Mussawar Ahmad

Isolation of bacterial strains able to metabolize lignin from screening of environmental samples

To develop a method to detect bacteria from environmental samples that are able to metabolize lignin.

Analysis of the compression characteristics of a PEM stack, development of an equivalent spring model and recommendations for compression process improvements

Optimising the compression process during assembly improves the performance of fuel cells. Sufficient and uniform compression across the x, y and z axes ensures uniform current distribution contributing to stack longevity, minimisation of mechanical stresses and optimisation of the well-recognised compromise between mass transport and ohmic losses. In addition, the sealing media experience the necessary forces required to prevent the leakage of reactant gases and thus increase the efficiency of the system. This research paper evaluates the compression characteristics of a test version of a fuel cell compression rig, designed by Horizon Fuel Cell UK, to inform future assembly line design. A MATLAB code was used to assess the compression homogeneity presented on Fuji Prescale Low pressure films. A spring equivalent model is developed to approximate required compressive force for optimal performance. Optimisation of this model is expected to facilitate the development of a compression process which lends itself to the mass production of fuel cells. Recommendations for improving the current process include the use of electronically controlled cyclic compression and an increase in the number of compression pistons. The key finding of this study is a lack of compression symmetry which is associated with the alignment of the jig or component manufacturing and assembly tolerances.

Ensuring the consistency between assembly process planning and machine control software

Within the context of automated assembly systems, one of the challenges is ensuring that machine program logic is consistent with process planning requirements. A critical inconsistency can arise due to a lack of i) formal engineering tools and methods that link the Process and Resource domains, ii) a standard way to describe the assembly process that maintains a consistent level of granularity, and iii) transparency of the machine program logic from the perspective of the Process domain. This research demonstrates how these problems can be addressed through the use of a Product, Process, Resource (PPR) ontology. The ontology model includes a Skill model that integrates the PPR domains. Due to this, the Process can be described at many levels of granularity and, provided it is linked to the Skill model, the logical sequence relative to the machine can be validated. The approach is tested on a hydrogen fuel cell assembly system where the process is described in two different ways. Nevertheless, the query is still able to ascertain the sequence consistency and execute a check for capability. The impact of this research is to enable more effective communication between domain models and an extensible Skill model that, with implementation into industrial engineering tools, will reduce costs, time-to-market, and increase responsiveness as errors in the engineering change process are mitigated.

A knowledge-based approach for the selection of assembly equipment based on fuel cell component characteristics

Unpredictable and dynamic markets are driven by an ever more informed customer base and rapid technological evolution. In order stay competitive, organisations producing physical products need to be agile. To realise a product, an organisation must go through several phases including product design, process planning and manufacturing system design. These phases can exist within and across organisations, spanning the globe and utilizing an enormous range of information and communication standards. So as to understand the requirements of the predominantly sequential phases, resources are exhausted in converting information into a language which upstream and downstream phases can understand. This research paper aims to reduce this effort by capturing knowledge in a core ontology which is formed by product, process and resource domain ontologies. The vision is that phase or domain experts input information into this ontology, which then infers requirements for the adjacent phases based on predefined relationships. The presented approach permits the insertion of additional information as it becomes available because ontologies are extensible and scalable. This supports a concurrent engineering approach and accommodates the needs of modern businesses. This research paper presents a proof of concept based on a Proton Exchange Membrane Fuel Cell (PEMFC). The rationale for the choice of classes and properties in the model are described. The model is successfully proved by describing liaison precedence and the selection of appropriate assembly equipment.

Providing an access control layer to web-based applications for the industrial domain

The advances in virtual engineering brought about the creation of models of physical systems. This has been enhanced by the use of relevant standards and web technologies to develop interfaces for monitoring and controlling industrial systems at the shop floor or remotely over the internet. However, owing to the open nature of the internet as well as vulnerabilities associated with internet-based technologies, it becomes imperative to put in place security measures. This will allow to mitigate this particularly as it concerns the management, control, and monitoring of entities making use of the interface. The first step is to ensure an efficient user access control for web-based solutions. This article proposes an approach for developing an access control layer to web applications. In addition, a web-based application, i.e., the FASTory simulator, is used as the test-bed for implementing this approach.