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Using magnetic nanoparticles for contaminant removal has received considerable attention for their unique properties. The novelty of this study lies in the integration of electrocoagulation with magnetite nanoparticles for the treatment of oily wastewater, where these processes have been used individually in previous studies. Such combination and enhancement will reduce the requirements for time, power, and cost to reach the allowable limits of oil content. The used commercial magnetite was characterized by XRD, FT-IR, and SEM. Moreover, the experiments were conducted in a batch electrocoagulator with aluminum and iron plates as anode and cathode, respectively. Four parameters were studied, namely pH, current density, time, and magnetite dosage. The results verified that the current density required to obtain 90% oil removal efficiency for the 275-ppm initial oil concentration decreased from 25 to 15 mA/cm2 after the addition of 0.93 mg/L magnetite to the electrocoagulation process and time decreased from 30 to 10 min, which is an indication of the enhancement of nanoparticles in the electrocoagulation process. Furthermore, the minimum oil content reached by the electrocoagulation + magnetite process was 8.9-ppm at the optimum current density of (20 mA/cm2), while electrocoagulation process provided 22.2-ppm final oil content at the same operating conditions. The adsorption kinetics could be well described by pseudo-second-order model. The Langmuir isotherm model showed a better fit with experimental data compared with Freundlich isotherm model. The treated oily wastewater by the electrocoagulation + magnetite process was found to be feasible for reusing in other processes or reinjection in the oil fields.

Magnetic nanoparticles are now being investigated widely in field of water treatment. The aim of this study was to evaluate the feasibility of electrocoagulation process combined with addition of magnetite nanoparticles as a turbidity removal process. Bentonite was used as source of turbidity for the synthetic turbid water. Experiments were conducted in a bench scales electrocoagulation reactor where voltage was applied across a perforated plate of aluminum as anode, and iron mesh as cathode. Commercial grade of magnetite (Fe3O4) with an average nanoparticle size of 50 nm was used. The effect of some factors such as initial pH of the solution (5-9), current density (5-25 mA/cm2), and magnetite dosage (0.4-2.5 gm) on the efficiency of the process were studied. The residual turbidity obtained by using electrocoagulation process alone was (7.47 NTU) from initial turbidity of (200 NU) at constant conditions of pH 6, current density 15 mA/cm2 and electrolysis time 20 min. While under these same conditions the combined electrocoagulation + magnetite process with the added (1.4 gm) of magnetite and under the same operating conditions the residual turbidity was (4.34 NTU), which indicate that the magnetite nanoparticles enhanced the electrocoagulation process.

Due to fast-paced advancements in technology and innovation, new product development (NPD) has received great attention from industries. This development can assist companies to maintain their business's competitive edge. However, NPD task is a risk and complex process which is normally handled by NPD teams. These teams are currently lacking effective procedures to enhance their efforts to develop truly innovative products. Hence, this paper aims to develop a new systematic approach for new product development by integrating TRIZ principles into the Design for six sigma methodology. The proposed method will be effective in triggering creative concepts for innovative products and applied for a wide range of products. Refereed/Peer-reviewed

The global impact of shale oil has revolutionized the world’s energy markets, resulting in significantly lower oil prices, higher global gross domestic product, changing geopolitics and shifted business models for oil and gas companies. Further and developed research initiative is required to fill critical gaps in knowledge at the interface of shale oil development along with environmental protection, so countries can prepare better for its energy future. This paper explores the characterization of Iraqi originated oil shale using various analytical techniques, such as mass spectrometry (MS), infrared spectroscopy (IR), and Gas Chromatography Mass Spectrography (GC/MS). Based upon analytical results, it is found that the majority of chemical structure is in aliphatic hydrocarbon forms. Validerad;2018;Nivå 1;2018-02-05 (rokbeg)

A walking worker assembly line (WWAL), in which each cross-trained worker travels along the line to carry out all required tasks, is an example of lean system, specifically designed to respond quickly and economically to the fluctuating nature of market demands. Because of the complexity of WWAL design problems, classical heuristic approaches are not capable of solving problematic design characteristic of WWAL of very large design space. This paper presents a new genetic approach to address the mixed model walking worker manual assembly line optimisation design problem with multiple objectives. The aim is to select a set of operational variables to perform to the required demand for two product models. The goal is to produce the required models at the lowest cost possible, whilst keeping within an ergonomically balanced operation. Genetic algorithms are developed to tackle this problem. This paper describes the fundamental structure of this approach, as well as the influence of the crossover probability, the mutation probability and the size of the population on the performance of the genetic algorithm. The paper also presents an application of a developed algorithm to the operational design problem of plastic electrical box assembly line. Refereed/Peer-reviewed

Edited version of paper first presented at 11th Global Congress on Manufacturing and Management (GCMM 2012), AUT University, Auckland, New Zealand, 28-30 November 2012. Manual assembly lines with walking workers may be designed in many configurations. Different configurations have profound impact on the performance of the system. This paper analyses and evaluates the ergonomics performance measures for different system configurations. Based on developed mathematical model, different combinations of structural factors are compared to evaluate effects of these factors on the mentioned performance. The work demonstrates that various design factors should be considered jointly when designing or redesigning walking worker assembly line because setting different levels for factors can considerably affect the ergonomics performance of the system. Refereed/Peer-reviewed

The newest assembly system is lean assembly, which is specifically designed to respond quickly and economically to the fluctuating nature of the market demands. Successful designs for these systems must be capable of satisfying the strategic objectives of a management in manufacturing company. An example of such systems is the so-called walking worker assembly line WWAL, in which each cross-trained worker travels along the line to carry out all tasks required to complete a job. Design approaches for this system have not been investigated in depth both of significant role in manual assembly process design; productivity and ergonomics. Therefore these approaches have had a limited success in actual applications. This chapter presents an innovative and integrated framework which offers significant potential improvement for productivity and ergonomics requirements in WWAL design. It establishes a systematic approach clearly demonstrating the implementation of a developed framework based on the simultaneous application of mathematical and meta- heuristic techniques. Refereed/Peer-reviewed

Designing a dynamic system with inherent randomness requires a predictable and dependable mathematical model accurately representing the essential aspects of real systems.So it is necessary to establish a confidence level in the mathematical model of this system by carrying out a verification process for this model to collect evidence. This paper deals with verification of the mathematical model designed for the prediction of performance of manual assembly lines occupied by a flexible workforce referred to as walking worker(s) assembly line (WWAL). To verify the mathematical model, it was applied to an illustrative industrial example.Also experiments carried out on this example were simulated using a software package. Then, the predicted results of the mathematical model were compared with simulation results. Comparison leads to the verification of both the accuracy and the serviceability of the mathematical model developed. Refereed/Peer-reviewed

Manual assembly lines, with workers travelling with the work along the line to perform all required tasks, are an example of assembly systems which have greater flexibility over traditional systems due to an improved response to product demand variability. Implementing assembly systems in this way is difficult, especially when operational design reflects an incomplete understanding of how workers can best perform within the system. Different operational designs for such systems have a profound impact on the performance of the system in terms of productivity and ergonomics. This paper analyses the performance of walking worker assembly line (WWAL) in different operational designs. A mathematical model was developed, which considers the effects of a number of operational design variables. An industrial case study is presented here to demonstrate the effectiveness of the proposed model. The results indicate that WWAL can be designed to improve performance, flexibility and labour costs by approaching productivity and ergonomics collaboratively. The results obtained by the model prediction were compared with computer simulation results. Comparison validated the accuracy of the proposed model. The model provides partial characterisations of the optimal design of WWAL and can be used to develop heuristics for local or global optimisation. Refereed/Peer-reviewed

High worker-hour productivity and improving ergonomics conditions are major concerns of industry, especially in human-centred production systems (e.g. manual assembly systems). From the view of some manufacturing managers, converting fixed worker assembly line to walking worker assembly line (WWAL) involves opportunities and pitfalls for both mentioned aspects. This view point is supported by the complaint, i.e. no modelling research that can help them to develop their own capacity in the design of WWAL considering both productivity and ergonomics. This paper proposes a mathematical model that can be used by designers, manufacturers and dealers for the effective design of WWAL that significantly affects the productivity and ergonomics performance measures. Different combinations of process design parameters are compared with several alternative scenarios of WWAL design using well-planned numerical experiments. Graphical analyses were carried out to examine the relationships between design parameters (factors) and performance measures. The model can support WWAL practices in two ways: firstly, it can improve the understanding of how such systems behave and what factors drive performance. Secondly, it can help to determine what types of policies for successful operation of this system can quickly and economically be selected in light of the different levels of production demand. Refereed/Peer-reviewed

Designing a dynamic system inherent with randomness requires predictable and dependable mathematical models that focused well on variability of the output. In addition, the model should provide an understanding for the impact of that randomness on the model validation as an abstraction for the real system. Lack of this fact causes inaccuracy in the results from the mathematical model, especially when modelling systems with high manual work content such as manual assembly lines with walking worker(s) (WWAL). This paper deals with validation of the mathematical model of WWAL and effect of sources of randomness in the system on worker operating times and in the end on the output of the system. Refereed/Peer-reviewed