Optimising temperature sensor placement for machine tool thermal error compensation

In this article, results of thermal error assessments are evaluated from a range of modern machine tools operating with active thermal compensation. The standard models assume a linear relationship between temperature and displacement and implementations address only a limited subset of error sources. However, significant residual errors were found on the analysed machines. The aim of this work is to improve the accuracy and increase the scope of compensated errors, without introducing onerous complexity, by using optimised linear correlation models applied to existing controllers

Extreme events and event size fluctuations in biased random walks on networks

Random walk on discrete lattice models is important to understand various types of transport processes. The extreme events, defined as exceedences of the flux of walkers above a prescribed threshold, have been studied recently in the context of complex networks. This was motivated by the occurrence of rare events such as traffic jams, floods, and power black-outs which take place on networks. In this work, we study extreme events in a generalized random walk model in which the walk is preferentially biased by the network topology. The walkers preferentially choose to hop toward the hubs or small degree nodes. In this setting, we show that extremely large fluctuations in event-sizes are possible on small degree nodes when the walkers are biased toward the hubs. In particular, we obtain the distribution of event-sizes on the network. Further, the probability for the occurrence of extreme events on any node in the network depends on its 'generalized strength', a measure of the ability of a node to attract walkers. The 'generalized strength' is a function of the degree of the node and that of its nearest neighbors. We obtain analytical and simulation results for the probability of occurrence of extreme events on the nodes of a network using a generalized random walk model. The result reveals that the nodes with a larger value of 'generalized strength', on average, display lower probability for the occurrence of extreme events compared to the nodes with lower values of 'generalized strength'

Environmental friendly method for the extraction of cellulose from Triflolium resopinatum and its characterization

The leaves of Triflolium resopinatum were collected from the mountains of Malakand division, Khyber Pukhtoonkhwa, Pakistan and was grinded into smaller particles and converted into powder. The ground biomass was treated with different solvents in the Soxhlet apparatus for the removal of soluble extractive like pectin, cutin and wax substances. For bond breaking the alkaline substance was kept in the autoclave. Ethylene diamine tetra-acetate (EDTA) and hydrogen peroxide (H2O2) were used for the removal of most polar substances like pectin, cutin, waxes and other extractives. Furthermore, raw cellulose was purified through acetic acid and nitric acid. Double distilled water was used for the neutralization of pH.The analysis of purified cellulose was carried out through different procedures such as X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The extracted cellulose has high degree of purity and crystallinity (72%) and thermal stability indicating that the process for the extraction of cellulose is quite adequate.               KEY WORDS: Triflolium resopinatum, Cellulose, FTIR, XRD, TGA, SEM Bull. Chem. Soc. Ethiop. 2019, 33(1), 61-68DOI: https://dx.doi.org/10.4314/bcse.v33i1.

Case Study On The Assessment Of Sinkhole Risk For The Development Of Infrastructure Over Karstic Ground

Practical Applications and Case Studie

Crafting a Systematic Literature Review on Open-Source Platforms

This working paper unveils the crafting of a systematic literature review on open-source platforms. The high-competitive mobile devices market, where several players such as Apple, Google, Nokia and Microsoft run a platforms- war with constant shifts in their technological strategies, is gaining increasing attention from scholars. It matters, then, to review previous literature on past platforms-wars, such as the ones from the PC and game-console industries, and assess its implications to the current mobile devices platforms-war. The paper starts by justifying the purpose and rationale behind this literature review on open-source platforms. The concepts of open-source software and computer-based platforms were then discussed both individually and in unison, in order to clarify the core-concept of 'open-source platform' that guides this literature review. The detailed design of the employed methodological strategy is then presented as the central part of this paper. The paper concludes with preliminary findings organizing previous literature on open-source platforms for the purpose of guiding future research in this area.Comment: As presented in 10th IFIP WG 2.13 International Conference on Open Source Systems, OSS 2014, San Jos\'e, Costa Rica, May 6-9, 201

Learning to breathe with Tai Chi online - qualitative data from a randomized controlled feasibility study of patients with cystic fibrosis

Introduction Tai Chi (TC), a gentle exercise, incorporates meditative movement and respiratory control. The high risk of cross infection for people with cystic fibrosis (CF) requires close management in healthcare settings, limiting group activities such as TC. A mixed-methods randomized controlled feasibility study compared teaching TC over the internet with in-person, face to face TC tuition provided to CF patients. This article explores qualitative data from patients and TC instructors on their attitudes, acceptability and engagement with the two modes of TC delivery. Methods Qualitative data from CF patients (>6 years) were collected using Skype interviews/focus groups and written feedback. TC instructors provided weekly written feedback, and took part in interviews/ focus groups at the end of the study. Patient and instructor interviews explored their experiences and engagement with TC online delivery and ability to practice. Results Irrespective of the type of TC delivery, all CF participants interviewed (n = 28) practiced between lessons and most wanted to continue TC. Teenagers were more likely to miss TC appointments. Internet delivery was well received by both patients and TC instructors. Two patients reported difficulties with screen size/camera and one with internet connectivity. Conclusion Both face-to-face and internet delivery of TC lessons were equally well received and perceived as beneficial. In the current COVID-19 pandemic, CF patients self-isolating could find this intervention provides important support, therefore the programme was made available on YouTube in April 2020 and linked to the websites of the CF charities funding the research