heavy metal efficiently. In this study, the adsorption bed of Nickel is simulated by using COMSOL Multiphysics to find the effect of different operating parameters namely; flow rate, temperature and pollutant concentration on adsorption bed efficiency. The modeling of non-isothermal adsorption bed based on experimental isotherms kinetic of previous work is developed too. The results showed that the optimal conditions to generate maximum removal efficiency of heavy metal were at 50◦C inlet temperature, 0.1 M inlet concentration, and 80 ml/min flow rate to achieve removal values higher than 50 % of long operation period time.

A proposed modern technique for determination the blood group typing by monitoring the agglutination of red blood cells using acousto-optical technique and digital camera. The method based on analysis the digital image of the agglutination process by MATLAB software.
We present an overview of two acousto-optic sensing approaches; the first demonstrates the cuvette approach while the second is the microscope slide approach. The cuvette approach digital image analyzing depends on the green channel distribution of the original image and count the brighten pixels, while the microscope slide approach passes through series of algorithms started with grayscale filter and end with edge detection it counts the different color pixels.
The experimental result shown that it is possible to enhance the determination of blood group typing by using acousto-optical technique in both cases of using isohemagglutinating sera as well as the crossmatch test in a short time and high efficiency compared with the traditional methods.

This has led to huge damages to the infrastructure of some main cities. The traditional construction methods seem not to be able to fulfill the rapid reconstruction works needed, while prefabricated building systems seem to be promising. This paper aims at evaluating the possibilities of using prefabrication systems for schools building as a pilot study for wider adoption. An extensive literature review was carried out to identify the features of construction prefabrication and its requirements. Then a thorough investigation of the possibilities of adopting this approach in Iraq and the major expected obstacles was carried out. A questionnaire survey has been conducted with (96) stakeholders who have experience in prefabricated building projects. The results showed that the highest rating of benefits went to time and productivity, while the highest rating of obstacles went to lack of government support. Therefore the top proposed action included the adoption of a clear governmental strategy for change. Finally, the respondents agreed that school building is the most suitable type of projects to start with.

The effects of the repeated solution heat treatment on hardness, tensile strength and microstructure of aluminum were investigated. For this purpose, an alloy of AA6061-T6 was undergo to cyclic solution heat treatment process which is composed of repeated period (10 min) held at 520 °C for 1, 4, 8 and 12 cycles. The hardness was tested for five aging times (as quenching, one week, three weeks, one month and five months) to all cycles (1, 4, 8 and 12) firstly and it is found that the hardness of five months as aging time for all cycles has the best results (90Hv) as compared with others (as quenching, one week, three weeks, and one month), so it was adopted for all cycles to implement the tensile test and the microstructure. Hardness results were improved to Vickers hardness of (90Hv) with increasing of cycles up to 8 cycles then decreasing after that to (45Hv). Tensile results were showed an increment (34%) also for the same group of 8 cycles compared with (17%) and (9%) for 4 and 12 cycles, respectively. Microstructure is revealed that whenever cycles are increased, the precipitate phase in alloy is increased also, thus, it is improved the hardness and tensile strength.

Authors affiliations:
1*) Automated Manufacturing Engineering Department, University of Baghdad, Baghdad, Iraq.
ghadakmohammad8@gmail.com,

2) Mechanical Engineering Department, University of Baghdad, Baghdad, Iraq.
fathyalshamma@gmail.com

3) Automated Manufacturing Engineering Department, University of Baghdad, Baghdad, Iraq.
enaslaser77@kecbu.uobaghdad.edu.iq

Paper History:
Received: 21st June 2020
Revised: 4th Sep. 2020
Accepted: 21st Nov. 2020 Abstract
In this paper the ability of fabricating laminate composites by manual layup was discussed. Heating method was used to manufacture the composites; heat was applied to approximately 12 hours with specific heat temperature. There were four types of laminate composites fabricated and studied in this research, containing Aluminum alloy 6061 as the common element in all types, two types of fibers; woven Carbon fiber with two different orientations: ±45°, ±60°, random fiberglass and with two types of resin; epoxy resin and polyester resin. Different types of composites were made to determine the effect of CNC milling machine to the measured surface roughness and for specified parameters. The weight fraction ratio of the fibers is 37%, polymer is 34% and 29% for Aluminum. The parameters selected are spindle speed, feed rate and depth of cut. The L9 Taguchi orthogonal arrays, signal to noise (S/N) ratio and analysis of variance (ANOVA) are selected to determine the effect of these parameters; it was analyzed by MINITAB 17 program. The results showed that the parameter were significant more to the epoxy resin specimens than polyester resin specimens. The optimal milling parameters for good surface finish for Aluminum – Carbon fiber composite are at 3000RPM, 1200mm/min, 1.2mm, and for Aluminum – Fiberglass composite are 5000RPM, 1800 mm/min, 2.0mm.

Pick and place system is one of the significant employments of modern robots utilized in industrial environments. The objective of this research is to make a comparison of time sequences by combining multiple axes of sequences. A pick-place system implemented with pneumatic linear double-acting cylinders to applicator in automated systems processes for manufacturing. The challenge of 3-axes movement control was achieved using the PLC (Programmable Logic Controller) controller such that the merging between two or three axes was achieved according to the selected sequence of the program. The outcomes show the contrasted sequences and the reference in a constant velocity. The main variable parameter is the number of steps for each sequence. The combination of two axes has developed the sequence and reduced in number of sequences for a path. At last, one of the important factors in moving products industry is the smooth product’s movement, because any high speed might cause a vibration in the system and lead to a decreased positioning accuracy.

Deep learning modeling could provide to detected Corona Virus 2019 (COVID-19) which is a critical task these days to make a treatment decision according to the diagnostic results. On the other hand, advances in the areas of artificial intelligence, machine learning, deep learning, and medical imaging techniques allow demonstrating impressive performance, especially in problems of detection, classification, and segmentation. These innovations enabled physicians to see the human body with high accuracy, which led to an increase in the accuracy of diagnosis and non-surgical examination of patients. There are many imaging models used to detect COVID-19, but we use computerized tomography (CT) because is commonly used. Moreover, we use for detection a deep learning model based on convolutional neural network (CNN) for COVID-19 detection. The dataset has been used is 544 slice of CT scan which is not sufficient for high accuracy, but we can say that it is acceptable because of the few datasets available in these days. The proposed model achieves validation and test accuracy 84.4% and 90.09%, respectively. The proposed model has been compared with other models to prove superiority of our model over the other models.