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This study aims to investigate the effect of process parameters of blow room machines on openness degree and quality of cotton tufts in a blow room.
Abstract
Purpose
This study aims to investigate the effect of process parameters of blow room machines on openness degree and quality of cotton tufts in a blow room.
Design/methodology/approach
For this purpose, an experimental Box–Behnken design (BBD) was used, and the process parameters were the angles of the grid bars underneath the opening rollers of CVT3 beaters and the distance between feed roller of the first opening roller of CVT3.
Findings
It was found that the cotton tuft openness increased by increasing the angles of grid bars and by decreasing the distance between the feed roller and first opening roller on CVT3 beater. Further, the optimization procedure showed that an optimum value of cotton tuft openness (in laser method) was determined for specific levels of the process parameters.
Originality/value
The originality of this investigation is that it showed the individual effects and interactions of the most important factors in two tufting machines instead of only one machine. This study is important because it helps cotton yarn spinners to improve the quality of the final yarns by optimizing the levels of tuft openness which in turn improves fiber cleaning.
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Stephan Klomberg, Ernst Farnleitner, Gebhard Kastner and Oszkár Bíró
The purpose of this paper is to present a new computational fluid dynamics model for large electrical machines to simulate the heat transfer at specific components to the…
Abstract
Purpose
The purpose of this paper is to present a new computational fluid dynamics model for large electrical machines to simulate the heat transfer at specific components to the appropriate ventilation method. The most damageable parts for overheating in generators are the end winding bars, pole windings and stator ducts.
Design/methodology/approach
The reduced model introduced is basically derived from the state-of-the-art pole section model (PSM) and enables faster computations for heat transfer and cooling simulations of electrical machines. The fundamentals of the two methods and the grid generation are described. Two PSMs and four different reduced models are presented and compared among each other to tune the reduced model.
Findings
As a topic of outstanding interest in large hydro generators, the heat transfer at the end winding bars is solved with the aid of the reduced model. This slot sector model (SSM) has been validated and the computation time has been reduced enormously in comparison to the state-of-the-art PSM.
Research limitations/implications
The heat transfer has been carried out only for the end winding region of large hydro generators. The effect of the reduced model on the pole sections and stator ducts has not been investigated. Nevertheless, the reduced model is also valid for large motors.
Practical implications
This reduced model can finally be used for parametric studies with different cooling schemes and boundary conditions in the design process.
Originality/value
The comparison of various SSMs to PSMs shows an acceptable accuracy of the reduced model in combination with a rather low computation time. Due to modeling one slot only, the MFR-MP approach is an adequate and fast analyzing method for this kind of model structure.
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Mehdi Jahangiri, Ahmad Haghani, Shahram Heidarian, Ali Mostafaeipour, Heidar Ali Raiesi and Akbar Alidadi Shamsabadi
Rural areas are one of the effective regions in economy and self-sufficiency field especially in agricultural and livestock section. Planning in the rural section and the effort…
Abstract
Purpose
Rural areas are one of the effective regions in economy and self-sufficiency field especially in agricultural and livestock section. Planning in the rural section and the effort in solving the problems of farmers lead to increase their interest in farming and manufacturing in the villages and decrease their migration to the cities and metropolitans. Therefore, the present study aimed at feasibility of electricity to a rural household in Iran using off-grid solar-based hybrid system.
Design/methodology/approach
In renewable energy projects, a successful evaluation requires suitable criteria so that one can properly analyze the operational behavior of all feasible scenarios. In the present paper, HOMER software has been used for this purpose for a village with no access to electricity grid (Bar Aftab-e Jalaleh, Iran). Due to drastic fluctuation of fossil fuel prices and varied solar radiations in various years because of climate change, sensitivity analysis has been performed using HOMER.
Findings
In the optimum status economically, 70% of needed energy is provided by solar cells at the price 0.792 $/kWh. The comparison between the optimum condition economically and the condition that only use fossil fuels revealed that the return on investment will occur after less than 2 years and have remained profitable over 23 years.
Social implications
The authors hope that the results of this study can be used in planning of the authorities to realize the interests of people in this village.
Originality/value
According to the surveys, despite Iran being the first country in terms of providing solar power to the villages, so far no socio-economic-environmental assessment has been done for a solar cell-based micro-grid in an off-grid mode for a remote village that is deprived of electricity from a national electricity grid. In addition, for the first time in Iran, the effect of the fuel price and solar radiation parameters variability on the performance of system have been investigated.
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Fenella Henderson, Neil Anderson and Steve Rick
Describes a three‐phase study to validate and redesign the graduateassessment centres used by ICL. Analyses results by multimethodmultitrait correlation matrix and…
Abstract
Describes a three‐phase study to validate and redesign the graduate assessment centres used by ICL. Analyses results by multimethod multitrait correlation matrix and intercorrelating ratings of dimensions both across and within exercises. Factor analyses correlation matrices by the principal components method. Evaluates differences between the hired and rejected groups by discriminant function analysis. Assesses the predictive validity by multiple regression analysis on the performance ratings and salary information. Discusses the redesign of the recruitment procedure to select for future competences as well as present day requirements.
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Ali Kaveh and Ataollah Zaerreza
This paper aims to present a new multi-community meta-heuristic optimization algorithm, which is called shuffled shepherd optimization algorithm (SSOA). In this algorithm.
Abstract
Purpose
This paper aims to present a new multi-community meta-heuristic optimization algorithm, which is called shuffled shepherd optimization algorithm (SSOA). In this algorithm.
Design/methodology/approach
The agents are first separated into multi-communities and the optimization process is then performed mimicking the behavior of a shepherd in nature operating on each community.
Findings
A new multi-community meta-heuristic optimization algorithm called a shuffled shepherd optimization algorithm is developed in this paper and applied to some attractive examples.
Originality/value
A new metaheuristic is presented and tested with some classic benchmark problems and some attractive structures are optimized.
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E. Livya and S. Nadaraja Pillai
This paper aims to study the extended trailing edge airfoil for a range of angle of attack at different intensities of turbulence.
Abstract
Purpose
This paper aims to study the extended trailing edge airfoil for a range of angle of attack at different intensities of turbulence.
Design/methodology/approach
In this paper, an experimental study on NACA 0020 airfoil with thin extended trailing edge modification of amplitude of h = 0.1c, 0.2c and 0.3c at the Reynolds number of 2.14 × 105 are tested. The research was carried out for an angle of attack ranging from 0° = α = 35° for the turbulence intensity of 0.3%, 3%, 5%, 7% and 12%. From the experimental readings, the surface pressures are scanned using a Scanivalve (MPS2464) pressure scanner for a sampling frequency of 700 Hz. The scanned pressures are converted to aerodynamic force coefficient and the results are combined and discussed.
Findings
The airfoil with the extended trailing edge will convert the adverse pressure gradient to a plateau pressure zone, indicating the delayed flow separation. The CL value at higher turbulence intensity (TI = 12%) for the extended trailing edge over perform the base airfoil at the post-stall region. The maintenance of flow stability is observed from the spectral graph.
Practical implications
A thin elongated trailing edge attached to the conventional airfoil serves as a flow control device by delaying the stall and improving the lift characteristics. Additionally, extending the airfoil's trailing edge helps to manage the performance of the airfoil even at a high level of turbulence.
Originality/value
Distinct from existing studies, the presented results reveals how the extended trailing edge attached to the airfoil performs in the turbulence zone ranging from 0.3% to 12% of TI. The displayed pressure distribution explains the need for increasing trailing edge amplitude (h) and its impact on flow behaviour. The observation is that extended trailing edge airfoil bears to maintain the performance even at higher turbulence region.
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Jun Xiu Low, Poi Ngian Shek and Mahmood Md Tahir
Composite slabs are gaining wide acceptance in many countries as they lend themselves to faster, lighter and more economic in construction buildings. The strength of composite…
Abstract
Composite slabs are gaining wide acceptance in many countries as they lend themselves to faster, lighter and more economic in construction buildings. The strength of composite slabs system relies on the bonding action between the concrete and the steel deck, the shear connections and the cross-sectional resistance of steel beam. However, structural behaviour of composite slab is a complex phenomenon and therefore experimental study is often conducted to establish the actual strength of the structure under ultimate load capacity. The main objective of this study is to determine the structural behaviour of composite slab system until ultimate limit state. Total of two specimens are examined in order to obtain failure mechanism of the composite structure under full load capacity. A new design approach of composite slab for roofing system are proposed in this study to construct a composite slab system that can float in the water but not wash away by flood. The lightweight materials in this composite construction are cold-formed steel and foam concrete. The system focuses on the concept of Industrialised building system (IBS) to reduce the cost and construction time.
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The aim of the present study is to add to the existing research on online city branding by studying how metropolitan cities are internationally positioned using the internet and…
Abstract
Purpose
The aim of the present study is to add to the existing research on online city branding by studying how metropolitan cities are internationally positioned using the internet and online branding. The focus is on objectives and strategies, method and expression (including five illustrations), and challenges in online city branding.
Design/methodology/approach
The article relies on a single-case study approach, using the Chinese city of Chengdu as a case and illustration. Methods used are interviews, observations and documentation (including online material).
Findings
The study illustrates how Chengdu uses online city branding in its international positioning. Chengdu's online branding is influenced by certain imagery, as well as challenges. Collaboration and endorsement crystalize as central elements in Chengdu's online city branding.
Research limitations/implications
This article and study can be seen as an important element in broadening the understanding for online city branding to international audiences.
Practical implications
The study offers insights to practitioners on how online city branding is carried out in a Chinese context and in the city of Chengdu.
Originality/value
The study can be regarded as an important contribution to an area of practice and research which still is fairly new and unexplored, and an area that hitherto has not been well covered in the international literature.
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