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1 – 10 of over 25000Ashwini Kumar Nayak, Kanungo Barada Mohanty, Vinaya Sagar Kommukuri and Kishor Thakre
The purpose of this paper is to show the effect of randomness of wind speed on the capacity value estimation of wind power. Three methods that incorporate hourly wind speed have…
Abstract
Purpose
The purpose of this paper is to show the effect of randomness of wind speed on the capacity value estimation of wind power. Three methods that incorporate hourly wind speed have been evaluated.
Design/methodology/approach
Wind speed is simulated using autoregressive moving average method and is included in the calculation of reliability index as a negative load on an hourly basis. The reliability index is calculated before and after the addition of wind capacity. Increment of load or alteration of conventional capacity will lead to capacity estimation.
Findings
Among the aforementioned three methods, the former two exclude the availability rate and give the exact value for wind capacity addition. The third method is based on the availability rate and provides a little higher capacity value, indicating a clear correlation between availability and capacity value.
Originality/value
The methods that exclude the availability rate show consistent results. By including the availability rate, the third method predicts the inverse relation between the availability rate and the capacity value.
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How large should a distribution facility be initially? What size additions to the facility should be planned and when? For example, should a regional distribution centre be built…
Abstract
How large should a distribution facility be initially? What size additions to the facility should be planned and when? For example, should a regional distribution centre be built to accommodate the projected inventory volume at the time of its completion or the projected volume some five, ten or fifteen years in the future? Should investments in the building and the materials handling system coincide or be planned separately? Finally, can planned expansions be economically postponed by temporarily leasing outside space or by temporarily expanding the work force to achieve above‐capacity utilisation of the existing facility?
A striking feature of Jaques' work is his “no nonsense” attitude to the “manager‐subordinate” relationship. His blunt account of the origins of this relationship seems at first…
Abstract
A striking feature of Jaques' work is his “no nonsense” attitude to the “manager‐subordinate” relationship. His blunt account of the origins of this relationship seems at first sight to place him in the legalistic “principles of management” camp rather than in the ranks of the subtler “people centred” schools. We shall see before long how misleading such first impressions can be, for Jaques is not making simplistic assumptions about the human psyche. But he certainly sees no point in agonising over the mechanism of association which brings organisations and work‐groups into being when the facts of life are perfectly straightforward and there is no need to be squeamish about them.
Jiwan S. Sidhu, Tasleem Zafar, Abdulwahab Almusallam, Muslim Ali and Amani Al-Othman
The major objective of this research work was to evaluate various physico-chemical characteristics, such as, chemical composition, antioxidant capacity, objective color and…
Abstract
Purpose
The major objective of this research work was to evaluate various physico-chemical characteristics, such as, chemical composition, antioxidant capacity, objective color and texture profile analysis (TPA) of the wheat flour/chickpea flour (CF) blends, so that nutritious baked products could be consumed by the type-2 diabetic persons.
Design/methodology/approach
Wholegrain wheat flour (WGF) and white wheat flour (WWF) were substituted with CF at 0 to 40% levels. These wheat flour/CF blends were analyzed for proximate composition, the prepared dough and baked breads were tested for objective color, antioxidant capacity as trolox equivalent antioxidant capacity (TEAC), malondialdehyde (MDA) and total phenolic content (TPC) and TPA.
Findings
WGF had the highest TEAC (117.42 mM/100g) value, followed by WWF (73.98 mM/100g) and CF (60.67 mM/100g). TEAC, MDA and TPC values varied significantly among all the three flour samples.
Research limitations/implications
Inclusion of whole chickpea (without dehulling) flour in such type of blends would be another interesting investigation during the future research studies.
Practical implications
These research findings have a great potential for the production of these baked products for human consumption on an industrial scale.
Social implications
Production of breads using wheat flour and CF blends would benefits the consumers.
Originality/value
Production of Arabic and pan breads using wheat flour and CF blends would, therefore, combine the benefits of both the needed proteins of plant origin and the health-promoting bioactive compounds, in a most sustainable way for the consumers.
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The paper describes various options which enhance the durability of reinforced concrete by reducing the risk of reinforcement corrosion. These include different cementing systems…
Abstract
The paper describes various options which enhance the durability of reinforced concrete by reducing the risk of reinforcement corrosion. These include different cementing systems, chemical admixtures and fibres, and surface treatments and coatings. Models for predicting the time to corrosion are described and the ways in which the different measures influence the critical input parameters are discussed. Durability design is also discussed, the limitations of the current deemed‐to‐satisfy approach are highlighted, and a new performance based method is proposed. Finally, a methodology is proposed for selecting the most cost‐effective options in relation to the required design life of the structure.
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U. Gianfranco Spizzirri, Paolino Caputo, Rosa Nicoletti, Pasquale Crupi, Fabrizio D'Ascenzo, Cesare Oliverio Rossi, Maria Lisa Clodoveo, Francesca Aiello and Donatella Restuccia
This study aims to investigate unripe carob pod as a source of antioxidant molecules useful in the eco-friendly synthesis of a gelatin conjugate. This one was involved in the…
Abstract
Purpose
This study aims to investigate unripe carob pod as a source of antioxidant molecules useful in the eco-friendly synthesis of a gelatin conjugate. This one was involved in the preparation of gummies able to produce remarkable human health benefits.
Design/methodology/approach
Eco-friendly strategies (ultrasound-assisted extraction, low temperatures and eco-friendly solvents) were employed in the extraction of active molecules. Antioxidant molecules were involved in the grafting reaction with gelatin chains (ascorbic acid/hydrogen peroxide couple as initiator system). Gelatin conjugate represents a useful material able to prepare gummies with remarkable rheological and antioxidant performances over time.
Findings
Experimental results confirmed that the green approach allowed the achievement of extracts with remarkable antioxidant properties due to the presence of phenolic moieties. Gelatin conjugate synthesis preserved these functionalities, usefully exploited in the preparation of gummies with significant structural and biological features.
Originality/value
Compared to the literature data the preparation of the gummies with outstanding biological properties was performed by employing functional gelatin synthesized by an eco-friendly approach.
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Lingcheng Kong, Zhong Li, Ling Liang and Jiaping Xie
When the power generator faces uncertain and independent electricity spot price and renewable energy source supply, two different conditions need to be considered: the…
Abstract
Purpose
When the power generator faces uncertain and independent electricity spot price and renewable energy source supply, two different conditions need to be considered: the distributions of renewable energy source electricity and electricity spot price are independent or dependent. The purpose of this paper is to explore the capacity investment strategy under volatile electricity spot price when renewable energy penetration rate is low, taking into account these two conditions.
Design/methodology/approach
The authors design a capacity investment model under dual uncertainties and consider how to optimize the investment capacity in order to maximize profit under two different conditions.
Findings
The authors find that when renewable energy supply fluctuation is unrelated to spot electricity price fluctuation, the renewable energy power profitability is determined by the average cost of spot electricity price and equivalent cost. When renewable energy supply fluctuation is related to spot electricity price fluctuation, the renewable energy power profitability is determined by the market value and the construction and maintenance cost.
Practical implications
Faced with the conflict of the renewable energy supply, the authors need to understand how to plan the generation capacity with intermittent renewable sources. The result helps renewable energy become competitive in the electricity market under loose regulations.
Originality/value
The authors compare two capacity investment strategies that the renewable energy supply fluctuation is related and unrelated to spot electricity price.
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Guizhi Lyu, Peng Wang, Guohong Li, Feng Lu and Shenglong Dai
The purpose of this paper is to present a wall-climbing robot platform for heavy-load with negative pressure adsorption, which could be equipped with a six-degree of freedom (DOF…
Abstract
Purpose
The purpose of this paper is to present a wall-climbing robot platform for heavy-load with negative pressure adsorption, which could be equipped with a six-degree of freedom (DOF) collaborative robot (Cobot) and detection device for inspecting the overwater part of concrete bridge towers/piers for large bridges.
Design/methodology/approach
By analyzing the shortcomings of existing wall-climbing robots in detecting concrete structures, a wall-climbing mobile manipulator (WCMM), which could be compatible with various detection devices, is proposed for detecting the concrete towers/piers of the Hong Kong-Zhuhai-Macao Bridge. The factors affecting the load capacity are obtained by analyzing the antislip and antioverturning conditions of the wall-climbing robot platform on the wall surface. Design strategies for each part of the structure of the wall-climbing robot are provided based on the influencing factors. By deriving the equivalent adsorption force equation, analyzed the influencing factors of equivalent adsorption force and provided schemes that could enhance the load capacity of the wall-climbing robot.
Findings
The adsorption test verifies the maximum negative pressure that the fan module could provide to the adsorption chamber. The load capacity test verifies it is feasible to achieve the expected bearing requirements of the wall-climbing robot. The motion tests prove that the developed climbing robot vehicle could move freely on the surface of the concrete structure after being equipped with a six-DOF Cobot.
Practical implications
The development of the heavy-load wall-climbing robot enables the Cobot to be installed and equipped on the wall-climbing robot, forming the WCMM, making them compatible with carrying various devices and expanding the application of the wall-climbing robot.
Originality/value
A heavy-load wall-climbing robot using negative pressure adsorption has been developed. The wall-climbing robot platform could carry a six-DOF Cobot, making it compatible with various detection devices for the inspection of concrete structures of large bridges. The WCMM could be expanded to detect the concretes with similar structures. The research and development process of the heavy-load wall-climbing robot could inspire the design of other negative-pressure wall-climbing robots.
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JiaRong Wang, Bo He and XiaoQiang Chen
This paper aims to obtain a symmetrical step-down topology with lower equivalent capacity and wider step-down range under the condition of the same output. Two new symmetrical…
Abstract
Purpose
This paper aims to obtain a symmetrical step-down topology with lower equivalent capacity and wider step-down range under the condition of the same output. Two new symmetrical step-down topologies of star-connected autotransformers are proposed in this paper. Taking the equivalent capacity as the main parameter, the obtained topologies are modeled and analyzed in detail.
Design/methodology/approach
This paper adopts the research methods of design, modeling, analysis and simulation verification. First, the star-connected autotransformer is redesigned according to the design objective of symmetrical step-down topology. In addition, the mathematical model of two topologies is established and a detailed theoretical analysis is carried out. Finally, the theoretical results are verified by simulation.
Findings
Two symmetrical star-connected autotransformer step-down topologies are designed, the winding configurations of the corresponding topology are presented, the step-down ranges of these three topologies are calculated and the influence of step-down ratio on the equivalent capacity of autotransformer are analyzed. Through analysis, the target step-down topologies are obtained when the step-down ratio is [1.1, 5.4] and [1.1, 1.9] respectively.
Research limitations/implications
Because the selected research object is only a star-connected autotransformer, the research results may lack generality. Therefore, researchers are encouraged to further study the topologies of other autotransformers.
Practical implications
This paper includes the implications of the step-down ratio on the equivalent capacity of autotransformers and the configuration of transformer windings.
Originality/value
The topologies designed in this paper enable star-connected autotransformer in the 12-pulse rectifier to be applied in step-down circumstances rather than situations of harmonic reduction only. At the same time, this paper provides a way that can be used to redesign the autotransformer in other multi-pulse rectifier systems, so that those transformers can be used in voltage regulation.
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Peixin Liang, Yulong Pei, Feng Chai and Shukang Cheng
For high torque-density permanent magnet synchronous in-wheel motor, service life and electromagnetic performance are related directly to winding temperature. The purpose of this…
Abstract
Purpose
For high torque-density permanent magnet synchronous in-wheel motor, service life and electromagnetic performance are related directly to winding temperature. The purpose of this paper is to investigate the equivalent stator slot model to calculate the temperature of winding accurately.
Design/methodology/approach
This paper analyzes the the law of heat flux transfer in slot, which points the main influence factors of equivalent stator slot model. Thermal network model is used to investigate the drawbacks of conventional equivalent model. Based on the law of heat transfer in stator slot, a new layered winding model is put forward. According to winding type and property of impregnations, detailed method and equivalent principle of the new model are presented. The accuracy of this new method has been verified experimentally.
Findings
An accurate equivalent stator slot model should be built according to the low of heat transfer. According to theory analysis, the drawbacks of conventional equivalent stator slot model are pointed: it cannot reflect the temperature gradient of winding; the maximum and the average temperature of winding are much higher than actual value. For the new layered model, equivalent principle is related to winding type and property of impregnations, which makes the new model widely used.
Originality/value
This paper presents a new layered model, and shows detailed method, which is more meaningful for designers. The new layered model takes winding type and property of impregnations into account, which makes the new model widely used. It is verified experimentally that layered model is applicable to not only steady-state temperature field but also transient temperature field.
Details