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1 – 10 of over 2000Yue Liu and Jiayu Gong
The purpose of this paper is to investigate the thermal elastohydrodynamic lubrication (TEHL) flash temperature of the helical gear pairs considering profile modification.
Abstract
Purpose
The purpose of this paper is to investigate the thermal elastohydrodynamic lubrication (TEHL) flash temperature of the helical gear pairs considering profile modification.
Design/methodology/approach
A flash temperature model of the helical gear pair considering the profile modification is proposed based on the TEHL and meshing theories. In doing so, the slicing, fast Fourier transform and chase-after methods are applied to accurately and rapidly obtain the flash temperature of the gear pair. Then, the effects of the modification, input torque and rotation speed on the flash temperature are studied.
Findings
With the increment of the tip relief amount, the flash temperature of the helical gear pair with the axial modification decreases first and then increases, and the meshing position of the maximum flash temperature moves toward the pitch point. Moreover, reducing the input torque or increasing the rotation speed can efficiently reduce the TEHL flash temperature.
Originality/value
This work is a valuable reference for the profile design and optimization of the helical gears to avoid the excessive flash temperature.
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Roberto Salvatore Di Fede, Marivel Gonzalez-Hernandez, Eva Parga-Dans, Pablo Alonso Gonzalez, Purificación Fernández-Zurbano, María Cristina Peña del Olmo and María-Pilar Sáenz-Navajas
The main aim of this study is to characterise and identify specific chemo-sensory profiles of ciders from the Canary Islands (Spain).
Abstract
Purpose
The main aim of this study is to characterise and identify specific chemo-sensory profiles of ciders from the Canary Islands (Spain).
Design/methodology/approach
Commercial samples of Canary ciders were compared to ciders from the Basque Country and Asturias. In total, 18 samples were studied, six for each region. The analysis comprised their sensory profiling and chemical characterisation of their polyphenolic profile, volatile composition, conventional chemical parameters and CIELAB colour coordinates. In parallel, the sensory profile of the samples from the Canary Islands was first compared with their Basque and Asturian counterparts by labelled sorting task. Then, their specific aroma profile was characterised by flash profile. Further quantification of sensory-active compounds was performed by GC–MS and GC-FID to identify the volatile compounds involved in their aroma profile.
Findings
Results show that Canary ciders present a specific chemical profile characterised by higher levels of ethanol, and hydroxycinnamic acids, mainly t-ferulic, t-coumaric and neochologenic acids, and lower levels of volatile and total acidity than their Asturian and Basque counterparts. They also present a specific aroma profile characterised by fruity aroma, mainly fruit in syrup and confectionary, and sweet flavours related to their highest levels of vinylphenols formed by transformation of hydroxycinnamic acids.
Originality/value
An integrated strategy to explore the typicity of the currently existing Canary ciders in the market was developed. The results are important in that they will help other regions to identify specific typical chemo-sensory profiles and to promote the creation of certifications supporting regional typicity.
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Bousmaha Baiche, Chris Kendrick and Ray Ogden
The purpose of this paper is based on recent research at Oxford Brookes University which explored how metal building envelopes can provide high levels of air‐tightness.
Abstract
Purpose
The purpose of this paper is based on recent research at Oxford Brookes University which explored how metal building envelopes can provide high levels of air‐tightness.
Design/methodology/approach
An intensive research programme tested many of the foremost cladding systems used in the UK. Over 500 individual tests have produced reliable data on the performance of different joint types. This paper summarises that data and identifies key design issues and solutions.
Findings
The research has demonstrated that metal building envelopes can provide very high levels of air‐tightness providing that they are properly engineered and assembled. It also presents compelling evidence, based on whole building thermal dynamic simulations using the test data, that further increases in air‐tightness are achievable; far more energy can be saved by doing this than by increasing thermal insulation even further.
Research limitations/implications
The testing programme concentrated on steel cladding systems, both built‐up and composite panels, with technical assessment of different joints assemblies using a dedicated purpose‐built air‐tightness test rig.
Practical implications
As this research and other studies have shown that far more energy can be saved by achieving high levels of air‐tightness than by increasing thermal insulation even further, it suggests that a major change in regulatory strategy is now due.
Originality/value
The value of the paper lies in the originality of the testing programme and method. Although BSRIA has been testing whole completed buildings for air‐tightness using large mobile fan units pressurising the building to 50 Pa, it is the first time that a variety of cladding systems have been tested for air‐tightness on a large scale and in a laboratory environment; BRE carried out air‐tightness testing on few steel cladding systems on a smaller scale.
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Kamel Ettaieb, Sylvain Lavernhe and Christophe Tournier
This paper aims to propose an analytical thermal three-dimensional model that allows an efficient evaluation of the thermal effect of the laser-scanning path. During manufacturing…
Abstract
Purpose
This paper aims to propose an analytical thermal three-dimensional model that allows an efficient evaluation of the thermal effect of the laser-scanning path. During manufacturing by laser powder bed fusion (LPBF), the laser-scanning path influences the thermo-mechanical behavior of parts. Therefore, it is necessary to validate the path generation considering the thermal behavior induced by this process to improve the quality of parts.
Design/methodology/approach
The proposed model, based on the effect of successive thermal flashes along the scanning path, is calibrated and validated by comparison with thermal results obtained by FEM software and experimental measurements. A numerical investigation is performed to compare different scanning path strategies on the Ti6Al4V material with different stimulation parameters.
Findings
The simulation results confirm the effectiveness of the approach to simulate the thermal field to validate the scanning strategy. It suggests a change in the scale of simulation thanks to high-performance computing resources.
Originality/value
The flash-based approach is designed to ensure the quality of the simulated thermal field while minimizing the computational cost.
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Arunothai Juemanee, Kongkarn Kijroongrojana, Mutita Meenune and Wilatsana Posri
The purpose of this paper is to explore and compare consumer perceptions of unpolished pigmented rice and milled white rice between unfamiliar and typical consumers.
Abstract
Purpose
The purpose of this paper is to explore and compare consumer perceptions of unpolished pigmented rice and milled white rice between unfamiliar and typical consumers.
Design/methodology/approach
This study first employed focus groups to explore attitudes and habits relating to rice consumption among British subjects. A sensory descriptive analysis method, flash profiling (FP), was then applied on consumer panels in the UK and Thailand to gain perceived sensory quality of unfamiliar and typical rice samples. The sensory profiles generated by British and Thai panellists were analysed by generalised procrustean analysis (GPA) and compared based on perceived attributes, dominant characteristics and repeatability.
Findings
Focus group results suggested that consumer familiarity with rice might influence preferred rice textural quality. The prominent textures of stickiness and bittiness of unpolished pigmented rice were negatively associated with perceived quality in the UK participants. The sensory profiles generated by GPA consisted of similarity with darkness of colour and sweet/earthy type odours that are key dominant characteristics of the Thai pigmented rice.
Practical implications
The research has provided sensory information of the unpolished pigmented rice as compared with milled white rice. The information gives insights on product development directions for export and further research on rice processing and cooking instructions.
Originality/value
This study is the first to apply sensory evaluation in a cross-cultural comparison of pigmented rice.
Details
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Mary Lou Strong, Ladonna Guillot and Jean Badeau
Senior CHAT (Consumer Health Awareness Training) improved health information literacy and promoted better health outcomes through basic computer instruction among senior citizens…
Abstract
Purpose
Senior CHAT (Consumer Health Awareness Training) improved health information literacy and promoted better health outcomes through basic computer instruction among senior citizens in a healthcare impoverished Louisiana parish. Librarians at a state university in southeast Louisiana partnered with senior citizen centers to promote National Library of Medicine databases in a project funded by National Network/Libraries of Medicine/South Central Region. This paper seeks to describe and discuss this initiative.
Design/methodology/approach
Librarians responded to a community assessment demonstrating the need for basic computer instruction and increased health information literacy among the 1,800 clients served by the Tangipahoa Voluntary Council on Aging (TVCOA). Senior CHAT included two series of hands‐on classes with 25 students. Seniors were instructed in the use of MedlinePlus and NIHSeniorHealth databases. TVCOA staff were trained to continue to assist seniors after the project's completion. A Senior Citizen Consumer Health LibGuide was created and is a project legacy. Participants also created updatable portable personal health profiles.
Findings
Pre‐ and post‐instruction surveys suggest seniors increased usage of the databases post‐instruction. Over 70 percent of senior participants were able to create a personal health profile.
Social implications
The elderly are at risk of poor health literacy. As the USA moves to a consumer‐centric health care system, these individuals need technology skills to take an active role in health care‐related decisions.
Originality/value
The project promoted lifelong learning in the region and forged new community partnerships. Its value lies in its reproducibility in a variety of community settings and its alignment with US Healthy People 2020 initiatives.
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Hakan Kaleli and Irfan Yavasliol
The more frequently an engine oil is changed, the more the overhaul life of the engine is extended but with an increase in the cost both of the oil and of the oil drain services…
Abstract
The more frequently an engine oil is changed, the more the overhaul life of the engine is extended but with an increase in the cost both of the oil and of the oil drain services. If engine oil is changed less frequently the associated costs will decrease. In order to find the optimum drain interval, it is necessary to establish the relationship between the cost of the oil and oil drain services and the cost of more frequent overhauls. Presents an investigation into the degradation of a proprietary lubricant marketed in Turkey, and the wear rate of a petrol engine driven in urban traffic. Lubricant samples were examined approximately every 2,000km for deterioration of the lubricant and evidence of wear of the engine components. From the experimental results, determines the optimum oil drain period of the engine.
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Nitin Panaskar and Ravi Prakash Terkar
Recently, several studies have been performed on lap welding of aluminum and copper using friction stir welding (FSW). The formation of intermetallic compounds at the weld…
Abstract
Purpose
Recently, several studies have been performed on lap welding of aluminum and copper using friction stir welding (FSW). The formation of intermetallic compounds at the weld interface hampers the weld quality. The use of an intermediate layer of a compatible material during welding reduces the formation of intermetallic compounds. The purpose of this paper is to optimize the FSW process parameters for AA6063-ETP copper weld, using a compatible zinc intermediate filler metal.
Design/methodology/approach
In the present study, a three-level, three-factor central composite design (CCD) has been used to determine the effect of various process parameters, namely, tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil on ultimate tensile strength of the weld. A total of 60 experimental data were fitted in the CCD. The experiments were performed with tool rotational speeds of 1,000, 1,200 and 1,400 rpm each of them with tool traverse speeds of 5, 10 and 15 mm/min. A zinc inter-filler foil of 0.2 and 0.4 mm was also used. The macrograph of the weld surface under different process parameters and the tensile strength of the weld have been investigated.
Findings
The feasibility of joining 3 mm thick AA6063-ETP copper using zinc inter-filler is established. The regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination (R2) value of 0.9759 and model F-value of 240.33. A good agreement between the prediction model and experimental findings validates the reliability of the developed model. The tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil significantly affected the tensile strength of the weld. The optimal conditions found for the weld were, rotational speed of 1,212.83 rpm and traverse speed of 9.63 mm/min and zinc foil thickness is 0.157 mm; by using optimized values, ultimate tensile strength of 122.87 MPa was achieved, from the desirability function.
Originality/value
Aluminium and copper sheets could be joined feasibly using a zinc inter-filler. The maximum tensile strength of joints formed by inter-filler (122.87 MPa) was significantly better as compared to those without using inter-filler (83.78 MPa). The optimum process parameters to achieve maximum tensile strength were found by CCD.
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Anna K. Zarkada and Christina Polydorou
This chapter expands traditional approaches to Corporate Reputation Management by employing postmodernist approaches to value co-creation in order to identify how Facebook…
Abstract
Purpose
This chapter expands traditional approaches to Corporate Reputation Management by employing postmodernist approaches to value co-creation in order to identify how Facebook Features can be used to facilitate company–consumer Corporate Reputation co-creation.
Methodology/approach
Using content analysis of Facebook Fan Pages, the chapter explores how 29 of the world’s most reputable corporations use Facebook Features.
Findings
To a surprising degree, the corporations in the sample, despite having virtually limitless access to marketing communications resources, fail to make full use of the opportunities Facebook offers them. It appears that they have not yet fully adapted to this novel medium.
Research implications
Facebook together with the locus has also shifted the focus of corporate communications from one-way company-controlled transmission of information to multiparty user-controlled conversations. Thus, Corporate Reputations can no longer be managed. Instead, by offering consumers experiences and emotional triggers, corporations can engage them into willingly marketing the corporation and its products to each other.
Originality/value of chapter
This is the first systematic analysis of the practices the world’s most prominent corporations utilize (or fail to employ) on Facebook. It illustrates that companies that adapt to the Social Media ecology can successfully orchestrate customer experiences that foster the co-creation of the desired Corporate Reputation.
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Lin Dong, Florian Richer, Agnes Roby-Brami and Guillaume Morel
When a robot comanipulates an object with a human user, damping is a useful function. This is achieved by programming the robot to exhibit a viscous field. For some specific…
Abstract
Purpose
When a robot comanipulates an object with a human user, damping is a useful function. This is achieved by programming the robot to exhibit a viscous field. For some specific applications, the viscosity is required to change according to the manipulation velocity. A reported method is programming the viscosity varying inversely to the velocity. In this paper, this method is experimentally shown to distort human’s natural motion performance. This paper aims to propose a solution to solve this instability problem.
Design/methodology/approach
The authors performed a point-to-point targeting movement, where it was observed that the instability results from a sudden reduction of robot’s resistance to motion, which further results from the abrupt viscosity drop when the subject tries to accelerate. Therefore, the authors propose a solution where a first-order linear filter is added to the viscosity coefficient so as to slow down its variation.
Findings
The experimental results confirm that the proposition is effective, with the ability to stabilize the comanipulated dynamics and to restore the human’s natural behavior.
Originality/value
This paper concerns applications of comanipulation where the viscosity coefficient is designed to decrease as the velocity increases. An instability problem, which was of vital importance in terms of safety and performance but unreported in the literature, was experimentally studied through human–robot experiments. A solution was proposed by including a secondary dynamics in the variations of the viscosity. Its effectiveness was supported by the practical point-to-point motion experiments.
Details