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Aims and Scope
Editorial Board

1. Computational investigating the combination of finned heat sink and phase change material as a cooling technology for a solar panel to be applied in arid areas

Ahmad Elamaireh, Jaydeep Goraniya, Madeleine L. Combrinck

Northumbria University, Newcastle-upon-Tyne, NE18ST, United Kingdom.

Abstract: This paper entails a computational investigation that aims to examine the effects of applying Phase Change Materials (PCM) and fins as a cooling technology for the Photovoltaic (PV) panel system in arid areas. In previous case studies, it is noticeable that PCM heat transfer showed to be a weak point, therefore, the focus of this investigation is to enhance the efficiency of the heat transfer between PCM and the ambient atmosphere by applying fins on the container of PCM. Enhancing the heat transfer helps PCM to remain in its transitional phase, which allows PCM to absorb latent heat (LH). The findings of this paper show the effects of combining PCM and fins, evidencing that it decreases the temperature of the PV panel’s surface temperature around 7 K for a heat flux and the ambient temperature of 750 W/m2 and 318.15 K respectively.

2. Feedstock and supply chain-oriented comparative cradle-to-gate life cycle assessment of torrefied pellets, case study: Finland

Raghu KC, Jarno Föhr, Olli-Jussi Korpinen, Tapio Ranta

Lappeenranta-Lahti University of Technology LUT, Laboratory of Bioenergy, Lönnrotinkatu 7, 50100 Mikkeli, Finland.

Abstract: Life cycle assessment (LCA) is used to compare global warming potential of torrefied pellets made of different feedstock materials, namely energy wood of birch and pulpwood of birch, pine and spruce. In addition, five different supply chain alternatives for each feedstock type are also evaluated. It is assumed that all of the biomass originates in the South Savo region of Finland and the pellets are used for co-firing with coal in a large-scale power plant in Helsinki, Finland. The results show that the torrefied pellets made of pulpwood of birch have the lowest global warming potential, whereas energy wood of birch impose the greatest environmental burden. Of the supply chain alternatives considered, biomass chipped with an electrical chipper in the torrefaction plant yard in South Savo has the lowest global warming potential. Consequently, torrefied pellets of birch chipped in an electric chipper in the torrefaction plant yard have the lowest environmental impact of all feedstock material and logistics alternatives. On the other hand, energy wood torrefied on-site in Helsinki results in the greatest environmental impact of all the raw material and logistics alternatives assessed. Furthermore, logistics with roadside mobile chipping generates 5-17% lower greenhouse gas (GHG) emissions than terminal crushing. Similarly, moving the torrefaction plant from South Savo to Helsinki would cause up to 6.5% additional GHG emissions depending on the raw material. Alternatively, chipping at the plant yard in a stationary electric chipper instead of crushing with a diesel-powered crusher would cause up to 18% fewer GHG emissions depending on the raw material.

3. Comparison of the ultra-filtration and cation exchange membrane performance in photo electro catalytic degradation of methylene blue

Seyed Ali Rahmaninezhad, Nasser Mehrdadi, Zaynab Mahzari

Environmental Engineering Department, University of Tehran, Tehran, Iran.

Abstract: Energy gathering from hardly biodegradable and toxic industrial wastewaters, especially textile disposals during their treatment is a promising achievement that could be provided by advanced oxidation methods, like Photo-Electro-Catalysis (PEC). The current density and efficiency of organic removal as dependent parameters can be influenced by the type of anode and cathode separating membrane. In this study, the performance of PEC on Methylene Blue (MB) as an organic material and produced power is evaluated by comparing Ultra-Filtration (UF) and Cation Exchange Membranes (CEM). The results show that in the case of CEM, the removal percent of MB in anolyte is more than that of UF membrane, while the produced power between anode and cathode electrodes are more in UF case. Moreover, the increase in electric conductivity of catholyte has a direct relation to the performance of PEC both in UF and CEM case, while it is more effective in UF case. Also, the investigation of six applied kinetics models reveals the MB concentration of anolyte photodegradation in case of CEM has higher order of magnitude rather than UF case.

4. Effects of cigarette butts addition on thermal conductivity and ceramic properties of brick clay

Marina Jovanović¹, Adnan Mujkanović¹, Erna Tutić², Tatjana Volkov-Husović³

1 University of Zenica, Faculty of Metallurgy and Technology, Travnička cesta 1, 72000 Zenica, Bosnia and Herzegovina.

2 University of Zenica, Polytechnic Faculty, Fakultetska 1, 72000 Zenica, Bosnia and Herzegovina.

3 University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, Serbia.

Abstract: The influence of the addition of cigarette butts, as dangerous waste material, to the properties of the brick clay "Čavka" near Busovača was studied. The cigarette butts were added to the clay in amounts of 5 mass% and 10 mass%. Testing of the samples included testing of consistency, plasticity, Atterberg plastic and liquid limits, drying and firing behavior and refractoriness. Also, apparent density, apparent porosity, water absorption, flexural and compressive strength were investigated on the samples fired at different temperatures. Thermal conductivity was tested on sample fired at 1173 K. Addition of cigarette butts improved insulation characteristics and drying sensitivity, while other properties remain within the required limits for brick industry.

5. Analysis of the dynamic behavior of the cracked stepped shaft used in the rotating equipment

Muhsin. J. Jweeg¹, Salah. N. Alnomani², Salah. K. Mohammad²

1 Al-Farahidi University, College of Engineering Technology, Iraq.

2 University of Kerbala, College of Engineering, Mechanical Engineering Department, Iraq.

Abstract: The main objective of this research is to study the impact of cracking on the static and dynamic behavior for the purpose of faults diagnoses. Experimental and numerical analysis techniques were used for an intact shaft and for a cracked one. The natural frequency, dynamic response, equivalent stresses and total deformation of the static and dynamic behavior of uncracked and cracked rotors were detected. Several cracks with different values of depths and locations were performed for this purpose. The ANSYS package was used in numerical analysis to simulate the behavior of cracked shafts during operation and to correlate the vibration effect with the specific cracks on the shaft. The experimental work was completed by manufacturing a test rig consisting of a rotary part to monitor the dynamic behavior of the testing model. The resulting data was recorded and saved by a computer program (SIGVIEW). The effect of the crack on the response, the natural frequency, stress, and the total deformation was determined by measuring the dynamic frequency response and the vibration for each acceleration that will give a pointer to the control system, and to achieve numerical and experimental analysis during the study of centrifugal pumps and steam turbines. Results show a good agreement between numerical and experimental analyses, it was found that the maximum variance was equal to (10.55%) for the bending frequencies and (10.51%) for the torsional frequency and the dynamic response increases by 26% to 33% and the critical speed decreases by 15% to 20% at crack depth (12mm), This is very important in the detection and diagnosis of early cracks and sclerosis for the purpose of avoiding catastrophic failure.

6. Material characterization and stress analysis of elastomer tyre

Muhsin J. Jweeg¹, Emad Qasem Hussein², Dalya Talib Jazzaa²

1 Al-Farahidi University, College of Technical Engineering, Baghdad, Iraq.

2 Department of Mechanical Engineering, Faculty of Engineering, University of Kerbala, Iraq.

Abstract: The fiber pre-tension method was used to improve the tyre bead ply mechanical properties by applying stresses range between (0-1250 MPa) on each single wire in the specimen. The following results were a comparison between specimens with pre-stressed wires by tension of (1250 MPa) and with non-pre-stressed wires. The results show that the tensile strength and maximum tensile strain of bead specimens increased by (60.87 %) and (23.6%) respectively. The stress strain curves for specimens show a high increase in strength as compared to a little increase in strain. The modulus of elasticity (Young's Modulus) of bead specimens increased by (54.125 %). Also, the results show that the Fatigue life of bead specimens increase by rise Number of cycles by (93.4%). The numerical part is implemented using a (FEM) built on ABAQUS software to examine the influence of passenger tyre modification of bead on dynamic behavior of the tyre. The influences of various pre-stresses levels were applying in model to investigation the rolling and sliding condition. The result showed (von mises, Max. principal stress and Tresca) was increase with increasing pre-stresses while (Min. principal stress and pressure) was decrease with increase pre-stresses.