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Analysis of mechanical power flow in an electric drive operating under vibration conditions
Get PDFThis paper discusses the analysis of mechanical power flow in an electric motor drive operating under variation of conditions. The drive system vibration generates the oscillation in the supplied active power which can reduce performance of the system and increase the actual load on the shaft. It is shown that the vibration damper installation significantly decreases the oscillations in mechanical power flow on the motor shaft and improves characteristics of the system operation. The paper provide analysis of two models of the electric drive installed on the platform - the system which is quipped with vibration dampers and without
Modelling and thermal analysis of advanced insulating layer electronic applications
Get PDFThis paper proposes the replacement of a conventional Insulating-Metal-Substrate (IMS) dielectric layer with an electroconductive adhesive which is applied onto a treated aluminium heat sink. The adhesive based structure results in a lower thermal resistance of the system compared to IMS based on Aluminium. The model covers the investigation of two IMS structure with a Copper conductor layer with a thickness of 200μm, a dielectric layer of 50μm with different thermal conductivities and an Aluminium base layer with a thickness of 920μm. However, the IMS is placed onto a 100 x 100 x 33 mm Aluminium heat sink. The investigated adhesive based structure consists of the same Aluminium heat sink treated with an oxidation layer with a thickness of 50μm and an adhesive conductor layer with 30μm thickness. Furthermore, the use of forced convection to reduce the junction temperature of all three models is also considered
The interfacial, emulsification and encapsulation properties of hydrophobically modified inulin
Get PDFOctenyl- and dodecenyl succinic anhydride derivatives (OSA- and DDSA-) of inulin have been synthesised and their solution and interfacial properties have been determined and compared to a commercially available alkylated inulin, Inutec SP1. All samples formed micellar aggregates in solution above a critical concentration (critical aggregation concentration) and were able to ‘dissolve’ a hydrophobic dye. They were also able to form stable oil-in-water (O/W) emulsions as assessed by measurements of their droplet size as a function of time. DDSA-inulin with a high degree of substitution was found to be effective at encapsulating beta carotene using the solvent evaporation method which yielded a solid which dissolved readily in simulated gastric fluid. The results confirm the potential application of these materials in a number of areas including, drug delivery, pharmaceuticals, neutraceuticals, cosmetics and personal care
Interfacial and emulsifying properties of the electrostatic complex of β-lactoglobulin fibril and gum Arabic (Acacia Seyal)
Get PDFFormation, interfacial and emulsifying properties of the electrostatic complex of β-lactoglobulin fibril (BLGF) and gum Arabic Acacia Seyal (AS) were investigated. Necklace-like soluble complex could be formed at pH 3.5, and its charge and interfacial properties depended on the BLGF content. With appropriate amount of BLGF (< 9.09 wt.%), the formed complex possessed a good dispersibility and surface activity. When excessive BLGF (9.09∼50 wt.%) existed, surface charge of the complex was gradually neutralized and aggregation occurred. Homogeneous oil-in-water emulsions could be stabilized by the complex and the droplet size decreased with increasing BLGF content. Higher content of BLGF (9.09∼50 wt.%) was detrimental for emulsification due to the aggregation of complex, and the formed emulsion tended to flocculate. Compared with AS, the complex formed emulsions were much more stable against heating (90 ℃, 30 min) and salting (200 mM NaCl) environments, and the emulsions were stable during long-term storage (46 days).
Proposed mechanisms for the adsorption of BLGF/AS complex at the oil-water interface. Pure AS (i) could adsorb at the oil-water interface but formed a loose film due to its poor surface activity and insufficient adsorption amount. With addition of a small amount of fibrils (ii), soluble electrostatic complexes are formed and they can be adsorbed at the interface to formed a dense viscoelastic film due to the surface activity of the BLGF. With a higher content of fibrils (iii), surface charge of the complex tended to be neutralized, causing the aggregation. Because the presence of protein fibrils, they could also adsorb at the oil-water interface to produce a viscoelastic film. However, with a bigger size and irregular shape, the aggregates were difficult to array at the interface as densely as the soluble complex
Review of electrically powered propulsion for aircraft
Get PDFThis paper presents a review of the state-of-the-art in aircraft electrical propulsion technology. A comparison is provided of differing propulsion mechanisms such as propellers, open fans, ducted fans, multi-stage rim driven fans and distributed thrust designs and their suitability to particular flight profiles and mission applications. Electrical motor architectures are also reviewed with particular attention being given to synchronous machines, such as Brushless Direct Current (BLDC) and Switched Reluctance Motor (SRM) technologies, and the recent advances that have been made in solid-state switching and High Temperature Superconducting (HTS) material applications. Present day electrical power generation, storage and control technologies are also reviewed including hybrid and fuel cell technologies and regeneration techniques. Electrical storage capabilities with regard to specific power and energy characteristics are discussed and the extent to which existing system technology can be integrated onto a Hybrid-electric and an All Electric Aircraft (AEA) is also investigated. Finally, a conclusion is provided highlighting the current technological challenges facing the development of commercial aircraft in terms of performance, airframe configuration and legislative and operational infrastructural requirements
Performance Analysis of a Wearable Photovoltaic System
Get PDFThis paper discusses the results obtained during the practical characterization of the piezo electric properties of a commonly used carbon fibre. The aim of the investigation was to prepare the grounds for the feasibility of a low cost impact sensor that could be included in any carbon fibre structure (megalithic or thin structure) without interfering the integrity of the actual structure itself. The entire measurement loop as well as the techniques of connectivity of the fibres to the loop is described within. The piezo electric effects and all factors which affect the measurements are reflected in the analysis. The results obtained shown that in normal laboratory conditions the piezo-electric response of a T300 carbon fibre is consistent and directly proportional to the impact applied to the fibre
Auditory masking and the Precedence Effect in Studies of Musical Timekeeping
Get PDFMusical timekeeping is an important and evolving area of research with applications in a variety of music education and performance situations. Studies in this field are of ten concerned with being able to measure the accuracy or consistency of human participants, for whatever purpose is being investigated. Our initial explorations suggest that little has been done to consider the role that auditory masking, specifically the precedence effect, plays in the study of human timekeeping tasks. In this paper, we highlight the importance of integrating masking into studies of timekeeping and suggest areas for discussion and future research, to address shortfalls in the literature
FinTech (Financial Technology): What is It and How to Use Technologies to Create Business Value in Fintech Way?
Get PDFWe define FinTech as a cross-disciplinary subject that combines Finance, Technology Management and Innovation Management. The definition had been presented to different audiences with different backgrounds, such as students and business professionals in various events, we found that the definition provides audiences better understanding on what is FinTech and its potential. Moreover, in order to discuss how FinTech would create value for businesses, we summarized various FinTech applications into four major categories: i) payment, ii) advisory service, iii) financing and iv) compliance. In addition, we also discuss what are the emerging technologies in FinTech and how they could possibility create business values. We believe that this study could serve as a reference for researchers, particularly from technology background, on how to identify and develop new Fintech solutions
Psychometric properties of three measures of “Facebook engagement and/or addiction” among a sample of English speaking Pakistani university students
Get PDFFor researchers interested in measuring the construct of “Facebook engagement and/or addiction,” there are a number of existing measures including the Bergen Facebook Addiction Scale, the Facebook Intensity Scale, and the Addictive Tendencies Scale. Currently, there is limited data on the psychometric properties of these three scales, especially among South Asian samples. The present aim was to address this shortfall. A sample of 308 English-speaking Pakistani university students completed the scales, in their original English versions, on two occasions separated by four weeks. Results demonstrated that for each of the scales, across both administrations, satisfactory psychometric properties were found, including internal reliability, temporal stability, and construct validity. Moreover, for these three scales, using confirmatory factor analysis, a one-factor structure was generally found to be a good description of the data for both male and female samples. These data provide further evidence for the reliability and validity of three scales concerned with “Facebook engagement and/or addiction.
Meditation on the Soles of the Feet Practice Provides Some Control of Aggression for Individuals with Alzheimer’s Disease
Get PDFAlzheimer’s disease is a progressive neurodegenerative condition that affects cognition, mental and physical health, and functionality of older people. As the disease progresses from the mild to moderate stage, there is a concomitant increase in several behavioral variables, chiefly agitation, anger, and aggression. Currently, there are no evidence-based treatments for these behaviors in this population. Three individuals with moderate Alzheimer’s disease were taught an informal mindfulness practice, meditation on the Soles of the Feet (SoF), as a self-management strategy within a multiple-baseline design across participants. All three were able to learn and use the SoF practice to manage their verbal and physical aggression. Their use of the SoF practice was correlated with decreased perceived psychological stress for their spouses and caregivers, as well as for the participants, but to a much smaller degree. In terms of social validity, the participants, their spouses, and caregivers rated the SoF practice as acceptable, effective, with no unintended effects, and indicated that they would recommend the practice to others. However, they also rated SoF as effortful for the participants because it involves the participants remembering to use the practice with rising anger, a requirement particularly challenging for those with memory problems. The SoF practice may enable individuals in the early stages of dementia to manage their anger and aggression. The data were derived from an internally valid experimental design, suggestive of initial proof-of-concept, but needs to be replicated before any clinical implications can be imputed from this study