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  • Single-Element and MIMO Circularly Polarized Microstrip Antennas with Negligible Back Radiation for 5G Mid-Band Handsets

    Alnahwi, F.M.; Al-Yasir, Yasir I.A.; See, C.H.; Abd-Alhameed, Raed A. (2022-04)
    In this paper, single-element and MIMO microstrip antenna with two pairs of unequal slits is proposed as a circularly polarized antenna with negligible back radiation for 5G mid-band handsets. The unequal pairs of slits are engraved on the antenna patch to guarantee the presence of the circular polarization (CP). The proximity-coupled feeding technique is used to excite the proposed microstrip antenna in order to provide larger antenna -10 dB bandwidth which approaches 10.8% (3.48-3.87 GHz). A novel analysis technique is proposed in this paper that demonstrates the 3D axial ratio pattern in order to generate CP in the broadside direction without affecting the structure of the ground plane which ensures weak back radiation. The 3 dB axial ratio bandwidth (ARBW) is found to be equal to 4.1% extended along the range (3.58-3.73 GHz). To make the design more compatible with the 5G mid-band handsets, the 2 × 2 MIMO structure of the proposed antenna with reduced mutual coupling (less than -20 dB) is also presented in this work. The simulation and measured results are in good agreement, and both verify the CP characteristics and the weak back radiation of the proposed antenna.
  • Demonstrating the Potential of Using Bio-Based Sustainable Polyester Blends for Bone Tissue Engineering Applications

    Ramos-Rodriguez, D.H.; Pashneh-Tala, S.; Bains, A.K.; Moorehead, R.D.; Kassos, Nikolaos; Kelly, Adrian L.; Paterson, T.E.; Orozco-Diaz, C.A.; Gill, A.A.; Ortega Asencio, I. (2022-04)
    Healthcare applications are known to have a considerable environmental impact and the use of bio-based polymers has emerged as a powerful approach to reduce the carbon footprint in the sector. This research aims to explore the suitability of using a new sustainable polyester blend (Floreon™) as a scaffold directed to aid in musculoskeletal applications. Musculoskeletal problems arise from a wide range of diseases and injuries related to bones and joints. Specifically, bone injuries may result from trauma, cancer, or long-term infections and they are currently considered a major global problem in both developed and developing countries. In this work we have manufactured a series of 3D-printed constructs from a novel biopolymer blend using fused deposition modelling (FDM), and we have modified these materials using a bioceramic (wollastonite, 15% w/w). We have evaluated their performance in vitro using human dermal fibroblasts and rat mesenchymal stromal cells. The new sustainable blend is biocompatible, showing no differences in cell metabolic activity when compared to PLA controls for periods 1-18 days. FloreonTM blend has proven to be a promising material to be used in bone tissue regeneration as it shows an impact strength in the same range of that shown by native bone (just under 10 kJ/m2) and supports an improvement in osteogenic activity when modified with wollastonite.
  • Reduction of scour around circular piers using collars

    Pandey, M.; Pu, Jaan H.; Pourshahbaz, H.; Khan, M.A. (2022-03)
    River dynamics and sediment transport play an important role in river bed morphology. Building a bridge pier along the river alters the cross-section of the river and causes the change in flow processes. These changes are mainly responsible for pier scour. In this paper, the usage of collars to reduce scour around circular piers has been investigated. The collars with different diameters and depth positions have been studied using previous data and additional data collected in the present study to assess their effectiveness in reducing scour. Using a wide range of measured data, an empirical equation to compute the maximum scour depth around the circular piers in the presence of collars has been proposed. The proposed equation has been validated and proven to be applicable to a wide range of pier layouts. It has been found that the maximum efficiency can be achieved by fixing the collar at bed level and adopting a collar diameter 1.5–2.5 times of pier diameter.
  • Improving bond of fiber-reinforced polymer bars with concrete through incorporating nanomaterials  

    Wang, X.; Ding, S.; Qiu, L.; Ashour, Ashraf A.; Wang, Y.; Han, B.; Ou, J. (Elsevier, 2022-06)
    The bond between FRP bars and concrete, the foremost performance for implementation of such reinforcements to corrosion-free concrete structures, is still unsatisfied due to the weak nature of duplex film in the interface. The existing approaches show low efficiency in improving the microstructures and bond between FRP bars and concrete. To address these issues, this paper provided a new approach for improving the bond between FRP bars and concrete by incorporating nanomaterials, as well as explored the modifying mechanisms and established the bond-slip models. For these purposes, the pull-out test, scanning electron microscope observation, as well as energy dispersive spectrometry analysis were performed. The experimental results demonstrated that the presence of nanomaterials increased the ultimate bond strengths between glass/carbon FRP bars and concrete by up to 16.2% and 37.8%, while the corresponding slips decreased by 28.7% and 35.4%, respectively. Such modification effects can be attributed to the optimized intrinsic composition and the reduced pore content of hydration products in the interface, especially in the duplex film, through the nanomaterial enrichment and nano-core effects. The bond-slip relationship between FRP bars and concrete with nanomaterials can be accurately predicted by the mBPE model.
  • 3D simulation of the Hierarchical Multi-Mode Molecular Stress Function constitutive model in an abrupt contraction flow

    Olley, Peter; Gough, Timothy D.; Spares, R.; Coates, Philip D. (Elsevier, 2022-06)
    A recent development of the Molecular Stress Function constitutive model, the Hierarchical Multi-Mode Molecular Stress Function (HMMSF) model has been shown to fit a large range of rheometrical data with accuracy, for a large range of polymer melts. We develop a 3D simulation of the HMMSF model and compare it to experimental data for the flow of Lupolen 1840H LDPE through an abrupt 3D contraction flow. We believe this to be the first finite element implementation of the HMMSF model. It is shown that the model gives a striking agreement with experimental vortex opening angles, with very good agreement to full-field birefringence measurements, over a wide range of flow rates. A method to give fully-developed inlet boundary conditions is implemented (in place of using parabolic inlet boundary conditions), which gives a significantly improved match to birefringence measurements in the inlet area, and in low stress areas downstream from the inlet. Alternative constitutive model parameters are assessed following the principle that extensional rheometer data actually provides a ‘lower bound’ for peak extensional viscosity. It is shown that the model robustly maintains an accurate fit to vortex opening angle and full-field birefringence data, provided that both adjustable parameters are kept such that both shear and extensional data are well fitted.
  • Flexible design and operation of multi-stage reverse osmosis desalination process for producing different grades of water with maintenance and cleaning opportunity

    Al-Obaidi, Mudhar A.A.R.; Rasn, K.H.; Aladhwani, S.H.; Kadhom, M.; Mujtaba, Iqbal M. (2022)
    The use of Reverse Osmosis (RO) process in seawater desalination to provide high-quality drinking water is progressively increased compared to thermal technologies. In this paper, multistage spiral wound RO desalination process is considered. Each stage consists of several pressure vessels (PVs) organised in parallel with membrane modules in each PV being organised in series. This allows disconnecting a set of PVs and membrane modules depending on the requirement of cleaning and maintenance. While this flexibility offers the opportunity of generating several RO configurations, we presented only four such configurations of the RO system and analysed them via simulation and optimisation. Production of different grades of water catering different needs of a city is also considered for each of these configurations. The optimisation has resulted in the optimal operating conditions, which maximises the water productivity and minimises the specific energy consumption of the proposed configurations for a given water grade in terms of salinity. For instance, the results indicate that the proposed RO networks can produce drinking water of 500 ppm salinity with a minimum specific energy consumption of 3.755 kWh/m3. The strategy offers the production of different grades of water without plant shutdown while maintaining the membrane modules throughout the year.
  • Effect of chloride corrosion on eccentric compression response of concrete columns reinforced with steel-FRP composite bars

    Ge, W.-J.; Zhu, J.-W.; Ashour, Ashraf F.; Yang, Z.-P.; Cai, X.-N.; Yao, S.; Yan, W.-H.; Cao, D.-F.; Lu, W.-G. (ASCE, 2022)
    This paper presents test results of eccentrically loaded concrete columns reinforced with steel-fibre-reinforced polymer (FRP) composite bars (SFCBs) subjected to chloride corrosion. The first stage of the experimental work explored the tensile and compressive tests of various reinforcements (SFCBs with different cross section, steel and FRP bars) used in the large reinforced concrete (RC) columns after chloride corrosion with or without sustained stresses. The results showed that the tensile and compressive stress-strain relationships of SFCBs are characterised by stable secondary (post-yield) stiffness. The second stage of the testing investigated the structural performance of RC columns with various amounts and types of reinforcements, slenderness ratio, applied load eccentricity and chloride corrosion rate. The results showed that the effect of reinforcements on eccentric compression behaviour is significant. The deformation and crack width of SFCB RC columns, respectively, decreased by 12.2%~52.6% and 8.5%~71.0%, while the load capacity improved by 0.9%~18.8%, when compared with the corresponding FRP RC columns having the same eccentricity and reinforcement ratio. The use of SFCBs as the reinforcement of RC columns, especially with high reinforcement ratio or SFCBs having high area ratio of inner steel to SFCB, is beneficial to reduce the deflection and crack width as well as improve the bearing capacity utilization coefficients under serviceability limit state.
  • Properties of geopolymers sourced from construction and demolition waste: A review

    Alhawat, Musab M.; Ashour, Ashraf F.; Yildirim, Gurkan; Sahmaran, M. (2022-06-01)
    Geopolymers have been recognised as a viable replacement to ordinary Portland cement (OPC), providing a cleaner solution since it can significantly reduce greenhouse gas emissions as well as accomplishing effective waste recycling. Construction and demolition waste (CDW) has been recently identified as raw materials for geopolymers due to its availability and high contents of silica and alumina. This paper aimed at reviewing the current state-of-the-art on the geopolymer paste, mortar, and concrete production and their properties, with special attention paid to geopolymers incorporating CDWs. The review covers brief assessment of using CDWs in concrete, the mix design of geopolymer mixtures in addition to identification of the main factors influencing the performance of geopolymer containing CDW. The most recent data related to the mechanical and durability properties of CDW-based geopolymers are presented, while the cost and environmental impacts of using recycled materials in producing geopolymer concretes are also discussed. Geopolymer concretes have a vast range of possible applications, however, there are still several barriers facing commercialisation of geopolymers in construction industry. The review indicated that it is possible to produce geopolymer concretes from CDW-based materials with properties comparable to OPC-based ones; however, the selection of proper material composition should be carefully considered, especially under normal curing conditions.
  • Simulating the Misting of Lubricant in the Piston Assembly of an Automotive Gasoline Engine: The Effect of Viscosity Modifiers and Other Key Lubricant Components

    Dyson, C.J.; Priest, Martin; Lee, P.M. (Springer, 2022)
    The presence of lubricant droplets in the gas that flows through the piston assembly and crankcase of an internal combustion engine (generically termed oil misting) has important implications for performance, particularly lubricant supply to the upper piston assembly, oil consumption and lubricant degradation. A significant source of these droplets is thought to be oil shearing and blow-through by blow-by gas flows in the piston assembly. An experimental rig was developed to simulate the high velocity gas and lubricant film interactions at a top piston ring gap where the flow conditions are most severe. Flows of lubricant droplets were produced and characterised in terms of the proportion of the oil flow that formed droplets in the gas flow and the size distribution of the droplets produced. Considering various aspects of a commercial automotive crankcase formulation, the effect of lubricant viscosity was found to be particularly important. Of the lubricant additives evaluated, viscosity modifiers were found to have the greatest effect on the tendency to form droplets: Detailed study on a range of viscosity modifiers identified that the influence of their molecular architectures on viscoelasticity was the key mechanism.
  • Detection and Diagnosis of Stator and Rotor Electrical Faults for Three-Phase Induction Motor via Wavelet Energy Approach

    Hussein, A.M.; Obed, A.A.; Zubo, R.H.A.; Al-Yasir, Yasir I.A.; Saleh, A.L.; Fadhel, H.; Sheikh-Akbari, A.; Mokryani, Geev; Abd-Alhameed, Raed A. (2022)
    This paper presents a fault detection method in three-phase induction motors using Wavelet Packet Transform (WPT). The proposed algorithm takes a frame of samples from the three-phase supply current of an induction motor. The three phase current samples are then combined to generate a single current signal by computing the Root Mean Square (RMS) value of the three phase current samples at each time stamp. The resulting current samples are then divided into windows of 64 samples. Each resulting window of samples is then processed separately. The proposed algorithm uses two methods to create window samples, which are called non-overlapping window samples and moving/overlapping window samples. Non-overlapping window samples are created by simply dividing the current samples into windows of 64 sam-ples, while the moving window samples are generated by taking the first 64 current samples, and then the consequent moving window samples are generated by moving the window across the current samples by one sample each time. The new window of samples consists of the last 63 samples of the previous window and one new sample. The overlapping method reduces the fault detection time to a single sample accuracy. However, it is computationally more expensive than the non-overlapping method and requires more computer memory. The resulting window sam-ples are separately processed as follows: The proposed algorithm performs two level WPT on each resulting window samples, dividing its coefficients into its four wavelet subbands. Infor-mation in wavelet high frequency subbands is then used for fault detection and activating the trip signal to disconnect the motor from the power supply. The proposed algorithm was first implemented in the MATLAB platform, and the Entropy power Energy (EE) of the high frequen-cy WPT subbands’ coefficients was used to determine the condition of the motor. If the induction motor is faulty, the algorithm proceeds to identify the type of the fault. An empirical setup of the proposed system was then implemented, and the proposed algorithm condition was tested under real, where different faults were practically induced to the induction motor. Experimental results confirmed the effectiveness of the proposed technique. To generalize the proposed meth-od, the experiment was repeated on different types of induction motors with different working ages and with different power ratings. Experimental results show that the capability of the pro-posed method is independent of the types of motors used and their ages.
  • Fuzzy Bayesian estimation and consequence modeling of the domino effects of methanol storage tanks

    Pouyakian, M.; Laal, F.; Jafari, M.J.; Nourai, F.; Kabir, Sohag (2022)
    In this study, a Fuzzy Bayesian network (FBN) approach was proposed to analyze the domino effects of pool fire in storage tanks. Failure probabilities were calculated using triangular fuzzy numbers, the combined Center of area (CoA)/Sum-Product method, and the BN approach. Consequence modeling, probit equations, and Leaky-Noisy OR (L-NOR) gates were used to analyze the domino effects, and modify conditional probability tables (CPTs). Methanol storage tanks were selected to confirm the practical feasibility of the suggested method. Then the domino probability using bow-tie analysis (BTA), and FBN in the first and second levels was compared, and the Ratio of Variation (RoV) was used for sensitivity analysis. The probability of the domino effect in the first and second levels (FBN) was 0.0071472631 and 0.0090630640, respectively. The results confirm that this method is a suitable tool for analyzing the domino effects and using FBN and L-NOR gate is a good way for assessing the reliability of tanks.
  • Optimisation of hybrid MED-TVC and double reverse osmosis processes for producing different grades of water in a smart city

    Al-hotmani, Omer M.A.; Al-Obaidi, Mudhar A.A.R.; John, Yakubu M.; Patel, Rajnikant; Mujtaba, Iqbal M. (2022-07-15)
    The integration of two or more processes in a hybrid system is one of the most desirable options to provide flexibility, interoperability and data sharing between the connected processes. Various examples of hybrid systems have been developed with coherent seawater desalination systems such as the combination of thermal and membrane technologies. This paper focuses on the simulation and optimisation of an integrated (hybrid) system of multi effect distillation and double Reverse Osmosis (RO) processes to produce different grades of water needed in a smart city from seawater resources. The optimisation-based model investigates five scenarios to obtain the highest productivity of drinking water, irrigation water, water for livestock and power plant water, whilst constraining the product water salinity to be within the required standards and with lowest specific energy consumption. For this purpose, multi objective optimisation problem was formulated using the gPROMS (general Process Modelling System) software. The results confirm the superiority of the developed hybrid system to sustain different grades of water in a smart city.
  • Tensile, rheological and morphological characterizations of multi-walled carbon nanotube/polypropylene composites prepared by microinjection and compression molding

    Ezat, G.S.; Kelly, Adrian L.; Youseffi, Mansour; Coates, Philip D. (2022-03)
    Polypropylene (PP) reinforced with 2 and 4 wt% of multi-walled carbon nanotubes (MWNT) were melt-blended in twin screw extruder and then molded by compression or micromolding process. The impact of injection speed on the surface morphology, rheological and tensile characteristics was investigated by using a scanning electron microscope, parallel plate rheometry, and tensiometry. Results showed that the tensile properties of micro-molded specimens were remarkably higher than those of the compression molded sheets. Compared to compression molded sheets, micromolded specimens demonstrated up to 40 and 244% higher tensile stiffness and yield strength, respectively, most likely due to the alignment of polymer chain segments in the flow direction induced during the micromolding process. It was observed that the fast filling speed caused a drop in the tensile properties of the nanocomposites and polymer. Rheological examination revealed that the presence of a rheological percolation network in the nanocomposites produced by micromolding and the fast injection speed was beneficial for establishing the percolated network. Morphological examination revealed that the size of nanotube agglomerations that appeared in micromolded specimens was up to five times smaller than in compression molded sheets and the agglomeration size decreased with the increase of the injection speed.
  • The effect of PEO homopolymers on the behaviours and structural evolution of Pluronic F127 Smart Hydrogels for Controlled Drug Delivery Systems

    Shriky, Banah; Mahmoudi, N.; Kelly, Adrian L.; Isreb, Mohammad; Gough, Timothy D. (2022)
    Understanding the structure-property relationships of drug delivery system (DDS) components is critical for their development and the prediction of bodily performance. This study investigates the effects of introducing polyethylene oxide (PEO) homopolymers, over a wide range of molecular weights, into Pluronic injectable smart hydrogel formulations. These smart DDSs promise to enhance patient compliance, reduce adverse effects and dosing frequency. Pharmaceutically, Pluronic systems are attractive due to their unique sol-gel phase transition in the body, biocompatibility, safety and ease of injectability as solutions before transforming into gel matrices at body temperature. This paper presents a systematic and comprehensive evaluation of gelation and the interplay of microscopic and macroscopic properties under both equilibrium and non-equilibrium conditions in controlled environments, as measured by rheology in conjunction with time-resolved Small Angle Neutron Scattering (SANS). The non-equilibrium conditions investigated in this work offer a better understanding of the two polymeric systems’ complex interactions affecting the matrix thermo-rheological behaviour and structure and therefore the future release of an active pharmaceutical ingredient from the injectable DDS.
  • DDI: A Novel Technology And Innovation Model for Dependable, Collaborative and Autonomous Systems

    Armengaud, E.; Schneider, D.; Reich, J.; Sorokos, I.; Papadopoulos, Y.; Zeller, M.; Regan, G.; Macher, G.; Veledar, O.; Thalmann, S.; et al. (2021-02)
    Digital transformation fundamentally changes established practices in public and private sector. Hence, it represents an opportunity to improve the value creation processes (e.g., “industry 4.0”) and to rethink how to address customers’ needs such as “data-driven business models” and “Mobility-as-a-Service”. Dependable, collaborative and autono-mous systems are playing a central role in this transformation process. Furthermore, the emergence of data-driven approaches combined with autonomous systems will lead to new business models and market dynamics. Innovative approaches to re-organise the value creation ecosystem, to enable distributed engineering of dependable systems and to answer urgent questions such as liability will be required. Consequently, digital transformation requires a comprehensive multi-stakeholder approach which properly balances technology, ecosystem and business innovation. Targets of this paper are (a) to introduce digital transformation and the role of / opportunities provided by autonomous systems, (b) to introduce Digital Depednability Identities (DDI) - a technology for dependability engineering of collaborative, autonomous CPS, and (c) to propose an appropriate agile approach for innovation management based on business model innovation and co-entrepreneurship.
  • Internet of Things and Safety Assurance of Cooperative Cyber-Physical Systems: Opportunities and Challenges

    Kabir, Sohag (IEEE, 2021-06)
    The rise of artificial intelligence in parallel with the fusion of the physical and digital worlds is sustained by the development and progressive adoption of cyber-physical systems (CPSs) and the Internet of Things (IoT). Cooperative and autonomous CPSs have been shown to have significant economic and societal potential in numerous domains, where human lives and the environment are at stake. To unlock the full potential of such systems, it is necessary to improve stakeholders' confidence in such systems, by providing safety assurances. Due to the open and adaptive nature of such systems, special attention was invested in the runtime assurance, based on the real-time monitoring of the system behaviour. IoT-enabled multi-agent systems have been widely used for different types of monitoring applications. In this paper, we discuss the opportunities for applying IoT-based solutions for the cooperative CPSs safety assurance through an illustrative example. Future research directions have been drawn based on the identification of the current challenges.
  • The relations of job stress dimensions to safety climate and accidents occurrence among the workers

    Khoshakhlagh, A.H.; Yazdanirad, S.; Hatamnejad, Y.; Khatooni, E.; Kabir, Sohag; Tajpoor, A. (2021-09)
    Based on a literature review, likely, there is a relationship between job stress and safety climate, and in this way, the accident occurrence is affected. Therefore, the present study was aimed to investigate the relations of job stress dimensions to safety climate and accidents occurrence among the workers using regression models. This cross-sectional study was carried out on 1530 male employees in 2019. People were randomly selected from various departments. The participants filled out the questionnaires, including demographical information and accident history questionnaire, the NIOSH generic job stress questionnaire, and the Nordic safety climate questionnaire. In addition, information on occupational experience and accident history was obtained from the health unit of the petrochemical company. In the end, data were analyzed using statistical tests of bivariate correlation, multivariate correlation, and logistic regression. Based on the bivariate analysis, the variables of job satisfaction (0.998), problem at work (0.900), depression (-0.836), and physical environment (-0.796) among the job stress dimensions had the highest correlation coefficients with the total score of the safety climate, respectively. The results of the logistic regression analysis with the adjustment of the effect of the safety climate indicated that the relationships between the dimensions of the job satisfaction (Wald = 6.50, OR = 4.96, and p-value<0.05) and social supports (Wald = 5.88, OR = 3.20, and p-value<0.05) with the accident occurrence were significant. To increase the positive safety climate and decrease the accident occurrence, industries must try to reduce job stress in the workplaces through controlling the important factors, such as low job satisfaction and poor social supports.
  • A Bayesian network based study on determining the relationship between job stress and safety climate factors in occurrence of accidents.

    Khoshakhlagh, A.H.; Yazdanirad, S.; Kashani, M.M.; Khatooni, E.; Hatamnegad, Y.; Kabir, Sohag (2021-12-07)
    Job stress and safety climate have been recognized as two crucial factors that can increase the risk of occupational accidents. This study was performed to determine the relationship between job stress and safety climate factors in the occurrence of accidents using the Bayesian network model. This cross-sectional study was performed on 1530 male workers of Asaluyeh petrochemical company in Iran. The participants were asked to complete the questionnaires, including demographical information and accident history questionnaire, NIOSH generic job stress questionnaire, and Nordic safety climate questionnaire. Also, work experience and the accident history data were inquired from the petrochemical health unit. Finally, the relationships between the variables were investigated using the Bayesian network model. A high job stress condition could decrease the high safety climate from 53 to 37% and increase the accident occurrence from 72 to 94%. Moreover, a low safety climate condition could increase the accident occurrence from 72 to 93%. Also, the concurrent high job stress and low safety climate could raise the accident occurrence from 72 to 93%. Among the associations between the job stress factor and safety climate dimensions, the job stress and worker's safety priority and risk non-acceptance (0.19) had the highest mean influence value. The adverse effect of high job stress conditions on accident occurrence is twofold. It can directly increase the accident occurrence probability and in another way, it can indirectly increase the accident occurrence probability by causing the safety climate to go to a lower level.
  • Design of a new synthetic nanocatalyst resulting high fuel quality based on multiple supports: experimental investigation and modeling

    Jarullah, A.T.; Ahmed, M.A.; Al-Tabbakh, B.A.; Mujtaba, Iqbal M. (2022)
    In order to meet the environmental legislations related to sulfur content, it is important to find an alternative techniques for deep removal of sulfur components from fuels. So, in this study, a novel nano-catalyst based on iron oxide (Fe2O3) as active component prepared over composite support (γ-Alumina + HY-zeolite) is developed here for efficient removal of sulfur compounds from fuel via oxidation process. The precipitation method is employed first to prepare the composite support and then the impregnation method is utilized to generate a novel synthetic homemade (Fe2O3/ composite support) nanocatalysts that has not been developed in the literature (iron oxide over composite support). The characterizations of the prepared catalysts display that the surface area of the catalyst increases with increasing the amount of Y-zeolite in composite support. The effectiveness of the catalysts is tested by utilizing oxidative desulfurization (ODS) operation under several operating conditions. The results of the experimental work show that the activity of oxidative desulfurization enhances with increasing Y-zeolite, temperature, and batch time under moderate operating conditions. The oxidative desulfurization efficiency followed the order: CAT-1 < CAT-2 < CAT-3. The CAT-3 performed the high removal of sulfur compounds (90.73%) at 100 min and 423 K. The best values of the kinetic parameters of the ODS process are then determined based on experimental data and model based techniques within gPROMS package. Finally, the reactor model is used to determine the optimal operating conditions while maximizing the removal of sulfur compounds leading to cleaner fuel. Where, 99.3% of the sulfur removal has achieved at batch time of 190.6 min, temperature of 543.56 K and initial sulfur content at 0.8668 wt% in the presence of CAT-3 based on the optimal kinetic parameters (order of reaction (n) of 1.9865719, activation energy (EA) at 29.942 KJ/mol and pre-exponential factor (ko) with 622.926 wt-0.9865719. min-1).
  • Diffusion brazing of IN738 to SiC ceramic with Ag-Cu-Ti powder: Effect of bonding time on metallurgical and mechanical properties

    Paidar, M.; Bokov, D.; Nasution, M.K.M.; Mehrez, S.; Ojo, O.O.; Omar Cooke, Kavian (2021-12)
    Diffusion brazing of SiC ceramic to IN738 using an Ag-Cu-Ti powder-mixture as an interlayer was carried out for the first time. The impact of the bonding time (30 and 45 min) on metallurgical features and shear strength of the joints was assessed. The results revealed that raising the bonding time resulted in expanding of the brazing layer from 46.98 µm to 55.31 µm. Besides, increasing the bonding time also enhanced the shear strength of the SiC/Ag-Cu-Ti/IN738 joints.

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