Journal of Engineering and Sustainable Development (JEASD)

The introduction of more stringent legislation limiting the disposal and use of sewage sludge, combined with an increase in its production and the loss of previously recognized disposal routes, has sparked a search for alternate applications for sewage sludge. The conversion of sludge into adsorbents is one of the promising technologies give a more stable treatment of sludge. In a batch mode adsorption, adsorbent created by recycling sewage sludge was employed as a sustainable and low-cost material to remove pb (II) ions from manufactured polluted aqueous solutions. A laboratory test was done to determine the influence of a variety of operational parameters on Pb (II) adsorption, including the acidic function (pH), absorbent dosage, agitation speed, agitation period, and initial concentration at room temperature. The maximum removal efficiency was 88.2 % at optimum factors pH=4, agitation time =250 rpm, agitation time=180 min, adsorbent dose=1.5 g and initial concentration=50 (mg/l). In this way sewage sludge, which pollutes the environment and is costly to treat, may be disposed of in a useful and economic way to achieve the lowest pb (II) concentration level.

The following work deals with numerical investigation of a storage tank equipped with a mantle annular cavity surrounding it. Heat is transferred via the working fluid flowing in the mantle side to the inner storage tank. Water at constant temperature of 60 oC enters the mantle to heat the tank and exits at a lower temperature. The study is carried out using the commercial software Ansys−Fluent to track the change of water temperature in the tank and mantle side during the simulated period of 60 minutes. Temperature contours of tank water and mantle water are drawn at several time intervals during the simulated period. The effects of changing working fluid mass flow rate were taken into account through three values, namely; 0.0077, 0.015 and 0.02 kg/s. Three values of mantle gap thickness; 10, 15 and 20 mm, and three values of mantle length; 250, 300 and 350 mm were applied in the simulation program and their effects were monitored and displayed. Results show that increasing the value of mass flow rate causes more heat transfer rate to the storage tank. The gap thickness of 10 mm which is the smallest value among the three applied values gave the best heat transfer rate and the mantle length of 300 mm was the optimum among the applied values. The heat transfer rate to the tank was studied in terms of tank mean temperature. The maximum mean tank temperature achieved at the end of the simulated period was 42 oC.

Refrigeration, and air conditioning systems are designed to transport heat from internal spaces or products and discard it into the surrounding. Refutation of heat might happen in a straight line to the air, as in the case of most conventional units of air-source, or to water flowing from a cooling tower. This heat is of a \"low-grade diversity\", it still signifies wasted energy. According to the viewpoint of energy conservation, it would be necessary to regain this heat in a serviceable form. In this research, a practical study aims to collect the heat emitted from the cooling condenser by 35% and exploit it in heating hot water for domestic purposes, in addition to other uses, including reducing the consumption of electrical energy as a result of exploiting and collecting waste heat, from cooling devices using a system consisting of two types of helical heat exchangers and two stages. The first stage consists of a tube-in-tube helical exchanger and the second stage includes a tube-in-shell heat exchanger using R410A refrigerant. The EES engineering equation solving program was used to solve the numerical equations that are used to solve problems related to thermodynamics, due to its high accuracy in solving equations, extracting values and graphs, and calculating the performance coefficient of the COP to obtain better efficiency for the work of the system, as it was found that the higher the temperature, As a result of increasing the flow rate of deionized water, the percentage of performance coefficient of COP has increased to 15%, which should range from (12.5-40) %, which leads to an increase in the efficiency of the system.

This research aims to investigate the impact of fibre reinforcement on the mechanical properties of hybrid polymer matrix composites. The samples made of a hybrid polymer composite were made from the reaction of two polymers, 90% epoxy resin and 10% Resole resin, and were reinforced with two types of reinforcements. The reinforcement used for the current research was carbon and Kevlar fibers. The fibers were in plain weave and were added in volumetric fractions. This research assessed mechanical characteristics like tensile strength, hardness, and impact strength in two cases: one for epoxy/Resole blend only and the other for a hybrid composite material. The addition of fibre reinforcement improves the mechanical properties of the epoxy. Kevlar fiber provides the best mechanical properties for the epoxy/Resole blend when reinforced with two layers of kevlar fibers.

The current work aims to inspect the influence of formation flow on hydrothermal performance and the uniformity of base temperature in the serpentine mini channel heat sink. The study was conducted by changing the flow formation with the straight channel model [A] and the wavy channel model [B] and by changing the place of inlet and outlet by putting the entrance at the heat sink center and using water as the working fluid. To obtain the numerical results, a 3D (ANSYS Fluent program) is used. A comparison between the numerical findings in the current work and experimental results from the literature review is carried out. The comparison shows moral agreement between the numerical and experimental findings. Moreover, the outcomes display that flow configuration has a great influence on the distribution of temperature and pressure drop. Although the model with straight channels enhances the temperature uniformity and pressure drop. Additionally, the overall performance factor (OPF) for all new models under study is better than traditional model. The average OPF for model [A] is (1.43) and for model [B] is (1.26). In addition, model [A] is better as compared with model [B] by 11.89% due to the efficient OPF and the uniformity of temperature in the base.

Recently, LDPC code have become very important research area in wireless communication due to its ability to increase the capacity in a wireless fading environment, with low implementation complexity. In this paper, LDPC are combined with Multi User OFDM Orthogonal Chaotic Vector Shift Keying (MU-OFDM-OCVSK) communication system to improve the BER performance over multi-path Rayleigh fading channels. Two types of LDPC decoder are introduced that are Log-Domain and Min-Sum decoder. The system is simulated using MATLAB program version 2019a for different scenarios which include different number of iterations, different block lengths, different number of users and different number of spreading factor. The results show that a coding gain in a range of (4.5 – 7) dB is achieved between the coded and uncoded MU-OFDM-OCVSK system. The results also show that the Min-Sum decoder outperform the Log-Domain decoder in all scenarios

Nowadays, the transformation between coordinate systems is the major interested problems especially in Iraq. There are many coordinate systems used to produce maps and documentations due to different datums and spheroids. These coordinate systems are preferable to be unified in local countries. Thus, this paper deals with the transformation of coordinate systems of Karbala 1979 Polservice and World Geodetic System (WGS) 1984 to Iraqi Geospatial Reference System (IGRS). Accurate and well distributed control points are selected to cover the study area in Baghdad city, Iraq. Coordinate transformations are implemented using ArcGIS application mainly. Also, MATLAB software is used to convert geographic to map coordinates and vice versa by designing two MATLAB programs. The differences between the coordinate systems have been calculated. The results found that the discrepancies between Karbala 1979 Polservice and IGRS are about 278.6 m, -287.6 m, 0.01 second, and -11.2 second in northing, easting, latitude, and longitude, respectively. The WGS 1984 is superposed to IGRS and the distinction between them is negligible. The map coordinate differences between ArcGIS and MATLAB results are about -16 to 14 mm in northing and about -13 to 12 mm in easting, while the latitude and longitude differences are zero.