bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the multi‐manipulator tooth‐arrangement robot for complete denture manufacturing
Authors: Yong‐de Zhang , Jin‐gang Jiang , Pei‐jun Lv , Yong Wang
Published: December 2010

Purpose

It is not an easy and simple task to manufacture a complete denture with high quality. Traditionally, it often needs a medical expert with experience and hand‐on skill, due to the manual way of denture manufacturing. The purpose of this paper is to implement the multi‐manipulator tooth‐arrangement robot system that can fully automate the denture manufacturing process.

Design/methodology/approach

A novel complete denture manufacturing mechanism is designed, which is based on the multi‐manipulator and dental arch generator. The visual tooth‐arrangement and robot control software is developed in VC++6.0. Preliminary experiments on tooth‐arrangement have been conducted using the proposed multi‐manipulator tooth‐arrangement robot prototype system.

Findings

The multi‐manipulator tooth‐arrangement robot prototype system can automatically design and manufacture a set of complete denture that fit a patient by visual tooth‐arrangement and robot control software according to the patient's jaw arch parameters.

Research limitations/implications

The implication of research is that it is feasible that the manufacture strategy of complete denture fulfilled by multi‐manipulator tooth‐arrangement robot. The limitation of research is that it is difficult to realize coordinate control.

Originality/value

The traditional manual method which makes complete denture by medical personal experience will be changed after the multi‐manipulator tooth‐arrangement robot system is manufactured, and adjustment to each tooth position and orientation will be realized by this system.
Automatic planning and coordinated control for redundant dual‐arm space robot system
Authors: Zhou Jun , Ding Xilun , Yue Qing Yu
Published: December 2010

Purpose

The purpose of this paper is to present a novel automatic planning and coordinated control method of redundant dual‐arm space robot for inner space‐station operation based on multiple sensors information by stages.

Design/methodology/approach

In order to improve the coordinated control capability of dual‐arm robot system, a four‐layer hierarchical control structure is designed based on the theory of centralization and decentralization. At the high‐level planning of dual‐arm system, a task decomposition strategy based on task knowledge and a task allocation strategy in terms of the robotic capability are proposed, respectively. Moreover, a control method by stages based on the information of multiple sensors is introduced to object recognition, task planning, path planning and trajectory planning. Finally, a 3D simulation and experiment of screwing nut and bolt are implemented on a dual‐arm robot system, and the feasibility and applicability of this control strategy are verified.

Findings

The automatic planning can be accomplished by means of sensors information by stages, and by this method, the autonomy and intelligence of dual‐arm space robot system can be further improved.

Practical implications

A new automatic planning strategy integrated with multiple sensors information by stages is proposed, and can be implemented on a dual‐arm robot system for inner space‐station operations. This method specializes in heterogeneous dual‐arm robot system.

Originality/value

A task decomposition strategy based on task knowledge and a task allocation strategy in terms of the robotic capability are proposed, respectively. Moreover, a control method by stages based on the information of multiple sensors is introduced to object recognition, task planning, path planning and trajectory planning of dual‐arm robot system.
Robotic edge profiling of complex components
Authors: Jayaweera Nirosh , Webb Phil
Published: December 2010

Purpose

This paper aims to describe the development and testing of a system for the automated deburring of aero‐engine components.

Design/methodology/approach

The system described in this paper uses an in‐process measurement sensor to determine the component's exact location prior to the deburring operation. The core of the system is a set of algorithms capable of fitting and generating the required robot path relative to the feature to be profiled.

Findings

The paper demonstrates that with a combination of non‐contact metrology and mathematical processing standard industrial robot can be used to deburr aero engine components.

Originality/value

The paper introduces an efficient robotic deburring method, which is developed based on generating real‐time robotic deburring path. Reducing the reliance on part holding fixtures and the use of a laser‐guided robot ensures the developed deburring system is highly flexible and re‐configurable.
Implementation of a single motor driven manipulator with multiple joints
Authors: Li Shiqi , Liu Yang , Xie Ming
Published: December 2010

Purpose

The purpose of this paper is to present the design and implementation of a new manipulator with six joints driven by a single DC motor.

Design/methodology/approach

The manipulator consists of several modules, each of which has the twisting and pivoting degrees of freedom. Two clutches and one brake are mounted to control each joint. A clutch model based on PWM control is built to compute the average velocity of each clutch. Two parameters are involved in the model: PWM frequency and duty ratio. PWM frequency is limited by the natural frequencies of structure with all postures. The theoretical duty ratio should be adjusted according to the clutch model. Two experiments – line tracking and arc tracking – are carried out to verify the effectiveness of the control system.

Findings

The study has designed a manipulator with six joints driven by a single DC motor which powers all the modules through a main shaft and several clutches. In the manipulator, all the modules are supplied with a constant speed input and provide a bi‐directional variable output. Experimental results show the clutch model built for the manipulator can be applied to the joint control of all multi‐joint manipulators.

Originality/value

The paper describes a dexterous and light‐weight manipulator driven by a single motor and designed with bi‐directional joints.
Application of service robots for building NDT inspection tasks
Authors: Liu K.P. , Luk B.L. , Tong F. , Chan Y.T.
Published: December 2010

Purpose

Building inspection tasks usually involve working at life‐threatening height, especially for high‐rise buildings. The purpose of this paper is to introduce two service robots which are designed for high‐rise building inspection applications.

Design/methodology/approach

The first service robot, equipped with independent‐climbing capability, is applied to gas pipe inspection. The robot requires very little setup time and is suitable for some small inspection tasks. The second, which shares some similarities of industrial gondolas, is applied to check the health conditions of tile‐walls of high‐rise buildings. This robot requires more initial setup time but can provide faster inspection operations. In addition, it can be programmed to carry out the inspection task automatically. So, it is more suitable for large‐scale inspection tasks.

Findings

For tile‐wall inspection, a fast, low‐cost and effective non‐destructive testing technique based on impact acoustic method has been developed for the robot.

Originality/value

Both prototypes have been applied to housing estates for evaluation purposes.
Feature‐fusion based object tracking for robot platforms
Authors: Zhang Xuguang , Liu Honghai , Wang Yanjie
Published: December 2010

Purpose

Object tracking has been a challenging problem of robot vision over the decades, which plays a key role in a wide spectrum of visual tracking‐related applications such as surveillance, visual servoing, sensing and navigation in robotics, video compression. The purpose of this paper is to present a novel intensity, orientation codes and geometry (IOCG) histogram variant of the mean‐shift algorithm for object tracking.

Design/methodology/approach

Feature cues of intensity, orientation codes and geometric information are fused together to form an IOCG histogram in combination with a conventional mean‐shift‐based tracking algorithm.

Findings

Experimental results demonstrate the effectiveness and efficiency of the proposed method. Not only do fusing orientation codes features allow the proposed algorithm to conduct tracking in a cluttered background, but partial occlusion is also solved in the tracker in that spatial information usually lost in a conventional histogram is compensated by the introduced geometric relations between tracked pixels and the center of a tracker template.

Originality/value

The paper presents a novel vision tracking method for robots.
Modeling of self‐tilt‐up motion for a two‐wheeled inverted pendulum
Authors: Miao Shouhong , Cao Qixin
Published: December 2010

Purpose

The purpose of this paper is to present a two‐wheeled inverted pendulum with self‐tilt‐up motion ability. With this ability, the two‐wheeled inverted pendulum can erect without assistance, and then the vehicle can be autonomously deployed. The paper proposes an approach to achieve this self‐tilt‐up motion, which involves precessional motion.

Design/methodology/approach

A flywheel is mounted inside the vehicle to perform high‐speed spinning. The flywheel and body of the vehicle are forced to move around a fixed point and precessional motion occurs. As a result of the precessional motion, a moment is synchronously generated to tilt the body up to the upright position. Since no external force is applied on this two‐wheeled inverted pendulum, it is called self‐tilt‐up motion. A 3D model and a prototype are built to validate this approach.

Findings

The simulation and experimental results show that the self‐tilting‐up motion is successful.

Research limitations/implications

This paper presents a self‐tilt‐up motion for a two‐wheeled inverted pendulum. With the analysis of the dynamics, simulation demonstrations and prototype development, the results show that the vehicle could perform self‐tilt‐up motion without any assistance. The principle of this self‐tilt‐up motion involves processional motion of rigid body. We also pointed out the factors that play important roles in influencing the performance of self‐tilt‐up motion and then define the switching time for the motion to switch to dynamic balance movement.

Originality/value

Traditional multi‐wheel robots cannot work when they overturn. However, the two‐wheeled inverted pendulums with self‐tilt‐up ability do not have this shortcoming. They can stand up to keep working even if they fall down. A two‐wheeled inverted pendulum with self‐tilt‐up ability can be applied to many places. Equipped with solar battery, it can be used as an independent explorer. This type of vehicle can be deployed in swarms for planetary detection. For example, many small two‐wheeled inverted pendulums assist a lunar rover for exploration, samples gathering, etc.
Case‐based automatic programming in robotic assembly production
Authors: Wang Lei , Tian Yajie , Sawaragi Tetsuo
Published: December 2010

Purpose

The purpose of this paper is to present a case‐based system for offline automatic programming in robotic assembly production. This system can reuse past learned robot programs to generate programs for new assembly tasks.

Design/methodology/approach

The approach used in this paper is case‐based reasoning. The assembly knowledge acquired from the robot program for an assembly task is retained in a case, which is composed of the primitive task description and the corresponding robot program schema. The retained cases are retrieved by matching features of their primitive task descriptions, and are reused to automatically program for new tasks by instantiating their robot program schemata.

Findings

A case not only can be reused as a whole, but also can be reused partly by synthesizing different parts of several cases to generate a program for a new task in a variant environment.

Practical implications

The teaching time of robots can be greatly reduced. This helps to introduce robots into small and medium enterprises.

Originality/value

This paper proposes a novel system that can automatically program for assembly tasks in various environments by flexibly reusing past robot programs.
Employment situation of women in Pakistan
Authors: Begum Sadaquat Mahpara , Sheikh Qurra‐tul‐ain Ali
Published: December 2010

Purpose

This paper is an attempt to analyze the study of low female work participation rate in Pakistan due to the religious, traditional, cultural values, the colonial ideology and the evolution of social institution that restrain women entry into the labour market.

Design/methodology/approach

In order to explore the objectives, the paper develops the classification of male and female age groups into three main categories, and analyze with the help of descriptive and mean methodology.

Findings

The findings of this paper show that the women are suffering from market discrimination and hence are pushed to separate low‐paid and low‐status jobs. Majority of women are employed in the unorganized sectors. Mostly, women are concentrated in sector known for low level of productivity, less income stability and low security of employment due to their dual role at home and workplace. Organized services sector is mostly government services, and provides employment to a small proportion of women. The rate of unemployment among women is consistently higher than that of men, both in rural and urban areas.

Research limitations/implications

The statistics are reflective of two hard‐core realities. The first factor is that women with no education or with some basic education are allowed to work due to intensive poverty and high rate of inflation; and the second factor is that the existing socio‐cultural norms continues to strengthen gender discrimination and are a source of a massive wastage of the human capital available in the country.

Practical implications

An analysis of structure of women employment reveals some qualitative improvement in the employment, due to high literacy rate and educational levels.

Social implications

Increasing levels of female labour force participation rate is a poverty‐induced phenomenon; a larger part is to be traced by improvement in literacy and education levels of women. There is some qualitative improvement in the employment, as women's share in secure and better paid jobs in the organized sector appears to be higher. With the increase in educational levels of women, faster growth of women's employment is observed in modern sectors and white‐collar jobs. Government machinery, non‐governmental organizations and progressive political parties should focus on the education of women if they want to enhance the status of women in Pakistan by implementing special schemes and programmes for absorbing them into different occupations, particularly in organized sector so as to improve their structures of employment as well as status of jobs.

Originality/value

Classification of male and female age groups is done into three main categories, i.e. age ten to 14, 25‐29 and 55‐59 for young, adult and old groups, respectively. This paper provides the clear picture of women problems and causes.
A socio‐economic view on management control
Authors: Verstegen Bernard H.J.
Published: December 2010

Purpose

The purpose of this paper is to introduce a framework of management control that accommodates phenomena found in literature, like the importance of social factors for coordinating behavior, rule‐following behavior and the evolutionary nature of control. Phenomena that the dominant economic view, based on self‐interested actors and financial incentives, cannot easily absorb.

Design/methodology/approach

The framework characterizes control as the coordination of behavior in organizations. It is based on two‐stage rationality in which rule‐following behavior gives meaning to self‐interest, and in doing so, coordinates behavior.

Findings

Management control of two‐stage rational behavior involves managing the various elements of the framework in combination. The evolution of the coordinating rules in an organization will be partly autonomous and partly formed within the organization. Therefore, management control entails influencing the development path of the organization. Although it is concerned with the formation of controls in an organization, it is not exclusively concerned with the design of controls.

Practical implications

The framework provides broader opportunities for managing an organization than the theory based on simple rational choice.

Social implications

In this socio‐economic approach, management will not consider controlling the “economic man” to be its core activity; instead, management will be coordinating the behavior of authentic human beings.

Originality/value

These aspects of management remain undervalued in mainstream literature on management control. The non‐mainstream literature does pay attention to these aspects; however, they are seldom integrated in one theoretical structure that is based explicitly on a broad conception of human behavior. The socio‐economic view can offer valuable insight into management and organization.
Counter hegemony, newspapers and the origins of anti‐colonialism in French India
Authors: Chapman Jane
Published: December 2010

Purpose

The purpose of this paper is to reveal the contribution of counter‐hegemonic communications towards the origins of anti‐colonialism in French India during the years 1935‐1937 and thereby to illuminate the relationship between press, economics and ideology in a colonial context.

Design/methodology/approach

The paper presents a qualitative study of local archives in Tamil and French, including indigenous print communications such as the workers' paperSwandanthiram. These are used as a prism for analysis of the development of a workers' public voice during major textile strikes, and assessed in the light of John Downing's definitions of advocacy journalism.

Findings

Communications were directly connected to disempowerment and lack of civil, political and economic rights. The formation of legal worker organisations for the first time and a new political party provided the context in which activist leaders adopted a twofold vertical and lateral strategy in their publications, to promote their formative anti‐colonial ideas.

Research limitations/implications

This research illuminates the relationship between press, economics and ideology in a colonial context, demonstrating the importance of economic factors in rise of nationalist movements and the way press usage is connected to basic civil, political and economic rights.

Originality/value

The paper traces a forgotten episode in the history of a neglected corner of French empire, significant for the emergence of the indigenous population – including peasant women – for the first time from the private to the public sphere as an organised force – a factor that has previously been ignored by historians.
Technology and economic fluctuations in the US food sector (1958‐2006)
Authors: Papageorgiou Theofanis , Michaelides Panayotis G. , Milios John G.
Published: December 2010

Purpose

The purpose of this paper is to deal with questions of instability and economic crises, deriving theoretical arguments from Marx's and Schumpeter's works and presenting relevant empirical evidence for the case of the US food manufacturing sector.

Design/methodology/approach

The paper attempts to interpret the economic fluctuations in the US food sector and find causal relationships between the crucial variables dictated by Schumpeterian and Marxian theory, such as technological change, output and profitability. In this context, a number of relevant techniques have been used, such as de‐trending, cointegration analysis, white noise tests, periodograms, cross‐correlations and Granger causality tests.

Findings

Most economic variables in the food manufacturing sector exhibit a similar pattern characterized by periodicities exhibiting a short‐term cycle, a mid‐term cycle and a long‐term cycle. Also, the economic variables investigated follow patterns which are consistent with the total economy. Furthermore, a relatively rapid transmission of technology in the economy takes place along with bidirectional causality between technology and output/profitability, which can be interpreted as indicating an ambivalent relationship in the flow of cause and effect. These findings give credit to certain aspects of the Schumpeterian and Marxist theories of economic crises, respectively.

Originality/value

This paper contributes to the literature in the following ways: first, it introduces a relevant methodological framework building on Schumpeterian and Marxist insights. Second, it uses several variables to study the economic fluctuations instead of delimiting its analysis, for instance, to industrial output. Third, the results are discussed in a broader political economy context, related to the US economy, as a whole.
Perceptions of healthcare practitioners in Saudi Arabia regarding their training in oral cancer prevention, and early detection
Authors: Jaber Louay , Shaban Sami , Hariri Deema , Smith Stephanus
Published: December 2010

Purpose

Healthcare practitioners (HCPs) have a major responsibility in the prevention and early detection of oral cancer (OC). Accordingly, adequate training in this area will positively enhance healthcare practitioners' accountability towards their patients. The present study was conducted in Saudi Arabia with the objective of assessing HCPs' opinion vis‐à‐vis OC prevention and early detection.

Design/methodology/approach

A cross‐sectional survey was distributed among HCPs in six different settings in Saudi Arabia.

Findings

Totals of 41.2 per cent and 63.4 per cent of HCPs thought that they are adequately trained to perform an OC examination and to palpate the lymph nodes, respectively. Similarly, 33.2 per cent and 25.8 per cent thought that they are adequately trained to provide tobacco and alcohol cessation education for their patients, respectively. Of HCPs, 45.1 per cent thought they had a low level of knowledge and training in OC prevention and the early detection thereof, 53.6 per cent agreed that their knowledge about OC was not current, and 82 per cent were comfortable with referring suspicious lesions to specialists.

Originality/value

It appears that the current knowledge and training in OC prevention and early detection among HCPs in Saudi Arabia is not up to the desired level. Accordingly, it is suggested that OC prevention and early detection should be given the necessary attention when establishing new continuous education strategies in Saudi Arabia.
Quality‐assuring intervention for technical medical staff at medical committees
Authors: Chaiter Yoram , Palma Elio , Machluf Yossy , Yona Avi , Cohen Avi , Pirogovsky Avinoam , Shohat Tamar , Ytzhak Amir , Ash Nachman
Published: December 2010

Purpose

This paper seeks to examine an intervention program which was developed in order to improve the performance and skills of technical medical personnel at the military recruitment medical committees.

Design/methodology/approach

Evaluation of the technician soldiers' performance was carried out by the usage of a specifically farmed survey, comprising a designed questionnaire, and direct observation of their work, including appraisal of their measurements and interpretation skills.

Findings

Prior to intervention, analysis revealed: insufficient knowledge of normal range of blood pressure and pulse values, visual acuity of color vision, urinalysis and their relation to the classification process at medical committees; and inadequate technicalities such as incorrect weight and height measurements.

Originality/value

The model of the intervention program could be modified and adopted by medical committees, sports medicine examinations, periodic screening procedures, and primary care medicine in order to improve the quality of medical records and medical care.
Quality of education at multidisciplinary case conferences in psychiatry
Authors: Naughton Marie , MacSuibhne Seamus , Callanan Ian , Guerandel Allys , Malone Kevin
Published: December 2010

Purpose – A large Dublin‐based teaching hospital facilitates a weekly Psychiatric Case Presentation meeting, which is relatively unique in medicine and even in psychiatry, in that there is a large variety of attendees from various multidisciplinary groups: consultant psychiatrists, psychiatric trainees, nurses, psychologists and psychoanalytic psychotherapists, occupational therapists, social workers and pastoral care staff. The aim of this audit is to assess the quality of education for members of different disciplines at these meetings, and to highlight the differing learning needs of the attendees. Design/methodology/approach – Group‐structured assessments and Likert scale questionnaires were used to identify what attendees thought were educational and what needed to be improved. Findings – Overall, the case conference is educationally worthwhile but there were several areas of dissatisfaction. Some felt that the case conference was overly medical in its orientation and that there was excessive medical jargon. The seating arrangements were not conducive to group discussion. Consultants and psychiatric trainees felt that the quality of the clinical presentations could be improved. Presentation skills teaching classes and topic‐based classes would be useful inclusions. Feedback to the multidisciplinary group on the patients' progress and feedback to the patient is important. Changes were implemented in areas of dissatisfaction, and these changes evaluated. Originality/value – The educational qualities of multidisciplinary Case Conferences need to be constantly evaluated to ensure that the learning needs of the different disciplines who attend are being met.
Do patients' perceptions exceed their expectations in private healthcare settings?
Authors: Mohd Suki Norazah , Chiam Chwee Lian Jennifer , Mohd Suki Norbayah
Published: December 2010

Purpose

The purpose of this paper is to investigate whether patients' perceptions exceed expectations when seeking treatment in private healthcare settings in the Klang Valley Region of Malaysia.

Design/methodology/approach

A survey was conducted among 191 patients in the Klang Valley Region of Malaysia to measure service quality of the private healthcare setting in Malaysia using SERVQUAL 5 dimensions model by Parasuraman et al. and three additional dimensions of the human element, when it comes to rendering good healthcare services, i.e. courtesy, communication and understanding of customers.

Findings

The results revealed that the customers' perceptions did not exceed their expectations, as they were dissatisfied with the level of healthcare services rendered by private healthcare settings in that they felt that the waiting time of more than an hour to receive the service was excessive and, when there was a problem, the healthcare provider did not provide a response fast enough.

Research limitations/implications

Only eight service quality dimensions were studied. The sample investigated is relatively small, where three private healthcare settings were selected.

Practical implications

It is recommended that hospital management should look into highlighted areas for which patients have high expectations.

Originality/value

The paper adds to the existing body of research on healthcare service quality, particularly on patients' perceptions and expectations. Survey results should be useful for continuous quality improvement.
Sustainable leadership in a Thai healthcare services provider
Authors: Kantabutra Sooksan
Published: December 2010

Purpose

Rhineland leadership practices contrast sharply with the prevailing Anglo/US business model of short‐term maximization of profitability, and are said to lead to greater corporate sustainability, at least in highly developed economies. However, the applicability of Rhineland leadership to less developed economies has not yet been demonstrated. This paper sets out to compare the business practices of a social enterprise that delivers healthcare services in Thailand and Avery's 19 sustainable leadership practices derived from Rhineland enterprises.

Design/methodology/approach

Adopting a case study approach, multi‐data collection methods included non‐participant observations made during visits to the enterprise, and reference to internal and published documentation and information. Semi‐structured interview sessions were held with many stakeholders, including top management, staff, patients and a former consultant.

Findings

In the Thai healthcare organization studied, evidence was found for compliance with 15 of Avery's 19 sustainable leadership elements, but to varying degrees. The elements were grouped into six core sets of practices: adopting a long‐term perspective, staff development, organizational culture, innovation, social responsibility, and ethical behavior. One element was found to be not applicable, and no evidence was found for conformity with Rhineland principles on the remaining three sustainable practices. The paper concludes that Avery's 19 Rhineland practices provide a useful framework for evaluating the corporate sustainability of this Thai enterprise.

Practical implications

Healthcare enterprises in Thailand and possibly in other Asian countries that wish to sustain their organizational success could adopt Avery's 19 Sustainable Leadership Grid elements to examine their leadership practices, and adjust them to become more sustainable.

Originality/value

The relevance of Rhineland sustainable leadership principles to enterprises in less developed economies remains to be investigated. This study attempts to uncover this unknown.
What is, could be better
Authors: Sandin‐Bojö Ann‐Kristin , Kvist Linda J. , Berg Marie , Wilde Larsson Bodil
Published: December 2010

Purpose

The aim of this study is to describe how Swedish women, planned for vaginal birth, perceive the quality of intrapartal care that they receive and the subjective importance they ascribe to their care.

Design/methodology/approach

The study was nested within a Swedish national survey of intrapartal care. The women whose care was investigated were invited to participate in the current study by the midwife who attended the birth. A total of 1,173 women agreed to answer a questionnaire about “quality of general care” and “quality of specific intrapartal care” at two months postpartum. The questions were posed in two ways, the perceived reality (PR) of care given and the subjective importance (SI) the women ascribed to this care.

Findings

A total of 739 women (63 percent) returned their questionnaires. Scores for PR and SI for “quality of general care“ were in the main high (PR range 2.98‐3.81; SI range 2.85‐3.85, out of a possible 4) and also for “quality of specific intrapartal care” (PR range 3.15‐3.86; SI range 3.23‐3.86, out of a possible 4). A total of 12 items showed statistically significantly higher scores for SI than for PR. Of the women, 81 percent agreed fully or mostly that the birth of their child was a positive experience.

Originality/value

The way in which women answer questions about intrapartal care reflects the way in which the questions are posed. This study therefore has asked not only how care was perceived but also what importance individual women ascribed to different areas of their care. The questionnaire used in this study allows identification of areas where “what is, could be better”.
Numerical simulation of sloshing motion inside a two dimensional rectangular tank by level set method
Authors: Wang Chung‐Yueh , Teng Jyh‐tong , Huang George P.G.
Published: December 2010

Purpose

The purpose of this paper is to develop the numerical simulated methodology for sloshing motion of fluid inside a two dimension rectangular tank, and parametric studies were performed for three parameters – excitation frequency, excitation amplitude, and liquid depth.

Design/methodology/approach

A numerically simulated methodology by using the cell‐centered pressure‐based SIMPLE scheme and level set method for the sloshing motion of fluid in a rectangular tank has been developed. The convection term in the Navier‐Stokes equations and the equations used in the level set method were treated by the second‐order upwind scheme. The temporal derivative terms were solved by the three‐level second order scheme. The diffusion term in the Navier‐Stokes equations alone was solved by the central‐difference scheme. All algebraic equations were solved by the point Gauss‐Seidel method. A fully implicit scheme to treat the level set distancing equation, written as the advection equation, was developed. In addition, the level set distancing equation was solved by the iterative procedure to determine the variation of free surface.

Findings

For given excitation amplitude together with a liquid depth, the free surface displacement increases when the excitation frequency is less than the resonance frequency of tank. However, the free surface displacement decreases when the excitation is greater than the resonant frequency of the tank. It is noted that the maximum free surface displacement is generated under the circumstance for which the excitation frequency approaches the resonant frequency. The excitation amplitude and the excitation frequency have a substantial effect on the impact pressure on the wall of the tank being investigated.

Originality/value

The sloshing motion of fluid in a rectangular tank has been studied by researchers and scholars using many numerical methods; however, literature employing the level set method to study the sloshing motion of fluid is limited. In this study, the cell‐centered pressure‐based SIMPLE scheme and level set method can be employed to predict the sloshing motion. The numerical methodology can help the engineer to predict sloshing motion of fluid.
Control of vortex shedding from a circular cylinder using imposed transverse magnetic field
Authors: Singha Sintu , Sinhamahapatra K.P.
Published: December 2010

Purpose

The purpose of this paper is to simulate the flow of a conducting fluid past a circular cylinder placed centrally in a channel subjected to an imposed transverse magnetic field to study the effect of a magnetic field on vortex shedding at different Reynolds numbers varying from 50 to 250.

Design/methodology/approach

The two‐dimensional incompressible laminar viscous flow equations are solved using a second‐order implicit unstructured collocated grid finite volume method.

Findings

An imposed transverse magnetic field markedly reduces the unsteady lift amplitude indicating a reduction in the strength of the shed vortices. It is observed that the periodic vortex shedding at the higher Reynolds numbers can be completely suppressed if a sufficiently strong magnetic field is imposed. The required magnetic field strength to suppress shedding increases with Reynolds number. The simulation shows that the separated zone behind the cylinder in a steady flow is reduced as the magnetic field strength is increased.

Originality/value

In this paper, due attention is given to resolve and study the unsteady cylinder wake and its interaction with the shear‐layer on the channel wall in the presence of a magnetic field. A critical value of the Hartmann number for complete suppression of the shedding at a given Reynolds number is found.
Numerical investigation of the influence of a hole imperfection on film cooling effectiveness
Authors: Nemdili Fadéla , Azzi Abbès , Jubran B.A.
Published: December 2010

Purpose

The purpose of this paper is to report a numerical investigation of jet‐cross‐flow interaction in the presence of imperfection inside the injection hole with application to film cooling of turbine blades.

Design/methodology/approach

The work includes the prediction of the thermal and hydrodynamic fields by solving the Reynolds Averaged Navier Stokes and energy equations using the finite volume method with a body‐fitted hexahedral unstructured grid. The turbulence field is resolved by use of the k‐epsilon turbulence model.

Findings

The computational results show a dramatic and rapid decrease of the film cooling effectiveness when the obstruction is superior to 50 per cent. It is found that when the obstruction is close to the exit hole, the thermal protection is significantly reduced.

Research limitations/implications

The present numerical investigation is simply directed towards a qualitative investigation of hole imperfection effects on film cooling.

Practical implications

The motivation comes from several industrial applications such as film cooling of gas turbine components and fuel injection. One of the main challenges of using film cooling is the blockage of holes by particles ingested by the engine during landing/take off or due to application of thermal barrier coating or due to combustion particles as well as inaccuracies that result from drilling of holes.

Originality/value

The main goal of the present study is to conduct a numerical parametric investigation rather than reproducing the exact Jovanović's experimentation.
MHD stagnation‐point flow towards a shrinking sheet
Authors: Lok Y.Y. , Ishak A. , Pop I.
Published: December 2010

Purpose

The purpose of this paper is to theoretically investigate the steady two‐dimensional magnetohydrodynamic (MHD) boundary layer flow over a shrinking sheet. The effects of stretching and shrinking parameter as well as magnetic field parameter near the stagnation point are studied.

Design/methodology/approach

A similarity transformation is used to reduce the governing partial differential equations to a set of nonlinear ordinary differential equations which are then solved numerically using Keller‐box method.

Findings

The solution is unique for stretching case; however, multiple (dual) solutions exist for small values of magnetic field parameter for shrinking case. The streamlines are non‐aligned and a reverse flow is formed near the surface due to shrinking effect.

Practical implications

The flow due to a stretching or shrinking sheet is relevant to several practical applications in the field of metallurgy, chemical engineering, etc. For example, in manufacturing industry, polymer sheets and filaments are manufactured by continuous extrusion of the polymer from a die to a windup roller, which is located at a finite distance away. In these cases, the properties of the final product depend to a great extent on the rate of cooling which is governed by the structure of the boundary layer near the stretching surface.

Originality/value

The present results are original and new for the MHD flow near the stagnation‐point on a shrinking sheet. For shrinking case, the velocity on the boundary is towards a fixed point which would cause a velocity away from the sheet. Therefore, this paper is important for scientists and engineers in order to become familiar with the flow behaviour and properties of such MHD flow and the way to predict the properties of this flow for the process equipments.
Design optimisation of a regenerative pump using numerical and experimental techniques
Authors: Quail Francis , Scanlon Thomas , Stickland Matthew
Published: December 2010

Purpose

Regenerative pumps are the subject of increased interest in industry as these pumps are low‐cost, low‐specific speed, compact and able to deliver high heads with stable performance characteristics. However, these pumps have a low efficiency (35‐50 per cent). The complex flow field within the pumps represents a considerable challenge to detailed mathematical modelling. Better understanding of the flow field would result in improvement of the pump efficiency. The purpose of this paper is to consider a numerical and experimental analysis of a regenerative pump to simulate the flow field and math pump performance.

Design/methodology/approach

This paper outlines the use of a commercial computational fluid dynamics (CFD) code to simulate the flow field within the regenerative pump and compare the CFD results with new experimental data. A novel rapid manufacturing process is used to consider the effect of impeller geometry changes on the pump efficiency.

Findings

The CFD results demonstrate that it is possible to represent the helical flow field for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests.

Research limitations/implications

The design optimisation only considers a number of blade geometry changes. The future work will consider a much broader spectrum of design modifications which have resulted in efficiency improvements in the past.

Practical implications

The ability to use CFD modelling in conjunction with rapid manufacturing techniques has meant that more complex geometry configurations can now be assessed with better understanding of the flow field effects and resulting efficiency.

Originality/value

This paper presents new flow field visualisation and better correlation to the matched performance than the current limited mathematical models. This paper also presents a novel method for rapid manufacturing of the pump impeller.
Numerical simulations of natural convection heat transfer along a vertical cylinder
Authors: Rafique Muhammad , Ahmad I. , Abdul Basit M. , Begum Romana , Aziz Wajid , Farooq Muhammad , Rasheed Qureshi Kamran
Published: December 2010

Purpose

The purpose of this paper is to present a numerical solution for the problem of steady laminar flow and heat transfer characteristics of viscous incompressible fluid.

Design/methodology/approach

For this purpose a two dimensional code has been developed to simulate the natural convection heat transfer along a vertical cylinder, for four different geometries: from vertical cylinder in infinite medium; from a vertical flat plate in an infinite medium; from an open assembly of a finite vertical cylinder; and from an open rectangular pitch assembly of cylinders.

Findings

The effects of various parameters of interest have been discussed through simulations. The Nusselt numbers of constant wall temperature and constant heat flux cylinders calculated numerically and compared with Lee et al. and Heckel et al., respectively, and are found within reasonable agreement. For large radius, a vertical cylinder has been treated as a vertical flat plate, so that the curvature effects become negligible. For the case of vertical flat plate, Nusselt number has been compared with analytical relation for the local Nusselt number given by Jaluria.

Practical implications

The natural convection has been studied for four different geometries: the flow regime in all the case studies has been assumed to be Laminar.

Originality/value

Computer code developed for current study can be applied to many other geometries to simulate natural convection heat transfer.
Reuse of waste water from ready‐mixed concrete plants
Authors: Tsimas Stamatis , Zervaki Monika
Published: December 2010

Purpose

The purpose of this study is the examination of the properties of waste water obtained from a ready‐mixed concrete plant and its utilization potential as mixing water for concrete production.

Design/methodology/approach

Samples of waste water from several points of a water recycling process from a ready‐mixed concrete plant were examined for their chemical properties (Cl‐, SO42‐, alkalies, total solids, pH) and compared with the specifications applied for concrete mixing water. Also samples of dry sludge powder from the water‐recycling process tank were taken and tested for their chemical composition, particle size distribution, mineralogical composition and thermogravimetrical results. The water samples were examined for their behavior in concrete specimens with and without admixtures and also for their effect in water demand and setting times in cement pastes.

Findings

All tests showed that waste water is suitable for concrete mixing water and that it can be used without any treatment or dilution, thus contributing to water saving.

Practical implications

Waste water from ready‐mixed concrete plants is classified as waste hazardous for disposal due to its high pH value (over 11.5). Very few ready‐mixed concrete plants that recycle waste water follow a complicated process through multiple overflows and a stage of neutralization, with HClaq addition.

Originality/value

It is obvious that the results of this investigation contribute to the protection of the environment from hazardous waste water disposal and the ready‐mixed concrete industry from fresh water costs and any additional cost for buying and conserving an unnecessarily complicated water‐recycling system.
Prospects for CO2 capture in European industry
Authors: Rootzén Johan , Kjärstad Jan , Johnsson Filip
Published: December 2010

Purpose

The aim of this study is to assess the role of CO2 capture and storage (CCS) technologies in the reduction of CO2 emissions from European industries.

Design/methodology/approach

A database covering all industrial installations included in the EU ETS has been created. Potential capture sources have been identified and the potential for CO2 capture has been estimated based on branch‐ and plant‐specific conditions. Emphasis is placed here on three branches of industry with promising prospects for CCS: mineral oil refineries, iron and steel, and cement manufacturers.

Findings

A relatively small number (∼270) of large installations (>500,000 tCO2/year) dominates emissions from the three branches investigated in this study. Together these installations emit 432 MtCO2/year, 8 percent of EU's total greenhouse gas emissions. If the full potential of emerging CO2 capture technologies was realized, some 270‐330 MtCO2 emissions could be avoided annually. Further, several regions have been singled out as particularly suitable to facilitate integrated CO2 transport networks. The most promising prospects for an early deployment of CCS are found in the regions bordering the North Sea.

Research limitations/implications

Replacement/retrofitting of the existing plant stock will involve large investments and deployment will take time. It is thus important to consider how the current industry structure influences the potential to reduce CO2 in the short‐ medium and long term. It is concluded that the age structure of the existing industry plant stock and its implications for the timing and deployment rate of CO2 capture and other mitigation measures are important and should therefore be further investigated.

Practical implications

CCS has been recognized as a key option for reducing CO2 emissions within the EU. This assessment shows that considerable emission reductions could be achieved by targeting large point sources in some of the most emission‐intensive industries. Yet, a number of challenges need to be resolved in all parts of the CCS chain. Efforts need to be intensified from all stakeholders to gain more experience with the technological, economical and social aspects of CCS.

Originality/value

This study provides a first estimate of the potential role for CO2 capture technologies in lowering CO2 emissions from European heavy industry. By considering wider system aspects as well as plant‐specific conditions the assessment made in this study gives a realistic overview of the prospects and practical limitations of CCS in EU industry.