365 research outputs found

    Energy absorption capability of thin-walled aluminium tubes under crash loading

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    This paper investigates the interaction of design factors such as tube thickness, tube length, and tube cross-sectional aspect ratio, along with friction and impacting mass on crashworthiness parameters such as specific energy absorption contact time, peak force and crush distance. The impact velocity is assumed to be constant at 15 m/s. The focus is on rectangular aluminium tubes and the analysis was carried out by using a validated finite element model. The analysis shows that the factors are not independent of each other and there is some degree of interaction between them. It was found that the trigger mechanism is a very important design factor to be included in the design of thin-walled tubes for energy absorption applications. The effect of the friction coefficient was found to be insignificant and finally, based on the interactions, it can be concluded that the most effective design would be a larger tube with small wall thickness, and a larger aspect ratio to avoid buckling.Universiti Tenaga Nasional, Malaysi

    Association of Higher Defensin β-4 Genomic Copy Numbers with Behçet’s Disease in Iraqi Patients

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    Objectives: Behçet’s disease (BD) is an immune-mediated small vessel systemic vasculitis. Human β-defensins are antimicrobial peptides associated with many inflammatory diseases and are encoded by the β-defensin family of multiple-copy genes. However, their role in BD necessitates further investigation. The aim of the present study was to investigate the possible association of BD in its various clinical forms with defensin β-4(DEFB4) genomic copy numbers. Methods: This case-control study was conducted from January to September 2011 and included 50 control subjects and 27 unrelated Iraqi BD patients registered at Baghdad Teaching Hospital, Bagdad, Iraq. Copy numbers of the DEFB4 gene were determined using the comparative cycle threshold method by duplex real-time polymerase chain reaction technology at the Department of Dermatology of Jena University Hospital, Jena, Germany. Results: DEFB4 genomic copy numbers were significantly higher in the BD group compared to the control group (P = 0.010). However, no statistically significant association was found between copy numbers and clinical variables within the BD group. Conclusion: The DEFB4 copy number polymorphism may be associated with BD; however, it is not associated with different clinical manifestations of the disease

    The Trail Pheromone of the Venomous Samsum Ant, Pachycondyla sennaarensis

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    Ant species use branching networks of pheromone trails for orientation between nest and resources. The current study demonstrated that workers of the venomous samsum ant, Pachycondyla sennaarensis (Mayr) (Hymenoptera: Formicidae: Ponerinae), employ recruitment trail pheromones discharged from the Dufour's gland. Secretions of other abdomen complex glands, as well as hindgut gland secretions, did not evoke trail following. The optimum concentration of trail pheromone was found to be 0.1 gland equivalent/40 cm trail. This concentration demonstrated effective longevity for about one hour. This study also showed that P. sennaarensis and Tapinoma simrothi each respond to the trail pheromones of the other species as well as their own

    Fintech and contactless payment: Help or hindrance? The role of invasion of privacy and information disclosure

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    Purpose: There is always a need to discover how a paradox between a customer’s desire for a more personalized experience and their privacy and security concerns would shape their intention to continue using contactless payment methods. However, personalization–privacy paradox has not been well-covered over the area of contactless payment. Therefore, this study aims to empirically examine the impact of personalization–privacy paradox on the customers’ continued intention (CIN) to use contactless payment. Design: /methodology/approach – The empirical part of the current study was conducted in Saudi Arabia by collecting the primary data using online questionnaire from a convenience sample size of 297 actual users of contactless payment methods. Findings: Based on structural equation modeling, personalization and privacy invasion were approved to significantly impact perceived value of information disclosure (PVD). Strong causal associations were confirmed between perceived severity, structural assurance and response cost with privacy invasion. Finally, both PVD and privacy invasion significantly predict CIN. : There are other important factors (i.e. technology interactivity, technology readiness, social influence, trust, prior experience, etc.) were not tested in the current study. Therefore, future studies would pay more attention regarding the impact of these factors. The current study data were also collected using a convenience sample of actual users of contactless payment methods. Therefore, there is a concern regarding the generalizability of the current study results to other kind of customers who have not used contactless payment. Originality/value: This study has integrated both personalization–privacy paradox and protection motivation theory in one model. The current study holds value in providing a new and complete picture of the inhibitors and enablers of customers’ CIN to use contactless payment, including new types of inhibitors. Furthermore, personalization–privacy paradox has not been fully examined over the related area of Fintech and contactless payment in general. Therefore, this study was able to extend the theoretical horizon personalization–privacy paradox to new area (i.e. contactless payment) and new cultural context (Saudi Arabia)

    Unifying linguistic annotations and ontologies for the Arabic Quran

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    The WACL’2 Second Workshop on Arabic Corpus Linguistics was held in conjunction with the Corpus Linguistics 2013 conference. Following on from the successful first WACL in 2011, as well as the related LRE-REL event in 2012, WACL-2 again took place at Lancaster University. The aim of this series of workshops is to create a venue for exploring progress in the field of research into the Arabic language using corpora, from across the many areas of corpus linguistics and computational linguistics where the analysis of Arabic structure and usage is an active issue. The scope of the workshop encompasses both (a) the design, construction and annotation of Arabic corpora, and (b) the use of corpora in research on the Arabic language – in any relevant area, including (but not limited to!) lexis and lexicography, syntax, collocation, NLP systems and analysis tools, contrastive and historical studies, stylistics, and discourse analysis. All varieties of Arabic – including the different Colloquial Arabics as well as Classical/Qur’anic and Modern Standard forms of the language – are within the workshop's purview

    The role of social networks in students’ learning experiences

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    The aim of this research is to investigate the role of social networks in computer science education. The Internet shows great potential for enhancing collaboration between people and the role of social software has become increasingly relevant in recent years. This research focuses on analyzing the role that social networks play in students’ learning experiences. The construction of students’ social networks, the evolution of these networks, and their effects on the students’ learning experience in a university environment are examined

    A Spotlight on the Egyptian Honeybee (Apis mellifera lamarckii)

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    Egypt has an ongoing long history with beekeeping, which started with the ancient Egyptians making various reliefs and inscriptions of beekeeping on their tombs and temples. The Egyptian honeybee (Apis mellifera lamarckii) is an authentic Egyptian honeybee subspecies utilized in apiculture. A. m. lamarckii is a distinct honeybee subspecies that has a particular body color, size, and high levels of hygienic behavior. Additionally, it has distinctive characteristics; including the presenceof the half-queens, an excessive number of swarm cells, high adaptability to climatic conditions, good resistance to specific bee diseases, including the Varro disorder, and continuous breeding during the whole year despite low productivity, using very little propolis, and tending to abscond readily. This review discusses the history of beekeeping in Egypt and its current situation in addition to its morphology, genetic analysis, and distinctive characters, and the defensive behaviors of native A. m.lamarckii subspecies.publishersversionPeer reviewe

    Is there a role for melatonin in fibromyalgia?

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    Fibromyalgia, characterised by persistent pain, fatigue, sleep disturbance and cognitive dysfunction, is a central sensitivity syndrome that also involves abnormality in peripheral generators and in the hypothalamic pituitary adrenal axis. Heterogeneity of clinical expression of fibromyalgia with a multifactorial aetiology has made the development of effective therapeutic strategies challenging. Physiological properties of the neurohormone melatonin appear related to the symptom profile exhibited by patients with fibromyalgia and thus disturbance of it’s production would be compatible with the pathophysiology. Altered levels of melatonin have been observed in patients with fibromyalgia which are associated with lower secretion during dark hours and higher secretion during daytime. However, inconsistencies of available clinical evidence limit conclusion of a relationship between levels of melatonin and symptom profiles in patients with fibromyalgia. Administration of melatonin to patients with fibromyalgia has demonstrated suppression of many symptoms and an improved quality of life consistent with benefit as a therapy for the management of this condition. Further studies with larger samples, however, are required to explore the potential role of melatonin in the pathophysiology of fibromyalgia and determine the optimal dosing regimen of melatonin for the management of fibromyalgia
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