Search results for: mechanical behaviour
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5294

Search results for: mechanical behaviour

5204 The Overload Behaviour of Reinforced Concrete Flexural Members

Authors: Angelo Thurairajah

Abstract:

Sufficient ultimate deformation is necessary to demonstrate the member ductility, which is dependent on the section and the material ductility. The concrete cracking phase of softening prior to the plastic hinge formation is an essential feature as well. The nature of the overload behaviour is studied using the order of the ultimate deflection. The ultimate deflection is primarily dependent on the slenderness (span to depth ratio), the ductility of the reinforcing steel, the degree of moment redistribution, the type of loading, and the support conditions. The ultimate deflection and the degree of moment redistribution from the analytical study are in good agreement with the experimental results and the moment redistribution provisions of the Australian Standards AS3600 Concrete Structures Code.

Keywords: ductility, softening, ultimate deflection, overload behaviour, moment redistribution

Procedia PDF Downloads 52
5203 Engineering Microstructural Evolution during Arc Wire Directed Energy Deposition of Magnesium Alloy (AZ31)

Authors: Nivatha Elangovan, Lakshman Neelakantan, Murugaiyan Amirthalingam

Abstract:

Magnesium and its alloys are widely used for various lightweight engineering and biomedical applications as they render high strength to low weight ratio and excellent corrosion resistance. These alloys possess good bio-compatibility and similar mechanical properties to natural bone. However, manufacturing magnesium alloy components by conventional formative and subtractive methods is challenging due to their poor castability, oxidation potential, and machinability. Therefore, efforts are made to produce complex-design containing magnesium alloy components by additive manufacturing (AM). Arc-wire directed energy deposition (AW-DED), also known as wire arc additive manufacturing (WAAM), is more attractive to produce large volume components with increased productivity than any other AM technique. In this research work, efforts were made to optimise the deposition parameters to build thick-walled (about 10 mm) AZ31 magnesium alloy components by a gas metal arc (GMA) based AW-DED process. By using controlled dip short-circuiting metal transfer in a GMA process, depositions were carried out without defects and spatter formation. Current and voltage waveforms were suitably modified to achieve stable metal transfer. Moreover, the droplet transfer behaviour was analysed using high-speed image analysis and correlated with arc energy. Optical and scanning electron microscopy analyses were carried out to correlate the influence of deposition parameters with the microstructural evolution during deposition. The investigation reveals that by carefully controlling the current-voltage waveform and droplet transfer behaviour, it is possible to stabilise equiaxed grain microstructures in the deposited AZ31 components. The printed component exhibited an improved mechanical property as equiaxed grains improve the ductility and enhance the toughness. The equiaxed grains in the component improved the corrosion-resistant behaviour of other conventionally manufactured components.

Keywords: arc wire directed energy deposition, AZ31 magnesium alloy, equiaxed grain, corrosion

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5202 Effect of Infill Density and Pattern on the Compressive Strength of Parts Produced by Polylactic Acid Filament Using Fused Deposition Modelling

Authors: G. K. Awari, Vishwajeet V. Ambade, S. W. Rajurkar

Abstract:

The field of additive manufacturing is growing, and discoveries are being made. 3D printing machines are also being developed to accommodate a wider range of 3D printing materials, including plastics, metals (metal AM powders), composites, filaments, and other materials. There are numerous printing materials available for industrial additive manufacturing. Such materials have their unique characteristics, advantages, and disadvantages. In order to avoid errors in additive manufacturing, key elements such as 3D printing material type, texture, cost, printing technique and procedure, and so on must be examined. It can be complex to select the best material for a particular job. Polylactic acid (PLA) is made from sugar cane or cornstarch, both of which are renewable resources. "Black plastic" is another name for it. Because it is safe to use and print, it is frequently used in primary and secondary schools. This is also how FDM screen printing is done. PLA is simple to print because of its low warping impact. It's also possible to print it on a cold surface. When opposed to ABS, it allows for sharper edges and features to be printed. This material comes in a wide range of colours. Polylactic acid (PLA) is the most common material used in fused deposition modelling (FDM). PLA can be used to print a wide range of components, including medical implants, household items, and mechanical parts. The mechanical behaviour of the printed item is affected by variations in infill patterns that are subjected to compressive tests in the current investigation to examine their behaviour under compressive stresses.

Keywords: fused deposition modelling, polylactic acid, infill density, infill pattern, compressive strength

Procedia PDF Downloads 43
5201 Impact of Experience-Oriented Marketing on the Buying Behaviour of the Consumers: An Application in Konya Selcuk University

Authors: Ebru Esen, Ömer Akkaya, Nattanan Pankrobkaew

Abstract:

Though the experience concept found its place in the field of marketing in 1982, it is today in front of us as an important phenomenon in understanding the consumer behaviours. In parallel with the globalization and intensification of the competition, the enterprises have been in an effort to provide unique experiences for their consumers by going beyond providing services with the products. In this context, experience-oriented marketing enables the enterprises to use the marketing strategies of providing experiences for their customers and to have advantages in terms of competition. Based on it, this article discusses the concepts of experience, experience-oriented marketing and buying behaviour of consumers as a whole, and details about the application conducted in Konya Selcuklu University.

Keywords: experience, experience marketing, buying behaviour of consumers

Procedia PDF Downloads 270
5200 Control of Chaotic Behaviour in Parallel-Connected DC-DC Buck-Boost Converters

Authors: Ammar Nimer Natsheh

Abstract:

Chaos control is used to design a controller that is able to eliminate the chaotic behaviour of nonlinear dynamic systems that experience such phenomena. The paper describes the control of the bifurcation behaviour of a parallel-connected DC-DC buck-boost converter used to provide an interface between energy storage batteries and photovoltaic (PV) arrays as renewable energy sources. The paper presents a delayed feedback control scheme in a module converter comprises two identical buck-boost circuits and operates in the continuous-current conduction mode (CCM). MATLAB/SIMULINK simulation results show the effectiveness and robustness of the scheme.

Keywords: chaos, bifurcation, DC-DC Buck-Boost Converter, Delayed Feedback Control

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5199 Behaviour of Lightweight Expanded Clay Aggregate Concrete Exposed to High Temperatures

Authors: Lenka Bodnárová, Rudolf Hela, Michala Hubertová, Iveta Nováková

Abstract:

This paper is concerning the issues of behaviour of lightweight expanded clay aggregates concrete exposed to high temperature. Lightweight aggregates from expanded clay are produced by firing of row material up to temperature 1050°C. Lightweight aggregates have suitable properties in terms of volume stability, when exposed to temperatures up to 1050°C, which could indicate their suitability for construction applications with higher risk of fire. The test samples were exposed to heat by using the standard temperature-time curve ISO 834. Negative changes in resulting mechanical properties, such as compressive strength, tensile strength, and flexural strength were evaluated. Also visual evaluation of the specimen was performed. On specimen exposed to excessive heat, an explosive spalling could be observed, due to evaporation of considerable amount of unbounded water from the inner structure of the concrete.

Keywords: expanded clay aggregate, explosive spalling, high temperature, lightweight concrete, temperature-time curve ISO 834

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5198 Aging Behaviour of 6061 Al-15 vol% SiC Composite in T4 and T6 Treatments

Authors: Melby Chacko, Jagannath Nayak

Abstract:

The aging behaviour of 6061 Al-15 vol% SiC composite was investigated using Rockwell B hardness measurement. The composite was solutionized at 350°C and quenched in water. The composite was aged at room temperature (T4 treatment) and also at 140°C, 160°C, 180°C and 200°C (T6 treatment). The natural and artificial aging behaviour of composite was studied using aging curves determined at different temperatures. The aging period for peak aging for different temperatures was identified. The time required for attaining peak aging decreased with increase in the aging temperature. The peak hardness was found to increase with increase with aging temperature and the highest peak hardness was observed at 180ºC. Beyond 180ºC the peak hardness was found to be decreasing.

Keywords: 6061 Al-SiC composite, aging curve, Rockwell B hardness, T4, T6 treatments

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5197 Improving the Safety Performance of Workers by Assessing the Impact of Safety Culture on Workers’ Safety Behaviour in Nigeria Oil and Gas Industry: A Pilot Study in the Niger Delta Region

Authors: Efua Ehiaguina, Haruna Moda

Abstract:

Interest in the development of appropriate safety culture in the oil and gas industry has taken centre stage among stakeholders in the industry. Human behaviour has been identified as a major contributor to occupational accidents, where abnormal activities associated with safety management are taken as normal behaviour. Poor safety culture is one of the major factors that influence employee’s safety behaviour at work, which may consequently result in injuries and accidents and strengthening such a culture can improve workers safety performance. Nigeria oil and gas industry has contributed to the growth and development of the country in diverse ways. However, in terms of safety and health of workers, this industry is a dangerous place to work as workers are often exposed to occupational safety and health hazard. To ascertain the impact of employees’ safety and how it impacts health and safety compliance within the local industry, online safety culture survey targeting frontline workers within the industry was administered covering major subjects that include; perception of management commitment and style of leadership; safety communication method and its resultant impact on employees’ behaviour; employee safety commitment and training needs. The preliminary result revealed that 54% of the participants feel that there is a lack of motivation from the management to work safely. In addition, 55% of participants revealed that employers place more emphasis on work delivery over employee’s safety on the installation. It is expected that the study outcome will provide measures aimed at strengthening and sustaining safety culture in the Nigerian oil and gas industry.

Keywords: oil and gas safety, safety behaviour, safety culture, safety compliance

Procedia PDF Downloads 105
5196 Effect of Temperature and Deformation Mode on Texture Evolution of AA6061

Authors: M. Ghosh, A. Miroux, L. A. I. Kestens

Abstract:

At molecular or micrometre scale, practically all materials are neither homogeneous nor isotropic. The concept of texture is used to identify the structural features that cause the properties of a material to be anisotropic. For metallic materials, the anisotropy of the mechanical behaviour originates from the crystallographic nature of plastic deformation, and is therefore controlled by the crystallographic texture. Anisotropy in mechanical properties often constitutes a disadvantage in the application of materials, as it is often illustrated by the earing phenomena during drawing. However, advantages may also be attained when considering other properties (e.g. optimization of magnetic behaviour to a specific direction) by controlling texture through thermo-mechanical processing). Nevertheless, in order to have better control over the final properties it is essential to relate texture with materials processing route and subsequently optimise their performance. However, up to date, few studies have been reported about the evolution of texture in 6061 aluminium alloy during warm processing (from room temperature to 250ºC). In present investigation, recrystallized 6061 aluminium alloy samples were subjected to tensile and plane strain compression (PSC) at room and warm temperatures. The gradual change of texture following both deformation modes were measured and discussed. Tensile tests demonstrate the mechanism at low strain while PSC does the same at high strain and eventually simulate the condition of rolling. Cube dominated texture of the initial rolled and recrystallized AA6061 sheets were replaced by domination of S and R components after PSC at room temperature, warm temperature (250ºC) though did not reflect any noticeable deviation from room temperature observation. It was also noticed that temperature has no significant effect on the evolution of grain morphology during PSC. The band contrast map revealed that after 30% deformation the substructure inside the grain is mainly made of series of parallel bands. A tendency for decrease of Cube and increase of Goss was noticed after tensile deformation compared to as-received material. Like PSC, texture does not change after deformation at warm temperature though. n-fibre was noticed for all the three textures from Goss to Cube.

Keywords: AA 6061, deformation, temperature, tensile, PSC, texture

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5195 Adjustments of Mechanical and Hydraulic Properties of Wood Formed under Environmental Stresses

Authors: B. Niez, B. Moulia, J. Dlouha, E. Badel

Abstract:

Trees adjust their development to the environmental conditions they experience. Storms events of last decades showed that acclimation of trees to mechanical stresses due to wind is a very important process that allows the trees to sustain for long years. In the future, trees will experience new wind patterns, namely, more often strong winds and fewer daily moderate winds. Moreover, these patterns will go along with drought periods that may interact with the capacity of trees to adjust their growth to mechanical stresses due to wind. It is necessary to understand the mechanisms of wood functional acclimations to environmental conditions in order to predict their behaviour and in order to give foresters and breeders the relevant tools to adapt their forest management. This work aims to study how trees adjust the mechanical and hydraulic functions of their wood to environmental stresses and how this acclimation may be beneficial for the tree to resist to future stresses. In this work, young poplars were grown under controlled climatic conditions that include permanent environmental stress (daily mechanical stress of the stem by bending and/or hydric stress). Then, the properties of wood formed under these stressed conditions were characterized. First, hydraulic conductivity and sensibility to cavitation were measured at the tissue level in order to evaluate the changes in water transport capacity. Secondly, bending tests and Charpy impact tests were carried out at the millimetric scale to locally measure mechanical parameters such as elastic modulus, elastic limit or rupture energy. These experimental data allow evaluating the impacts of mechanical and water stress on the wood material. At the stem level, they will be merged in an integrative model in order to evaluate the beneficial aspect of wood acclimation for trees.

Keywords: acclimation, environmental stresses, hydraulics, mechanics, wood

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5194 Impact of Mhealth Tools on Psycho-Social Predictors of Behaviour Regarding Contraceptive Use

Authors: Preeti Tiwari, Jay Wood, Duncan Babbage

Abstract:

Family planning plays a role in saving lives across the globe by preventing unwanted pregnancies. The purpose of this multidisciplinary research was to determine the impact of mHealth tools have on psychosocial determinants of behaviour for family planning. The present study examines a topic that is very relevant in times where human-technology interaction is at its peak. It is probably one of the first studies that have investigated the impact of mobile phone technology on the underlying mechanisms of behaviour change for family planning using primary data. To examine the association between exposure to mHealth tools and predictors of behaviour, data was collected from mHealth intervention areas in India. A post-intervention quasi-experimental study with a 2x2 factorial design was conducted among 831 men and women from the state of Bihar. The quantitative data analysis evaluated the extent of influence that predictors of behaviour (beliefs, social norms, perceived behaviour control, and outcome behaviour) have on a woman’s decisions about family planning. The results indicated an association between exposure to mHealth tools and improved communication about family planning among various family members after receiving health information from a health worker (H1). A relationship between exposure to mHealth tools and increased support women received from their husbands and extended family (mothers-in-law specifically) and peers (H2) was also found. A further result showed that knowledge about family planning was greater among users of family planning (H4). mHealth tools empower women to communicate with family members. This has important implications for developing mobile phone-based tools, as they can be used as a crucial communication channel that can be an effective method of increasing communication among family members about contraceptives. Thus, it can be implied that where women feel nervous talking about contraception, the successful application of mHealth tools can strengthen the interactivity of the health communication and could increase the likelihood of using contraception. However, while it may improve health communication that can inform health decisions, it may be insufficient on its own to cause behaviour change.

Keywords: contraceptive, e-health, psycho-social, women

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5193 The Impact of Built Environment Design on Users’ Psychology to Foster Pro-Environmental Behavior in University Open Spaces

Authors: Rehab Mahmoud El Sayed, Toka Fahmy Nasr, Dalia M. Rasmi

Abstract:

Environmental psychology studies the interaction between the user and the environment. This field is crucial in understanding how the built environment affects human behaviour, moods and feelings. Studying and understanding the aspects and influences of environmental psychology is a crucial key to investigating how the design can influence human behaviour to be environmentally friendly. This is known as pro-environmental behaviour where human actions are sustainable and impacts the environment positively. Accordingly, this paper aims to explore the impact of built environment design on environmental psychology to foster pro-environmental behaviour in university campus open spaces. In order to achieve this, an exploratory research method was conducted where a detailed study of the influences of environmental psychology was done and clarified its elements. Moreover, investigating the impact of design elements on human psychology took place. Besides, an empirical study of the outdoor spaces of the British University in Egypt occurred and a survey for students and staff was distributed. The research concluded that the four main psychological aspects are mostly influenced by the following design elements colours, lighting and thermal comfort respectively. Additionally, focusing on these design elements in the design process will create a sustainable environment. As a consequence, the pro-environmental behaviour of the user will be fostered.

Keywords: environmental psychology, pro-environmental behavior, sustainable environment, psychological influences

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5192 Extending the Theory of Planned Behaviour to Predict Intention to Commute by Bicycle: Case Study of Mexico City

Authors: Magda Cepeda, Frances Hodgson, Ann Jopson

Abstract:

There are different barriers people face when choosing to cycle for commuting purposes. This study examined the role of psycho-social factors predicting the intention to cycle to commute in Mexico City. An extended version of the theory of planned behaviour was developed and utilized with a simple random sample of 401 road users. We applied exploratory and confirmatory factor analysis and after identifying five factors, a structural equation model was estimated to find the relationships among the variables. The results indicated that cycling attributes, attitudes to cycling, social comparison and social image and prestige were the most important factors influencing intention to cycle. Although the results from this study are specific to Mexico City, they indicate areas of interest to transportation planners in other regions especially in those cities where intention to cycle its linked to its perceived image and there is political ambition to instigate positive cycling cultures. Moreover, this study contributes to the current literature developing applications of the Theory of Planned Behaviour.

Keywords: cycling, latent variable model, perception, theory of planned behaviour

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5191 Bioefficacy of Ocimum sanctum on Reproductive Performance of Red Cotton Bug, Dysdercus koenigii (Heteroptera: Pyrrhocoriedae)

Authors: Kamal Kumar Gupta, Sunil Kayesth

Abstract:

Dysdercus koenigii is serious pest of cotton and other malvaceous crop. Present research work aimed at ecofriendly approach for management of pest by plant extracts. The impact of Ocimum sanctum was studied on reproductive performance of Dysdercus koenigii. The hexane extract of Ocimum leaves was prepared by ‘cold extraction method’. The newly emerged fifth instar nymphs were exposed to the extract of concentrations ranging from 0.1% to 0.00625% by ‘thin film residual method’ for a period of 24h. Reproductive fitness of the adults emerged from the treated nymphs was evaluated by assessing their courtship behaviour, oviposition behaviour, and fertility. The studies indicated that treatment of Dysdercus with the hexane extract of Ocimum altered their courtship behaviour. Consequently, the treated males exhibited less sexual activity, performed fewer mounting attempts, increased time to mate and showed decreased percent successful mating. The females often rejected courting treated male by shaking the abdomen. Similarly, the treated females in many cases remained non-receptive to the courting male. Premature termination of mating in the mating pairs prior to insemination further decreased the mating success of the treated adults. Maximum abbreviation of courtship behaviour was observed in the experimental set up where both the males and the females were treated. Only females which mate successfully were observed for study of oviposition behaviour. The treated females laid lesser number of egg batches and eggs in their life span. The eggs laid by these females were fertile indicating insemination of the female. However, percent hatchability was lesser than control. The effects of hexane extract were dose dependent. Treatment with 0.1% and 0.05% extract altered courtship behaviour. Doses of concentrations less than 0.05% did not affect courtship behaviour but altered the oviposition behaviour and fertility. Significant reduction in the fecundity and fertility was observed in the treatments at concentration as low as 0.00625%. The GCMS analysis of the extract revealed a plethora of phytochemicals including juvenile hormone mimics, and the intermediates of juvenile hormone biosynthesis. Therefore, some of these compounds individually or synergistically impair reproductive behaviour of Dysdercus. Alteration of courtship behaviour and suppression of fecundity and fertility with the help of plant extracts has wide potentials in suppression of pest population and ‘integrated pest management’.

Keywords: courtship behaviour, Dysdercus koenigii, Ocimum sanctum, oviposition behaviour

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5190 A Study on Behaviour of Normal Strength Concrete and High Strength Concrete Subjected to Elevated Temperatures

Authors: Butchi Kameswara Rao Chittem, Rooban Kumar

Abstract:

Cement concrete is a complex mixture of different materials. Concrete is believed to have a good fire resistance. Behaviour of concrete depends on its mix proportions and its constituent materials when it is subjected to elevated temperatures. Loss in compressive strength, loss in weight or mass, change in colour and spall of concrete are reported in literature as effects of elevated temperature on concrete. In this paper results are reported on the behaviour of normal strength concrete and high strength concrete subjected to temperatures 200°C, 400°C, 600°C, and 800°C and different cooling regimes viz. air cooling, water quenching. Rebound hammer test was also conducted to study the changes in surface hardness of concrete specimens subjected to elevated temperatures.

Keywords: normal strength concrete, high-strength concrete, temperature, NDT

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5189 Periodically Forced Oscillator with Noisy Chaotic Dynamics

Authors: Adedayo Oke Adelakun

Abstract:

The chaotic dynamics of periodically forced oscillators with smooth potential has been extensively investigated via theoretical, numerical and experimental simulations. With the advent of the study of chaotic dynamics by means of method of multiple time scale analysis, Melnikov theory, bifurcation diagram, Poincare's map, bifurcation diagrams and Lyapunov exponents, it has become necessary to seek for a better understanding of nonlinear oscillator with noisy term. In this paper, we examine the influence of noise on complex dynamical behaviour of periodically forced F6 - Duffing oscillator for specific choice of noisy parameters. The inclusion of noisy term improves the dynamical behaviour of the oscillator which may have wider application in secure communication than smooth potential.

Keywords: hierarchical structure, periodically forced oscillator, noisy parameters, dynamical behaviour, F6 - duffing oscillator

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5188 The Effect of Blue Lighting on Feeding Behaviour, Growth, and Corticosterone of Broiler Chickens

Authors: Sri Harimurti, Diah Reni Asih

Abstract:

This study was designated to investigate the effect of intermittent and continuous blue lighting on the feeding behaviour, growth and corticosterone hormone concentration of broiler. Two thousands and seven hundreds unsexed day-old broiler were divided into three groups of lighting treatment. Each treatment consisted of three replicates of 300 birds. The treatments were ordinary lighting (C), intermittent blue lighting (IBL) and continuous blue lighting (CBL). The data were collected in the study were feeding behaviour such as feeding duration and frequency of feeding, growth rate of birds and corticosterone hormone concentration. Results showed that the CBL have significant effect (P<0,05) on duration and frequency of feeding and growth rate of birds. The CBL have the highest feeding duration, the lowest frequency of feeding that those 290.33±1.52 minutes/day, 35.58±0.50 times/day at 15 to 28 days of age.The concentration of corticosterone hormone of IBL and CBL were a significant (P<0.05) decrease. The conclusion of this study indicated that continuous blue lighting may be a good tool for improving welfare management of broiler.

Keywords: blue light, broiler chickens, corticosterone hormone, feeding behaviour, growth rate

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5187 Environmental Education for Sustainable Development in Bangladesh and Its Challenges

Authors: Md. Kamal Uddin

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Bangladesh is trying to achieve Sustainable Development Goals (SDGs) by 2030. Environmental Education (EE) is very vital to reaching the agenda of SDGs. However, a lack of environmental awareness and gaps in theoretical knowledge and its practices still exists in Bangladesh. Therefore, this research aims to understand the students’ perceptions of whether and how their behaviour is environment-friendly to achieve SDGs. It also addresses teachers’ perceptions of what are the shortcomings of environmental education in Bangladesh. It uses the qualitative and quantitative techniques of data collection and analysis based on in-depth interviews, surveys among different categories of participants and classroom observation. The paper finds that the level of EE and students’ awareness of the environment is inadequate. Some teachers believe that the EE is not better in Bangladesh due to the absence of practical learning of EE, lack of the motivations and actions, institutional weakness, inadequate policies, poor implementation, and cultural and traditional beliefs. Thus, this paper argues that Bangladeshi EE is not adequate to change the behaviour of the students towards the environment, which makes it difficult for the country to ensure SD. Thus, this research suggests that there is a need to revise the environmental education policy to change the behaviour and structure of the country for sustainable development.

Keywords: environmental education, sustainable development, environmental practice, environmental behaviour, Bangladesh

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5186 Characterization of Shear and Extensional Rheology of Fibre Suspensions Prior to Atomization

Authors: Siti N. M. Rozali, A. H. J. Paterson, J. P. Hindmarsh

Abstract:

Spray drying of fruit juices from liquid to powder is desirable as the powders are easier to handle, especially for storage and transportation. In this project, pomace fibres will be used as a drying aid during spray drying, replacing the commonly used maltodextrins. The main attraction of this drying aid is that the pomace fibres are originally derived from the fruit itself. However, the addition of micro-sized fibres to fruit juices is expected to affect the rheology and subsequent atomization behaviour during the spray drying process. This study focuses on the determination and characterization of the rheology of juice-fibre suspensions specifically inside a spray dryer nozzle. Results show that the juice-fibre suspensions exhibit shear thinning behaviour with a significant extensional viscosity. The shear and extensional viscosities depend on several factors which include fibre fraction, shape, size and aspect ratio. A commercial capillary rheometer is used to characterize the shear behaviour while a portable extensional rheometer has been designed and built to study the extensional behaviour. Methods and equipment will be presented along with the rheology results. Rheology or behaviour of the juice-fibre suspensions provides an insight into the limitations that will be faced during atomization, and in the future, this finding will assist in choosing the best nozzle design that can overcome the limitations introduced by the fibre particles thus resulting in successful spray drying of juice-fibre suspensions.

Keywords: extensional rheology, fibre suspensions, portable extensional rheometer, shear rheology

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5185 Evaluation of Stable Isotope in Life History and Mating Behaviour of Mediterranean Fruit Fly Ceratitis capitata (Diptera: Tephidae) in Laboratory Conditions

Authors: Hasan AL-Khshemawee, Manjree Agarwal, Xin Du, Yonglin Ren

Abstract:

The possibility use of stable isotopes to study Medfly mating and life history were investigated in these experiments. 13C6 glucose was incorporated in the diet of the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephidae). Treatments included labelling and unlabelled of either the media or adult sugar water. The measured started from egg hatching till the adults have died. After mating, the adults were analysed for 13C6 glucose ratio using Liquid chromatography-mass spectrometry LC-MS in two periods of time immediately and after three days of mating. Results showed that stable isotopes were used successfully for labelling Medfly in laboratory conditions, and there were significant differences between labelled and unlabelled treatment in eggs hatching, larval development, pupae emergence, survival of adults and mating behaviour. Labelling during larval development and combined labelling of larvae and adults resulted in detectable values. The label glucose in larvae stage did not effect on mating behaviour, however, the label glucose in adults’ stage was affected by mating behaviour. We recommended that it is possible to label adults of Mediterranean fruit fly C. capitata and detected the label after mating. This method offers good tools to study mating behaviour in Medfly and other types of insects and could be providing useful tools in genetic studies, sterile insect technique (SIT) or agricultural pest management. Also, we recommended using this technique in the field.

Keywords: stable isotope, sterile insect technique (SIT), medfly, mating behaviour

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5184 The Influence of National Culture on Consumer Buying Behaviour: An Exploratory Study of Nigerian and British Consumers

Authors: Mohamed Haffar, Lombe Ngome Enongene, Mohammed Hamdan, Gbolahan Gbadamosi

Abstract:

Despite the considerable body of literature investigating the influence of National Culture (NC) dimensions on consumer behaviour, there is a lack of studies comparing the influence of NC in Africa with Western European countries. This study is intended to fill the vacuum in knowledge by exploring how NC affects consumer buyer behavior in Nigeria and the United Kingdom. The primary data were collected through in depth, semi-structured interviews conducted with three groups of individuals: British students, Nigerian students in the United Kingdom, and Nigerian-based students. This approach and new frontier to analyze culture and consumer behaviour could help understand residual cultural threads of people (that are ingrained in their being) irrespective of exposure to other cultures. The findings of this study show that Nigerian and British consumers differ remarkably in cultural orientations such as symbols, values and psychological standpoints. This ultimately affects the choices made at every stage of the decision building process, and proves beneficial for international retail marketing.

Keywords: national culture, consumer behaviour, international business, Nigeria

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5183 Effect of Hydroxyl Functionalization on the Mechanical and Fracture Behaviour of Monolayer Graphene

Authors: Akarsh Verma, Avinash Parashar

Abstract:

The aim of this article is to study the effects of hydroxyl functional group on the mechanical strength and fracture toughness of graphene. This functional group forms the backbone of intrinsic atomic structure of graphene oxide (GO). Molecular dynamics-based simulations were performed in conjunction with reactive force field (ReaxFF) parameters to capture the mode-I fracture toughness of hydroxyl functionalised graphene. Moreover, these simulations helped in concluding that spatial distribution and concentration of hydroxyl functional group significantly affects the fracture morphology of graphene nanosheet. In contrast to literature investigations, atomistic simulations predicted a transition in the failure morphology of hydroxyl functionalised graphene from brittle to ductile as a function of its spatial distribution on graphene sheet.

Keywords: graphene, graphene oxide, ReaxFF, molecular dynamics

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5182 Evaluation of the Impact of Functional Communication Training on Behaviors of Concern for Students at a Non-Maintained Special School

Authors: Kate Duggan

Abstract:

Introduction: Functional Communication Training (FCT) is an approach which aims to reduce behaviours of concern by teaching more effective ways to communicate. It requires identification of the function of the behaviour of concern, through gathering information from key stakeholders and completing observations of the individual’s behaviour including antecedents to, and consequences of the behaviour. Appropriate communicative alternatives are then identified and taught to the individual using systematic instruction techniques. Behaviours of concern demonstrated by individuals with autism spectrum conditions (ASC) frequently have a communication function. When contributing to positive behavior support plans, speech and language therapists and other professionals working with individuals with ASC need to identify alternative communicative behaviours which are equally reinforcing as the existing behaviours of concern. Successful implementation of FCT is dependent on an effective ‘response match’. The new way of communicating must be equally as effective as the behaviour previously used and require the same amount or less effort from the individual. It must also be understood by the communication partners the individual encounters and be appropriate to their communicative contexts. Method: Four case studies within a non-maintained special school environment were described and analysed. A response match framework was used to identify the effectiveness of functional communication training delivered by the student’s speech and language therapist, teacher and learning support assistants. The success of systematic instruction techniques used to develop new communicative behaviours was evaluated using the CODES framework. Findings: Functional communication training can be used as part of a positive behaviour support approach for students within this setting. All case studies reviewed demonstrated ‘response success’, in that the desired response was gained from the new communicative behaviour. Barriers to the successful embedding of new communicative behaviours were encountered. In some instances, the new communicative behaviour could not be consistently understood across all communication partners which reduced ‘response recognisability’. There was also evidence of increased physical or cognitive difficulty in employing the new communicative behaviour which reduced the ‘response effectivity’. Successful use of ‘thinning schedules of reinforcement’, taught students to tolerate a delay to reinforcement once the new communication behaviour was learned.

Keywords: augmentative and alternative communication, autism spectrum conditions, behaviours of concern, functional communication training

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5181 Mechanical Behaviour of High Strength Steel Thin-Walled Profiles for Automated Rack Supported Warehouses

Authors: Agnese Natali, Francesco Morelli, Walter Salvatore, José Humberto Matias de Paula Filho, Patrick Pol

Abstract:

In the framework of the evaluation of the applicability of high strength steel to produce thin-walled elements to be used in Automated Rack Supported Warehouses, an experimental campaign is carried outto evaluate the structural performance of typical profile shapes adopted for such purposes and made of high strength steel. Numerical models are developed to fit the observed failure modes, stresses, and deformation patterns, and proper directions are proposed to simplify the numerical simulations to be used in further applications and to evaluate the mechanical behavior and performance of profiles.

Keywords: Steel racks, Automated Rack Supported Warehouse, thin walled cold-formed elements, high strength steel.

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5180 Finite Deformation of a Dielectric Elastomeric Spherical Shell Based on a New Nonlinear Electroelastic Constitutive Theory

Authors: Odunayo Olawuyi Fadodun

Abstract:

Dielectric elastomers (DEs) are a type of intelligent materials with salient features like electromechanical coupling, lightweight, fast actuation speed, low cost and high energy density that make them good candidates for numerous engineering applications. This paper adopts a new nonlinear electroelastic constitutive theory to examine radial deformation of a pressurized thick-walled spherical shell of soft dielectric material with compliant electrodes on its inner and outer surfaces. A general formular for the internal pressure, which depends on the deformation and a potential difference between boundary electrodes or uniform surface charge distributions, is obtained in terms of special function. To illustrate the effects of an applied electric field on the mechanical behaviour of the shell, three different energy functions with distinct mechanical properties are employed for numerical purposes. The observed behaviour of the shells is preserved in the presence of an applied electric field, and the influence of the field due to a potential difference declines more slowly with the increasing deformation to that produced by a surface charge. Counterpart results are then presented for the thin-walled shell approximation as a limiting case of a thick-walled shell without restriction on the energy density. In the absence of internal pressure, it is obtained that inflation is caused by the application of an electric field. The resulting numerical solutions of the theory presented in this work are in agreement with those predicted by the generally adopted Dorfmann and Ogden model.

Keywords: constitutive theory, elastic dielectric, electroelasticity, finite deformation, nonlinear response, spherical shell

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5179 A Quick Prediction for Shear Behaviour of RC Membrane Elements by Fixed-Angle Softened Truss Model with Tension-Stiffening

Authors: X. Wang, J. S. Kuang

Abstract:

The Fixed-angle Softened Truss Model with Tension-stiffening (FASTMT) has a superior performance in predicting the shear behaviour of reinforced concrete (RC) membrane elements, especially for the post-cracking behaviour. Nevertheless, massive computational work is inevitable due to the multiple transcendental equations involved in the stress-strain relationship. In this paper, an iterative root-finding technique is introduced to FASTMT for solving quickly the transcendental equations of the tension-stiffening effect of RC membrane elements. This fast FASTMT, which performs in MATLAB, uses the bisection method to calculate the tensile stress of the membranes. By adopting the simplification, the elapsed time of each loop is reduced significantly and the transcendental equations can be solved accurately. Owing to the high efficiency and good accuracy as compared with FASTMT, the fast FASTMT can be further applied in quick prediction of shear behaviour of complex large-scale RC structures.

Keywords: bisection method, FASTMT, iterative root-finding technique, reinforced concrete membrane

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5178 Bridging the Gap and Widening the Divide

Authors: Lerato Dixon, Thorsten Chmura

Abstract:

This paper explores whether ethnic identity in Zimbabwe leads to discriminatory behaviour and the degree to which a norm-based intervention can shift this discriminatory behaviour. Social Identity Theory suggests that group identity can lead to favouritism towards the in-group and discriminatory behaviour towards the out-group. Agents yield higher utility from maintaining positive self-esteem by confirming with group behaviour. This paper focuses on the two majority ethnic groups in Zimbabwe – the Ndebele and Shona. Racial identities are synonymous with the language spoken. Zimbabwe’s history highlights how identity formation took place. As following independence, political parties became recognised as either Ndebele or Shona-speaking. It is against this backdrop that this study investigates the degree to which norm-based nudge can alter behaviour. This paper uses experimental methods to analyse discriminatory behaviour between two naturally occurring ethnic groups in Zimbabwe. In addition, we investigate if social norm-based interventions can shift discriminatory behaviour to understand if the divide between these two identity groups can be further divided or healed. Participants are randomly assigned into three groups to receive information regarding a social norm. We compare the effect of a proscriptive social norm-based intervention, stating what shouldn't be done and prescriptive social norms as interventions, stating what should be done. Specifically, participants are either shown the socially appropriate (Heal) norm, the socially inappropriateness (Divide) norm regarding interethnic marriages or no norm-based intervention. Following the random assignment into intervention groups, participants take part in the Trust Game. We conjecture that discrimination will shift in accordance with the prevailing social norm. Instead, we find evidence of interethnic discriminatory behaviour. We also find that trust increases when interacting with Ndebele, Shona and Zimbabwean participants following the Heal intervention. However, if the participant is Shona, the Heal intervention decreases trust toward in-groups and Zimbabwean co-players. On the other hand, if the participant is Shona, the Divide treatment significantly increases trust toward Ndebele participants. In summary, we find evidence that norm-based interventions significantly change behaviour. However, the prescriptive norm-based intervention (Heal) decreases trust toward the in-group, out-group and national identity group if the participant is Shona – therefore having an adverse effect. In contrast, the proscriptive Divide treatment increases trust if the participant is Shona towards Ndebele co-players. We conclude that norm-based interventions have a ‘rebound’ effect by altering behaviour in the opposite direction.

Keywords: discrimination, social identity, social norm-based intervention, zimbabwe

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5177 Role of Amount of Glass Fibers in PAEK Composites to Control Mechanical and Tribological Properties

Authors: Jitendra Narayan Panda, Jayashree Bijwe, Raj K. Pandey

Abstract:

PAEK (Polyaryl ether ketone) being a high-performance polymer, is currently being explored for its tribo-potential by incorporating various fibers, solid lubricants. In this work, influence of amount (30 and 40 %) of short glass fibers (GF) in two composites containing PAEK (60 and 50 %) and synthetic graphite (10 %) on mechanical and tribological behaviour was studied. The composites were developed by injection molding and evaluated in adhesive wear mode (pin on disc configuration) against mild steel disc. The load and speed were selected as variable input parameters while coefficient of friction (µ), specific wear rate (K0) and PVlimit (pressure × velocity) values were selected as output parameters for performance evaluation. Although higher amount of GF lead to better mechanical properties, tribological properties were not in tune to this. Overall, µ and K0 for both composites were in the range 0.04-0.08 and 3-8x 10-16 m3/Nm respectively and decreased with increase in applied PV values till failure was observed. PVlimit was indicated by 112 and 100 MPa m/s. Such high PVlimit values are not reported for any polymer composites running in dry conditions in the literature. The mechanical properties of the C40 composite (40 % GF) proved superior to C30 composite (30 % GF). However, all tribological properties of C40 were inferior to C30. It exhibited higher µ, higher K0 and slightly lower PVlimit value. The higher % fibers proved detrimental for tribo-performance and worn surface analysis by SEM & EDAX was done on the discs & pins to understand wear mechanisms.

Keywords: PAEK composites, pin-on-disk, PV limit, friction

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5176 Component Test of Martensitic/Ferritic Steels and Nickel-Based Alloys and Their Welded Joints under Creep and Thermo-Mechanical Fatigue Loading

Authors: Daniel Osorio, Andreas Klenk, Stefan Weihe, Andreas Kopp, Frank Rödiger

Abstract:

Future power plants currently face high design requirements due to worsening climate change and environmental restrictions, which demand high operational flexibility, superior thermal performance, minimal emissions, and higher cyclic capability. The aim of the paper is, therefore, to investigate the creep and thermo-mechanical material behavior of improved materials experimentally and welded joints at component scale under near-to-service operating conditions, which are promising for application in highly efficient and flexible future power plants. These materials promise an increase in flexibility and a reduction in manufacturing costs by providing enhanced creep strength and, therefore, the possibility for wall thickness reduction. At the temperature range between 550°C and 625°C, the investigation focuses on the in-phase thermo-mechanical fatigue behavior of dissimilar welded joints of conventional materials (ferritic and martensitic material T24 and T92) to nickel-based alloys (A617B and HR6W) by means of membrane test panels. The temperature and external load are varied in phase during the test, while the internal pressure remains constant. At the temperature range between 650°C and 750°C, it focuses on the creep behavior under multiaxial stress loading of similar and dissimilar welded joints of high temperature resistant nickel-based alloys (A740H, A617B, and HR6W) by means of a thick-walled-component test. In this case, the temperature, the external axial load, and the internal pressure remain constant during testing. Numerical simulations are used for the estimation of the axial component load in order to induce a meaningful damage evolution without causing a total component failure. Metallographic investigations after testing will provide support for understanding the damage mechanism and the influence of the thermo-mechanical load and multiaxiality on the microstructure change and on the creep and TMF- strength.

Keywords: creep, creep-fatigue, component behaviour, weld joints, high temperature material behaviour, nickel-alloys, high temperature resistant steels

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5175 An Interpretive Study of Entrepreneurial Experience towards Achieving Business Growth Using the Theory of Planned Behaviour as a Lens

Authors: Akunna Agunwah, Kevin Gallimore, Kathryn Kinmond

Abstract:

Entrepreneurship is widely associated and seen as a vehicle for economic growth; however, different scholars have studied entrepreneurship from various perspectives, resulting in multiple definitions. It is surprising to know most entrepreneurship definition does not incorporate growth as part of their definition of entrepreneurship. Economic growth is engineered by the activities of the entrepreneurs. The purpose of the present theoretical study is to explore the working practices of the successful entrepreneurs towards achieving business growth by understanding the experiences of the entrepreneur using the Theory of Planned Behaviour (TPB) as a lens. Ten successful entrepreneurs in the North West of England in various business sectors were interviewed using semi-structured interview method. The recorded audio interviews transcribed and subsequently evaluated using the thematic deductive technique (qualitative approach). The themes were examined using Theory of Planned Behaviour to ascertain the presence of the three intentional antecedents (attitude, subjective norms, and perceived behavioural control). The findings categorised in two folds, firstly, it was observed that the three intentional antecedents, which make up Theory of Planned Behaviour were evident in the transcript. Secondly, the entrepreneurs are most concerned with achieving a state of freedom and realising their visions and ambitions. Nevertheless, the entrepreneur employed these intentional antecedents to enhance business growth. In conclusion, the work presented here showed a novel way of understanding the working practices and experiences of the entrepreneur using the theory of planned behaviour in qualitative approach towards enhancing business growth. There exist few qualitative studies in entrepreneurship research. In addition, this work applies a novel approach to studying the experience of the entrepreneurs by examining the working practices of the successful entrepreneurs in the North-West England through the lens of the theory of planned behaviour. Given the findings regarding TPB as a lens in the study, the entrepreneur does not differentiate between the categories of the antecedents reasonably sees them as processes that can be utilised to enhance business growth.

Keywords: business growth, experience, interpretive, theory of planned behaviour

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