42 resultados para Manufacturing processes.


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Quickstep✹ is a novel technology for composite materials manufacturing. Characterisation of carbon fibre reinforced polymer composites cured both conventionally and with the low cost Quickstep process revealed a higher glass transition temperature, enhanced fracture toughness and better impact resistance for the Quickstep composite laminates.

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Melding is a new approach to joining advanced composite materials and components. The research focused on characterizing the nature of composite materials joined by the melding process. The outcomes of the thesis demonstrate that melding produces joints that are equivalent to monolithic material.

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This research has enhanced the performance of natural fibre composites by optimisation of the cure cycle under Quickstep{u2122} process and treatment time under atmospheric pressure glow discharge plasma. The study has also utilised many characterization methods, theoretical models, and established surface-property relationship to manufacture composites with optimum strength and toughness.

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Identification of unnatural control chart patterns (CCPs) from manufacturing process measurements is a critical task in quality control as these patterns indicate that the manufacturing process is out-of-control. Recently, there have been numerous efforts in developing pattern recognition and classification methods based on artificial neural network to automatically recognize unnatural patterns. Most of them assume that a single type of unnatural pattern exists in process data. Due to this restrictive assumption, severe performance degradations are observed in these methods when unnatural concurrent CCPs present in process data. To address this problem, this paper proposes a novel approach based on singular spectrum analysis (SSA) and learning vector quantization network to identify concurrent CCPs. The main advantage of the proposed method is that it can be applied to the identification of concurrent CCPs in univariate manufacturing processes. Moreover, there are no permutation and scaling ambiguities in the CCPs recovered by the SSA. These desirable features make the proposed algorithm an attractive alternative for the identification of concurrent CCPs. Computer simulations and a real application for aluminium smelting processes confirm the superior performance of proposed algorithm for sets of typical concurrent CCPs.

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Optical inspection techniques have been widely used in industry as they are non-destructive. Since defect patterns are rooted from the manufacturing processes in semiconductor industry, efficient and effective defect detection and pattern recognition algorithms are in great demand to find out closely related causes. Modifying the manufacturing processes can eliminate defects, and thus to improve the yield. Defect patterns such as rings, semicircles, scratches, and clusters are the most common defects in the semiconductor industry. Conventional methods cannot identify two scale-variant or shift-variant or rotation-variant defect patterns, which in fact belong to the same failure causes. To address these problems, a new approach is proposed in this paper to detect these defect patterns in noisy images. First, a novel scheme is developed to simulate datasets of these 4 patterns for classifiers' training and testing. Second, for real optical images, a series of image processing operations have been applied in the detection stage of our method. In the identification stage, defects are resized and then identified by the trained support vector machine. Adaptive resonance theory network 1 is also implemented for comparisons. Classification results of both simulated data and real noisy raw data show the effectiveness of our method.

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Aims This paper describes the refinement and adaptation to small business of a previously developed method for systematically prioritizing needs for intervention on hazardous substance exposures in manufacturing worksites, and evaluating intervention effectiveness. Methods We developed a checklist containing six unique sets of yes/no variables organized in a 2 × 3 matrix of exposure potential versus exposure protection at three levels corresponding to a simplified hierarchy of controls: materials, processes, and human interface. Each of the six sets of indicator variables was reduced to a high/moderate/low rating. Ratings from the matrix were then combined to generate an exposure prevention 'Small Business Exposure Index' (SBEI) Summary score for each area. Reflecting the hierarchy of controls, material factors were weighted highest, followed by process, and then human interface. The checklist administered by an industrial hygienist during walk-through inspection (N = 149 manufacturing processes/areas in 25 small to medium-sized manufacturing worksites). One area or process per manufacturing department was assessed and rated. A second hygienist independently assessed 36 areas to evaluate inter-rater reliability. Results The SBEI Summary scores indicated that exposures were well controlled in the majority of areas assessed (58% with rating of 1 or 2 on a 6-point scale), that there was some room for improvement in roughly one-third of areas (31% of areas rated 3 or 4), and that roughly 10% of the areas assessed were urgently in need of intervention (rated as 5 or 6). Inter-rater reliability of EP ratings was good to excellent (e.g., for SBEI Summary scores, weighted kappa = 0.73, 95% CI 0.52–0.93). Conclusion The SBEI exposure prevention rating method is suitable for use in small/medium enterprises, has good discriminatory power and reliability, offers an inexpensive method for intervention needs assessment and effectiveness evaluation, and complements quantitative exposure assessment with an upstream prevention focus.

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Polypyrrole is a material with immensely useful properties suitable for a wide range of electrochemical applications, but its development has been hindered by cumbersome manufacturing processes. Here we show that a simple modification to the standard electrochemical polymerization method produces polypyrrole films of equivalently high conductivity and superior mechanical properties in one-tenth of the polymerization time. Preparing the film as a series of electrodeposited layers with thorough solvent washing between layering was found to produce excellent quality films even when layer deposition was accelerated by high current. The washing step between the sequentially polymerized layers altered the deposition mechanism, eliminating the typical dendritic growth and generating nonporous deposits. Solvent washing was shown to reduce the concentration of oligomeric species in the near-electrode region and hinder the three-dimensional growth mechanism that occurs by deposition of secondary particles from solution. As artificial muscles, the high density sequentially polymerized films produced the highest mechanical work output yet reported for polypyrrole actuators.

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Factories of the Future will be distinguished by intelligent machines, automation, human factors integration and knowledge management. Modelling and simulation is recognised as a key enabling technology essential to economic, social and environmental sustainability of future manufacturing systems. This talk will explore the history, recent achievements and directions in modelling and simulation for 21st century factories and supply chains. A systems science approach is employed, from stakeholder engagement through participative modelling to self-tuning and self-assembling simulations. Our contributions lower the cost of the application of modelling and simulation to manufacturing processes, enabling real time planning, dynamic risk analysis, dashboards and 3D visualisation. This realisation of the virtual factory integrates human factors and decisions into the core technology platform. The implications to future manufacturing enterprises are explored through a series of case studies from aerospace, mining and small and medium manufacturing enterprises.

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This article describes a new method for (1) systematically prioritizing needs for intervention on hazardous substance exposures in manufacturing work sites, and (2) evaluating intervention effectiveness. We developed a checklist containing six unique sets of yes/no variables organized in a 2 × 3 matrix of exposure potential versus protection (two columns) at the levels of materials, processes, and human interface (three rows). The three levels correspond to a simplified hierarchy of controls. Each of the six sets of indicator variables was reduced to a high/moderate/low rating. Ratings from the matrix were then combined to generate a single overall exposure prevention rating for each area. Reflecting the hierarchy of controls, material factors were weighted highest, followed by process, and then human interface. The checklist was filled out by an industrial hygienist while conducting a walk-through inspection (N = 131 manufacturing processes/areas in 17 large work sites). One area or process per manufacturing department was assessed and rated. Based on the resulting Exposure Prevention ratings, we concluded that exposures were well controlled in the majority of areas assessed (64% with rating of 1 or 2 on a 6-point scale), that there is some room for improvement in 26 percent of areas (rating of 3 or 4), and that roughly 10 percent of the areas assessed are urgently in need of intervention (rated as 5 or 6). A second hygienist independently assessed a subset of areas to evaluate inter-rater reliability. The reliability of the overall exposure prevention ratings was excellent (weighted kappa = 0.84). The rating scheme has good discriminatory power and reliability and shows promise as a broadly applicable and inexpensive tool for intervention needs assessment and effectiveness evaluation. Validation studies are needed as a next step. This assessment method complements quantitative exposure assessment with an upstream prevention focus.

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The management of a firm's green operations is increasingly important for marketing strategists. The purpose of this study is to investigate the cross-influences of green marketing strategy and the key internal green functional areas in a firm. We use the antecedents of marketing strategy and identify relationships between green marketing strategy and key supporting internal environmental operations of firms with respect to (1) green suppliers, (2) environmental resource management, (3) green research and development, and (4) environmental manufacturing processes and procedures. The statistical techniques of parallel analysis, factor analysis and multiple regressions are used to analyze data collected from 332 firms. The results identify that among the four functional areas of firms adopting green marketing strategy. Two are more likely to influence green marketing strategy – supplier selection and research and development. Implications are discussed. The findings contribute to the theory of green marketing strategy. Future research is recommended.

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The management of a firm's green operations is increasingly important for marketing strategists. The purpose of this study is to investigate the cross-influences of green marketing strategy and the key internal green functional areas in a firm. We use the antecedents of marketing strategy and identify relationships between green marketing strategy and key supporting internal environmental operations of firms with respect to (1) green suppliers, (2) environmental resource management, (3) green research and development, and (4) environmental manufacturing processes and procedures. The statistical techniques of parallel analysis, factor analysis and multiple regressions are used to analyze data collected from 332 firms. The results identify that among the four functional areas of firms adopting green marketing strategy. Two are more likely to influence green marketing strategy – supplier selection and research and development. Implications are discussed. The findings contribute to the theory of green marketing strategy. Future research is recommended.

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This chapter presents the fundamentals of “green” marketing by drawing on traditional marketing theory as well as researchfocused on green marketing context. It discusses five critical areas in green marketing. The first critical area stems from green marketingtheory and practice that examines the logic for reducing the environmental impact of value creation and exchange. The second criticalarea highlights green marketing strategy that focuses on achieving organizational goals in ways that can reduce or eliminate negativeimpacts on the natural environment. The third critical area examines the green marketing mix that accounts for green products, greendistribution, green pricing, and green promotion. By using traditional marketing concepts, the chapter identifies how the entiremarketing mix elements should consistently provide a complete green product offering. Green products and processes need to beresearched, designed, and manufactured to include environmentally safe ingredients and components. Products need to be strategicallypriced to reflect their green values, distributed in the green chain channels and displayed effectively to highlight their status, and accuratelycommunicated to consumers and stakeholders. The fourth critical area illustrates governance and control. It shows how theholistic transformation toward greening the organization requires organizational culture change to gain support within and outside thefirm to ensure environmental issues are appropriately considered. These can be assessed by using existing management mechanisms,such as environmental management systems and/or triple bottom line management, which ensure best practice and continuousimprovements to occur. Lastly, the chapter discusses the future of green marketing and the direction that businesses need to take if theyseek to be sustainable.

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This paper presents a new multivariate process capability index (MPCI) which is based on the principal component analysis (PCA) and is dependent on a parameter (Formula presented.) which can take on any real number. This MPCI generalises some existing multivariate indices based on PCA proposed by several authors when (Formula presented.) or (Formula presented.). One of the key contributions of this paper is to show that there is a direct correspondence between this MPCI and process yield for a unique value of (Formula presented.). This result is used to establish a relationship between the capability status of the process and to show that under some mild conditions, the estimators of this MPCI is consistent and converge to a normal distribution. This is then applied to perform tests of statistical hypotheses and in determining sample sizes. Several numerical examples are presented with the objective of illustrating the procedures and demonstrating how they can be applied to determine the viability and capacity of different manufacturing processes.

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Ti and Ti-based alloys have unique properties such as high strength, low density and excellent corrosion resistance. These properties are essential for the manufacture of lightweight and high strength components for biomedical applications. In this paper, Ti properties such as metallurgy, mechanical properties, surface modification, corrosion resistance, biocompatibility and osseointegration in biomedical applications have been discussed. This paper also analyses the advantages and disadvantages of various Ti manufacturing processes for biomedical applications such as casting, powder metallurgy, cold and hot working, machining, laser engineering net shaping (LEN), superplastic forming, forging and ring rolling. The contributions of this research are twofold, firstly scrutinizing the behaviour of Ti and Ti-based alloys in-vivo and in-vitro experiments in biomedical applications to determine the factors leading to failure, and secondly strategies to achieve desired properties essential to improving the quality of patient outcomes after receiving surgical implants. Future research will be directed toward manufacturing of Ti for medical applications by improving the production process, for example using optimal design approaches in additive manufacturing and investigating alloys containing other materials in order to obtain better medical and mechanical characteristics.

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Food protein-derived bioactive peptides (BPs) have been reported to trigger certain physiological responses in the body, thereby influencing health positively. These peptides have attracted high research and consumer interests due to their huge potential of use in functional foods and other dietary interventions of disease control and health promotion. However, successful product development is limited by the fact that current manufacturing processes are either difficult to scale up, high in cost, or have the potential to affect the structure-activity properties of these peptides. To overcome these challenges, we have proposed in this review, the use of an integrated ‘-omics’ approach comprising in silico analysis and ‘-omics’ techniques (such as peptidomics) to respectively forecast and validate the biological and physico-chemical properties of the peptides. This information is then used for the rational design of suitable purification steps for peptides of interest. Downstream purification could also be undertaken by liquid chromatography using monolithic adsorbents physico-chemically engineered (using results of in silico analysis) for rapid isolation of peptides. By coupling the high throughput and predictive capability of ‘-omics’ to the enhanced convective hydrodynamics of monolithic columns, it becomes feasible, even at preparative scale, to produce BPs that meet the requirements of high purity, potency, and cost-effectiveness.