Advances in stationary and portable fuel cell applications

The reliance on fossil fuels is one of the most challenging problems that need to be dealt with vigorously in recent times. This is because using them is not sustainable and leads to serious environmental issues, such as: air pollution and global warming. This condition affects economic security and development. An alternative to fossil fuel is highly possible which will be more environmentally friendly, sustainable and efficient as well. Among all the different technologies associated with renewable energy, fuel cell technologies represent one of the most promising technological advancement to curb the situation. In this paper, an overview of the technology and its advantages and disadvantages compared with competitive technologies was revealed. The application of different fuel cell types in the stationary and portable sectors was covered. Furthermore, recent challenges and promising developments of current fuel cell technologies in different studied applications were reviewed. Some possible solutions to the challenges were named in this paper for both the portable and stationary fuel cell applications. The paper further seeks to expose the world to the current progress made in the fuel cell industry up to date and possible areas that needs intensified research and modifications to make the fuel cell industry more vibrant and buoyant

Evalaution and optimization of laser cutting parameters for plywood materials

Laser process parameters influence greatly the width of kerfs and quality of the cut edges. This article reports experiments on the laser plywood-cutting performance of a CW 1.5 kW CO2¬ Rofin laser, based on design of experiments (DOE). The laser was used to cut three thicknesses 3, 6 and 9 mm of plywood panels. The process factors investigated are: laser power, cutting speed, air pressure and focal point position. The aim of this work is to relate the cutting edge quality parameters namely: upper kerf (UK), lower kerf (LK), the ratio between upper to lower kerfs and the operating cost to the process parameters mentioned above. Mathematical models were developed to establish the relationship between the process parameters and the edge quality parameters, and special graphs were drawn for this purpose. Finally, a numerical optimization was performed to find out the optimal process setting at which both kerfs would lead to a ratio of about 1, and at which low cutting cost take place

Methods of measuring residual stresses in components

Residual stresses occur in many manufactured structures and components. Large number of investigations have been carried out to study this phenomenon and its effect on the mechanical characteristics of these components. Over the years, different methods have been developed to measure residual stress for different types of components in order to obtain reliable assessment. The various specific methods have evolved over several decades and their practical applications have greatly benefited from the development of complementary technologies, notably in material cutting, full-field deformation measurement techniques, numerical methods and computing power. These complementary technologies have stimulated advances not only in measurement accuracy and reliability, but also in range of application; much greater detail in residual stresses measurement is now available. This paper aims to classify the different residual stresses measurement methods and to provide an overview of some of the recent advances in this area to help researchers on selecting their techniques among destructive, semi destructive and non destructive techniques depends on their application and the availabilities of those techniques. For each method scope, physical limitation, advantages and disadvantages are summarized. In the end this paper indicates some promising directions for future developments

Measurement planning based on manufacturing process

In planning the coordinate measuring machine based inspection of a mechanical component feature, cleverness may be added with the definition of an empirical model representing the “signature” left by the process the feature went through. This paper focuses on two industrial related case studies and shows the benefits in terms of inspection costs reduction due to a proper selection of measuring points number and position. A new approach in tolerance evaluation based on process’ signature rebuilding is also proposed

The interoperability of exergy and Life Cycle Thinking in assessing manufacturing sustainability: A review of hybrid approaches

Today, the Life Cycle Assessment (LCA) is the most employed tool for assessing the sustainability of products and processes, both from an environmental, social and economic point of view. Exergy is defined by literature as the amount of useful work that can be derived from a real system when it is brought into equilibrium with its environment. In the literature, it is considered an outstanding concept that can be applied to enhance the effectiveness of ordinary evaluation models such as LCA. The literature proposes a variety of hybrid approaches that combine Exergetic Analysis (EA) and LCA with different combination frameworks. The aim of this paper is to describe the potential of each hybrid method and to characterize the degree of interoperability between EA and LCA that each of them can provide. Nevertheless, there are drawbacks that seem to be too challenging to overcome: a variety of inconsistencies in the interpretation of the results due to the difficulty of the inventory phase and the ambiguity in the choice of the correct alternative in the standard databases; the link with old techniques that refers to obsolete approaches in finding data that suit to the updated goals and scopes; the difficulty in conducting an assessment affected by the least possible uncertainty. Following a theoretical overview of the principles of each hybrid method that binds EA and LCA, the authors want to provide a review from a completely different point of view than the state-of-the-art literature, on how effectively EA and LCA can interact with each other in order to provide a more holistic view of the system/process to be assessed. The fascinating circumstance that emerges from the review is that any exergy approach would be more effective if joined (not replaced) to the standard LCA, because it turned out to be complementary. This theory has long been developed by many authors in their case studies as a confirmation of what Gutowski wrote years ago: no single alternative criteria or subsidiary model, independently of how well aggregated, may offer a suitable answer for all conditions. Specifically, through this review, the practitioners would be able to choose the best suited hybrid methodology, according to their aims, join the outcomes together and achieve a transdisciplinary knowledge of the behavior of the study case system, in order to design the best improvement strategies

Manufacturing Signature and CMM-based Inspection

Invited Speaker at the Conference on Measurements and Uncertainty Evaluation in Coordinate Measuring Machine (CMM) and Scanners and their Implication on Design and Reverse Engineerin

Measurement Planning Based On Manufacturing Process

In planning the coordinate measuring machine based inspection of a mechanical component feature, cleverness may be added with the definition of an empirical model representing the “signature” left by the process the feature went through. This paper focuses on two industrial related case studies and shows the benefits in terms of inspection costs reduction due to a proper selection of measuring points number and position. A new approach in tolerance evaluation based on process’ signature rebuilding is also proposed

Progress of tool condition monitoring in drilling

The capability of drill status monitoring has a strong economic potential, since large benefits can be obtained when exploiting tools up to their real end-of-life; this can be done once the decay mechanism is clearly defined and understood. A large amount of research activities has been devoted so far in the last decades, particularly for drilling operations, since tool management, usually, relies on a conservative evaluation of tool-life, because of the empirical approach in evaluating the effects of failure mechanisms bringing to sudden failures or decay; this fact leads to an unnecessarily high number of changes and to increase of cost impacts. For this reasons, particularly in automated production systems, efforts in research should be devoted on the measurement of drill-status, which reflects directly on surface features and indirectly on the quality of the holes manufactured. This paper presents a benchmark of a large number of existing drill-decay measurement techniques (DDMT) proposed so far in scientific papers and contributions, providing an up-to-date analysis of main factors which characterized the applicability of DDMT to automated production systems as well as the pro and cons of principal technologies available. The outcome of the work is thus a technical requirement specification useful to provide new hints for realising a reliable wear monitoring system for drilling operations, potentially applicable to automated production system

Technologies and developments of third generation biofuel production

Many authorities have reached the conclusion that using fossil fuels, as the main source of energy to satisfy the increasing global energy demand, is ultimately unsustainable. This is because of depleting resources, and also because, if this approach is followed, emissions of carbon dioxide would continue to build up. Consequently, research on biofuel, that is fuel made from biomass, derived from materials that were recently living, has attracted attention. In this context, the generation of biofuels from algae shows promise for the following reasons. The algae can be grown quickly, all the materials produced are non-toxic and biodegradable, and during this growth there is an opportunity to cause greenhouse gas fixation. Also, since growing algae does not need arable land, it can be grown without competing with food or feed crops, the fuel derived from it being a “third generation” biofuel. This paper describes different types of algae (microalgae and seaweeds), and presents different technologies employed in making biofuels (biogas and biodiesel) from them