Journal of University of Babylon

Welding joints of materials that are difficult to weld with traditional methods, particularly polymeric materials, require friction stir welding (FSW). In this research, two types of polymers have been used to study the effect of friction stir welding (FSW) parameters on the properties of dissimilar polymer joints. High density polyethylene (HDPE) and polyvinyl chloride (PVC) plates with dimension of (5x100x200 mm) were welded by using milling machine as friction stir welding machine. The welding tool was used with shoulder diameter of (18 mm) and pin diameter of (6 mm) with height of (4.8 mm). The rotation speed was applied in the range of (340 to 1660 rpm) with welding linear speed of (24 and 40 mm/sec). The result shows that the hardness was increased with increasing rotational speed until (850 rpm) then decreased when the welding speed equal to (24 mm/sec). However, its decreased with increasing welding linear speed when it became (40 mm/sec). In addition, the maximum hardness and tensile strength was found at rotational speed equal to (495 rpm) and welding linear speed equal to (24 mm/sec) which equal to hardness of (72 Shore D) and tensile strength of (39 MPa). Finally, the result displays that there is an opportunity to weld dissimilar polymers.

Design this industrial model aim to reduce the radon radioactive gas concentration which depending on the mixing of many reactive gases like, hydrogen which explosion when mixing with oxygen by ratio of 2: 1, nitrogen, oxygen and carbon dioxide gases with a single hydrocarbon manufactured through a generation of self-unit using the anaerobic digester process. Use electronic detonator to obtain the partial explosion inside the combustion chamber which designed for this purpose, use also dual thermal furnaces for obtaining higher degrees than (650Co) to reach the first ionization level energy which equals to (1037 kJ /mol), reaches this level helps radon gas to transfer from inactive status to interactive case with the found of potassium hydroxide and purified carbon materials. Use also many gauges to measure voltage, heat, and power as well as to show the form of thermal shock which wave produced during the partial explosion processes. Use electronic thermal gauges at each stage of of this model. Effective cooling system used due to high temperatures at each stage as one of occupational safety devices. When doing all thermal processes, roasted the carburetor gas mixture through an ionization chambers with voltage exceeds than (1500 volts), ionization chamber consists of two electrodes made of zinc for the purpose of conducting the decomposition ions to positive and negative. Radon congregates at the anode and transfer to another material called carbonyl as a resinous substance, this material is has no any effect on human health. Results proved that there is a sharp decline in concentration after treatment more than 52% in air with standard deviation equal to (5.6), results also proved low concentration of gas in water more than (40%) after treatment with standard deviation equals to (7). This design has high economic feasibility in comparison with the cost of treatment of when exposure to this gas in the absence of treatment. Thermal shock chamber was used in the three test stages, cooling and heating systems were used through the work, in addition use multi measuring devices. Results showed decrease in the concentration of radon gas by (40%) after conducting a series of different treatment processes. The main objective of this research is to reduce the concentration of this gas through our system to treat areas polluted with this gas.

Generalized Frequency Division Multiplexing (GFDM) is one of the candidate schemes for the 5G and beyond. Its multicarrier modulation scheme and structure are independent blocks, and each block contains sub-carriers and sub-symbols. Sub-carriers are filtered with a prototype pulse shaping that shifts by time and frequency domain. This work uses Genetic Algorithm (GA) to assign the best parameters of the pulse shaping filter, which uses the error as a cost function. The algorithm assigns its parameters based on a minimum error by iteratively processing until reaching the pulse values that give the minor error. This method gave the advantage of reducing the error generated due to orthogonality and thus gave improved performance. This method initially depends on searching for filter values that provide the lowest error value and then adopting these values in building the GFDM transmitter and receiver. This method reduced the BER to 0.0107 at 10 SNR and 0.0033 at 25 SNR compared with the traditional method. Thus, this is a new method for building a GFDM transceiver system.

Asphalt concrete or a dense graded mixture is an acceptable additive used to improve the performance and longevity of asphalt road materials (DGM). The use of various recycled materials as fillers is one of many diverse strategies used to reduce the impact of moisture damage on the pavement, as well as to reduce cost, improve road efficiency, and reduce the harmful impact of solid waste by recycling it. Alkalinity, coarse surface roughness, fine particles preventing air gaps, increasing the bonding between asphalt slurry and aggregate, and improving moisture sensitivity are all characteristics of fillers.
It can be constructed so that it works well as a filler to increase the quality and durability of the pavement. It is essential to understand previous research pappers and investigations. The VOS Viewer was used to visualize the data in early tests. Keyword data was downloaded in Excel format from the Dimension, Web of Science, and Scopus websites. Lists these terms, authors, and researchers by country. With the help of the terms (hot asphalt), (asphalt sensitivity to moisture), (additives) and (wet damage), the researcher was able to conduct a study that was identical to his or her study.

Al2O3 and Fe2O3 has been added as a nanoparticles (200 nm) 2.5 wt.%, to study their effects on microstructure and mechanical properties of pure Al by casting. Nanotechnology is now taking new processes to enhance the strength of metals and plastics. Lately, the remarkable magnetic, electric, optical, and catalytic capabilities of metal oxide nanoparticles like Al2O3 and Fe2O3 have received a lot of attention. Examination of microstructure, hardness, wear, and tensile has been conducted. All the data showed that adding nanoparticles had a significant impact on the properties compared with the properties of pure Al; for example, hardness increased by (20, 53)%, and volume wear loss by (27.7, 69.7)%. Moreover, increasing reach to (82, 254)% in UTS and (52, 107)% in yield point. These outcomes result from significant microstructural improvement (refining of grain size).

This paper studies the generation of an optical mitigation method for compensation of distortions in long distance fiber optic transmission caused by chromatic dispersion and the nonlinear Kerr effect in multi-channel systems. A hybrid new method known as Optical Phase Conjugation (OPC) based highly nonlinear fiber with Raman amplifier is used as part of the process of improving the performance of communication systems with an 800 km standard single mode fiber link Single Polarization Quadrature Amplitude Modulation (SP-QAM) signaling. This work presents two scenarios in which backward Raman amplification is employed in conjunction with OPC to improve the performance of an optical link of 1.728 Tb/s over sixteen channels with a channel spacing of 50 GHz. In this study, through the use of multiple OPC, the performance of dense wavelength division multiplexing (DWDM) transmission systems with 16 ×108 Gbps 8-QAM channels can be significantly improved over that of systems with either a mid-span optical phase conjugation or no optical phase conjugation. The strategy of using multiple OPCs is effective over a variety of transmission links. The nonlinear threshold in the proposed transmission system was enhanced by 4 dB when employing multiple OPCs, compared to the case with no OPC, and by 2 dB when using a mid-span OPC. The simulation results show that compared to the scenario without employing the compensation approach, the Q-factor, Bit Error Rate (BER) performance, and total length of the transmission link are all improved by utilizing this optical method of nonlinearity compensation