Computer-based selection of joining processes

The assembly of any manufactured product involves joining. This paper describes ways of selecting processes for joining. The method allows discrimination of the joint geometry, joint loading, material, and other attributes of the joint itself, identifying the subset of available processes capable of meeting a given set of design constraints. A relational database containing data-tables for joining processes, materials to be joined, and joint geometry and mode of loading, allows the attributes of each of these to be stored in an appropriate format, and permits links to be created between those that are related. A search engine isolates the processes that meet design requirements on material, joint geometry and loading. The method is illustrated in Part 2 by case studies, utilising software that embodies the method.

Fisheries, marine environment, and integrated coastal management policy processes, content and implementation in the BOBLME countries: regional synthesis and country questionnaires

This paper examines policy processes, policy trends and policy implementation with regards to capture fisheries, the marine environment and Integrated Coastal Management (ICM) in BOBLME countries. Individual country information was analyzed to generate a regional synthesis.

Offshore geology of Pakistan and non-living resource prospects

Offshore geology of Pakistan is characterized by active and passive continental margins. These continental margins show very unique features such as an active Makran subduction zone in the west and the Indus delta and a submarine fan in the east. The geology of these features of Pakistan EEZ is inadequately known. This is a major obstacle in exploring mineral resources. Detailed study of coastal and shelf geology is needed for better understanding of the geology of the area and comprehensive evolution of its non-living resource potential. An understanding of the geological events including tectonic movements, sedimentation processes and geochemical history that comprise the geological history is very important to help in identification and estimation of resources. In Pakistan EEZ applying the current technology and undertaking research work to understand the seafloor features and mineral deposits associated with it will be very fruitful.

Impact of sedimentalogical processes on mangrove ecosystem of the Indus Delta

A detailed sedimentalogical study concerning the depletion of mangrove in the Indus Delta due to the marked decrease in the supply of silt was undertaken. Thirty one stations were established for sampling in a selected area of 12000 hectares between Korangi creek and Wad do Khuddi creek. Seventy one samples of soil were collected from 6cm and 1m depth, out of which fifty one samples were selected for sedimentalogical studies. It was inferred from this study that the marine depositional processes are distinctly dominating over the fluvial processes, which is major cause in decreasing the growth of mangrove. It was also inferred that among the sampled stations the sites having clayey silt (with silt 60%-70% and clay 25%-30%) are most favourable for mangrove plantation.

Evaluating the impacts of iteration on PD processes by transforming task network models into System Dynamics models

Iteration is unavoidable in the design process and should be incorporated when planning and managing projects in order to minimize surprises and reduce schedule distortions. However, planning and managing iteration is challenging because the relationships between its causes and effects are complex. Most approaches which use mathematical models to analyze the impact of iteration on the design process focus on a relatively small number of its causes and effects. Therefore, insights derived from these analytical models may not be robust under a broader consideration of potential influencing factors. In this article, we synthesize an explanatory framework which describes the network of causes and effects of iteration identified from the literature, and introduce an analytic approach which combines a task network modeling approach with System Dynamics simulation. Our approach models the network of causes and effects of iteration alongside the process architecture which is required to analyze the impact of iteration on design process performance. We show how this allows managers to assess the impact of changes to process architecture and to management levers which influence iterative behavior, accounting for the fact that these changes can occur simultaneously and can accumulate in non-linear ways. We also discuss how the insights resulting from this analysis can be visualized for easier consumption by project participants not familiar with simulation methods. Copyright © 2010 by ASME.

Data-based robust multiobjective optimization of interconnected processes: energy efficiency case study in papermaking.

Reducing energy consumption is a major challenge for "energy-intensive" industries such as papermaking. A commercially viable energy saving solution is to employ data-based optimization techniques to obtain a set of "optimized" operational settings that satisfy certain performance indices. The difficulties of this are: 1) the problems of this type are inherently multicriteria in the sense that improving one performance index might result in compromising the other important measures; 2) practical systems often exhibit unknown complex dynamics and several interconnections which make the modeling task difficult; and 3) as the models are acquired from the existing historical data, they are valid only locally and extrapolations incorporate risk of increasing process variability. To overcome these difficulties, this paper presents a new decision support system for robust multiobjective optimization of interconnected processes. The plant is first divided into serially connected units to model the process, product quality, energy consumption, and corresponding uncertainty measures. Then multiobjective gradient descent algorithm is used to solve the problem in line with user's preference information. Finally, the optimization results are visualized for analysis and decision making. In practice, if further iterations of the optimization algorithm are considered, validity of the local models must be checked prior to proceeding to further iterations. The method is implemented by a MATLAB-based interactive tool DataExplorer supporting a range of data analysis, modeling, and multiobjective optimization techniques. The proposed approach was tested in two U.K.-based commercial paper mills where the aim was reducing steam consumption and increasing productivity while maintaining the product quality by optimization of vacuum pressures in forming and press sections. The experimental results demonstrate the effectiveness of the method.