Emerald | Journal of Engineering, Design and Technology | Table of Contents

Sedimentation of small and medium sized dams: discussion issues

literatinetwork@emeraldinsight.com (Michael James Tumbare) — Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - There has been a general promotion of small and medium sized dams as the solution to supply water for domestic, sanitation and other livelihood purposes in the less industrialised countries of the world. This Paper seeks to communicate, share ideas and experiences with policy makers and other engineering practitioners in issues related to the sedimentation of, and the development of small and medium sized dams so that relevant issues are taken into account in the planning, design and implementation of such small and medium sized dams. Design/methodology/approach - This Paper, which is a Viewpoint, utilises the findings of various research work carried out in Zimbabwe and findings from other regional and international literature as a basis for discussion and arriving at some engineering and other developmental policy recommendations. The research work utilised and analysed in this Paper is based on actual field work carried out by others as cited. Findings - The Paper concludes that the following policy and technical issues should always be borne in mind in the promotion of small and medium sized dams: • the predicted increase in rainfall intensities due to climate change/variability requires the review of existing small and medium sized dam spillway capacity designs; • an increase in the minimum storage ratios of small and medium sized dams should be made from the current recommended 0.1 to 0.3; • further research work is required to validate the postulation that rainfall intensities are increasing due to the effects of climate change/variability resulting in increased sedimentation of reservoirs; • whilst sediments are required for ecosystem sustenance, they can also be viewed as a pollutant in respect to certain other human water supply needs; • do not build small dams on large catchments as such small dams will silt-up quickly and thereafter pose challenges in the management and disposal of the accumulated sediments and nutrients when decommissioning/rehabilitating them; • every dam site, irrespective of the resultant dam size, should be developed to its maximum potential in respect to the dam site's water yield and/or prevailing topography; • WHO predicts that road traffic injuries will rise to become the fifth leading cause of death by 2030. The "vulnerable road users" and/or their estates should also receive like attention and timely compensation benefits as advocated for the large dam's "disadvantaged and vulnerable" people. Originality/value - Every year, about 1% of the world’s reservoir capacities are lost to sedimentation (Howard, 2000). Most researchers postulate that an increase in the intensity of rainfall due to climate change/variability is imminent and will result in increased sediment loads with resultant negative impacts on dam reservoir life-spans and usefulness (SADC, 2011). This Paper discusses the advantages, disadvantages and efficiency of small and medium sized dams in satisfying the various beneficiary needs in the less industrialised countries of the world. The technical issues that have to be considered in the design and construction of such small and medium sized dams in order to minimise the negative impacts of sedimentation in their development are also presented and discussed. The opinions and conclusions drawn in the viewpoint are those of the author.

Development of Value Stream Map for achieving leanness in a manufacturing organization

literatinetwork@emeraldinsight.com (Sekar Vinodh, Somanaathan M, Arvind KR) — Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - To explore the practical feasibility of deploying Value Stream Mapping (VSM) for enabling lean manufacturing. Design/methodology/approach - The literature on lean manufacturing and VSM has been reviewed. VSM has been selected as a technique for solving the problem existing in the case organization. The current state map has been developed after making necessary observations and calculations. Then various improvement proposals have been identified and the future state map has been developed. The simulation approach has been used for validating performance improvements. The practicality of the approach has been validated. Findings - Two kinds of validation are being conducted in the case organization using questionnaire based approach. In the first stage, the practical receptivity of deploying the proposals has been gathered from the executives. In the second stage, statistical validation has been performed.Research limitations/implications - VSM has been applied for solving the problem in the case organisation. But the organisation has implemented world class strategies such as ISO Quality Management System and Total Quality Management. Hence, the experiences gained by the conduct of this implementation study are feasible and deployable in similar organisations. Practical implications - In order to acquire lean characteristics, modern organisations are focussed on the test implementation of various lean tools. The results of the implementation study indicated significant improvement in lean characteristics. Originality/value - The implementation study reported in this article is an original contribution of the authors which has been conducted in a typical industrial scenario. By the virtue of its research background and practical compatibility, the implementation study is considered to be highly valuable.

The Effect of Maintenance on the Survival of Medical Equipment

Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - Studying the availability of medical equipment based on various maintenance types has been a major concern for hospitals. Most of the methodologies used are empirical and few are based on mathematical modelling. The objective of this paper is to present a mathematical maintenance model that analyses the effect of maintenance on the survival probability of medical equipment based on maintenance history and age of that equipment. Design/methodology/approach - A global model is proposed to measure the probability of equipment being available using real data extracted from maintenance history of infusion pumps and ventilators and analysed using Matlab. To confirm the validity of the developed model, the survival analysis approach is used to develop a model that measures the survival of equipment as a function of maintenance and age of equipment. The method is first tested using simulated data and the findings confirm the validity of the proposed approach.Findings - The analysis using survival approach reveals that conducting preventive maintenance on the selected medical equipment had an impact on survival of equipment. However, the manufacturer’s recommended PM intervals do not correlate to the failure rate encountered. This will contribute to the debate on preventive maintenance manufacturer’s recommended intervals and might lead to the revision of maintenance strategies implemented by hospitals and clinical engineering practitioners. Research limitations/implications - Although the data collected for the infusion pumps was quite sufficient, that collected for the ventilators was more limited. The major difficulty is that of the availability of historical maintenance data and the effect of user errors may cause uncertainty in the analysis. A closer collaboration with the medical professional should facilitate the recording and access to such informationPractical implications - The use of mathematical modelling to analyse the effect of maintenance on the survival of medical equipment is a beneficial tool that is not exploited in the medical equipment industry. It will provide clinical engineering practitioners with scientific tool to analyse the effect of preventive maintenance on the survival of medical equipment.Originality/value - This paper presents a mathematical approach to analyse the effect of maintenance on the survival of medical equipment, which is crucial in the assessment of maintenance strategies implemented in the medical equipment industry.

Design and Analysis of a Novel Earpiece-less Eyeglass Frame

literatinetwork@emeraldinsight.com (Byron Griffin, James Yang) — Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - Conventional eye-glasses exhibit many problems including poor comfort levels amongst different users and easy to break leg hinges. This paper will present the detailed design and analysis procedure of a novel earpiece-less eyeglass frame Design/methodology/approach - The newly design frame includes the female joint, spring, and stemed-ball which make up the complete sliding ball joint and analysis of female joint, spring and stem-ball to ensure the idea durability and usability.Findings - Earpiece-less eyeglasses are easier to adjust for higher comfort levels and do not incorporate leg hinges. Originality/value - The earpiece-less eyeglasses is a novel design and this concept is unique.

An Integrated Design Approach for Rapid Product Development: A Case Study through Application of Reverse Engineering, Re-engineering and Fast Prototyping Tools

Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - The purpose of this paper is to present an integrated design approach for rapid product development of a broken product. Design/methodology/approach - Reverse engineering (RE), re-engineering (ReE) and rapid product development (RpD) systems have been incorporated to infuse agile characteristics in the proposed design and development process. A case study involving a broken clutch shoe was selected to demonstrate the efficacy of the proposed integrated approach.Findings - Integration of RE, ReE and RpD presented an unconventional approach towards achieving reduced lead times for design and development of products. Agile characteristics have been manifested for the broken clutch shoe by retrieval of a digitized parametric CAD model. Moreover, development and selection of an enhanced feasible design (M3) as well as delivery of the corresponding prototype was accomplished just in one week. Originality/value - The proposed integrated approach for RpD can provide solutions to similar industrial situations wherein agility in the product design and development process can be infused so that the developed part can be delivered quickly to the customer at the reduced time and costs.

BIM Collaboration in Student Architectural Technologist Learning

literatinetwork@emeraldinsight.com (Malachy Mathews) — Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - This paper is the result of a qualitative case study which investigated the influence of building information modelling (BIM) collaboration on the learning of student architectural technologists based around a studio group project. The purpose of the paper is to disseminate knowledge gained into a new learning environment facilitated by the collaborative properties of a BIM application. Design/methodology/approach - A qualitative case study approach has been used to undertake the examination of the learner’s experiences during the project. This approach allowed the author to map the complex interaction between the participants during the stages of the collaborative design project. Findings - The complexities of modern design and construction lead the author conclude that no one profession has all the answers to all the questions. New processes bring new responsibilities. The amount of specialised expertise that goes into a modern building expands constantly. This new collaborative learning environment simulated through working with BIM has the potential to prepare and equip the student architectural technologist with the skill-set to be at the centre of the problem solving collaborative process.Research limitations/implications - The research was carried out on one group consisting of six student architectural technologists working with one practising architect over a twelve week period. The author was the single observer to the project. Practical implications - This paper will support higher education institutions proposing to introduce collaborative BIM applications into a built environment curriculum and also may act as a catalyst to encourage educators to adopt a similar approach to teaching in a range of other professions.Originality/value - This paper identifies a potential for higher level learning facilitated by collaborative BIM technologies and methodologies. It also supports the need in higher education to provide for transition from theory to workplace practice.

A comparative study on static properties of a three-main-truss and three-cable-plane cable-stayed bridge

literatinetwork@emeraldinsight.com (Pengfei Zheng, Gonglian Dai) — Fri, 05 Jul 2013 00:00:00 +0100

Abstract

Purpose - Aiming to obtain the further and overall generation about the static characteristics of the structure for the better application of the structure.Design/methodology/approach - Through nonlinear finite element simulation, serials of comparative analyses are performed on this structure and other three assumed structures, which illustrates the effect the main part of the structure on the structural static properties. Meanwhile, adopting the first order method, spatial cable force optimization makes the structural mechanic more rational.Findings - Under same level stress, this three-main-truss and three-cable-plane bridge could save almost 38.8% vertical chords materials consumption at least; In contrast, this bridge has a lower lateral torsional stiffness, considering the key to raise the lateral and torsional stiffness is enhancing axial stiffness of plane bracing, the suitable plane bracing members area is twice as the original area; After rational optimization, the cable tension ratio between the mid-cable plane and the two side-cable planes is range from 1.09 to 1.14.Research limitations/implications - The work in this paper of the comparative analyis could give other engineers a way to a deep analyis method for the structural analysis, especially in civil engineering. Practical implications - The conclusions would provide other designers some applied advice.Originality/value - The study illustrates the structural static properties of the structure more clearly for engineers, while proposes some rational design consults for designers originally.