237 research outputs found

    Study of Sun-Earth Couplings using MAGDAS/CPMN Data

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    第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月15日(火) 国立極地研究所 2階大会議

    Exploring the effect of simulated Motion Conditions on Task Performance

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    This thesis explored the effect that four different areas of motion conditioning presented in a motion simulator had on defence-force based task performance. It is produced in conjunction with the Defence Science and Technology Organisation, Land Operations Division, to expand their understanding of how these conditions may affect their personnel. The four conditions are explored are Motion Sickness, Motion Fatigue, Motion Perception and Mental Workload under motion conditions. All studies involved first year psychology students enrolled at the University of Sydney in accordance with the University’s ethical guidelines (2013/388). In the study of Motion Sickness, nausea was shown to have very little detrimental effect on task performance. In long term driving exposure there was a slight negative effect on the reaction time that was linked to motion sickness symptoms. Two styles of driving were researched for Motion Fatigue: boredom and constant motion. The boredom drive was seen to have a slightly negative effect on performance compared to the motion drive. In analysing biomarkers of fatigue relevant to a defence context, the best indicators were respiratory rate and the Root Mean Square of Successive Differences between normal heart beats. In Motion Perception, 6-axes of motion at 3 intensities were tested using Defence force tasks to determine whether any one axis, or a certain intensity, negatively affected performance more than others. Higher errors occurred in the Roll direction. The Pitch direction was the least comfortable for participants. In the final chapter of Mental Workload under motion, increased workload did not have a great impact on performance, although further studies are needed. In an analysis of subjective scales of workload in simple tasks, participants were able to accurately determine their task performance. From a bio-measure perspective, pupil diameter and respiratory rate were found to be the most indicative of changing levels of workload

    Analysis of Mineral and Heavy Metal Content of Some Commercial Fruit Juices by Inductively Coupled Plasma Mass Spectrometry

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    The presence of potentially toxic elements and compounds in foodstuffs is of intense public interest and thus requires rapid and accurate methods to determine the levels of these contaminants. Inductively coupled plasma mass spectrometry is a powerful tool for the determination of metals and nonmetals in fruit juices. In this study, 21 commercial fruit juices (apple, peach, apricot, orange, kiwi, pear, pineapple, and multifruit) present on Romanian market were investigated from the heavy metals and mineral content point of view by ICP-MS. Our obtained results were compared with those reported in literature and also with the maximum admissible limit in drinking water by USEPA and WHO. For Mn the obtained values exceeded the limits imposed by these international organizations. Co, Cu, Zn, As, and Cd concentrations were below the acceptable limit for drinking water for all samples while the concentrations of Ni and Pb exceeded the limits imposed by USEPA and WHO for some fruit juices. The results obtained in this study are comparable to those found in the literature.</jats:p

    Effects of Fe2O3 addition and annealing on the mechanical and dissolution properties of MgO- and CaO-containing phosphate glass fibres for bio-applications

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    This paper investigated the preparation of phosphate glass fibres (PGFs) in the following systems: i) 45P2O5-5B2O3-5Na2O-(29-x)CaO-16MgO-(x)Fe2O3and ii) 45P2O5-5B2O3-5Na2O-24CaO-(21-x)MgO-(x)Fe2O3(where x = 5, 8 and 11 mol%) for biomedical applications. Continuous fibres of 23 ± 1 μm diameter were prepared via a melt-draw spinning process. Compositions with higher Fe2O3content and higher MgO/CaO ratio required higher melting temperature and longer heating time to achieve glass melts for fibre pulling. The effects of Fe2O3 addition and annealing treatment on mechanical properties and degradation behaviours were also investigated. Adding Fe2O3 was found to increase the tensile strength from 523 ± 63 (Ca-Fe5) to 680 ± 75 MPa (Ca-Fe11), improve the tensile modulus from 72 ± 4 (Ca-Fe5) to 78 ± 3 GPa (Ca-Fe11) and decrease the degradation rate from 4.0 (Mg-Fe5) to 1.9 × 10-6kg m-2s-1(Mg-Fe11). The annealing process reduced the fibre tensile strength by 46% (Ca-Fe5), increased the modulus by 19.6% (Ca-Fe8) and decreased the degradation rate by 89.5% (Mg-Fe11) in comparison to the corresponding as-drawn fibres. Additionally, the annealing process also impeded the formation of precipitate shells and revealed coexistence of the precipitation and the pitting corrosion as fibre degradation behaviours

    Structural, thermal and dissolution properties of MgO- and CaO-containing borophosphate glasses: effect of Fe2O3 addition

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    This paper investigated manufacture of high-durability phosphate glass fibres for biomedical applications. Five different borophosphate glass formulations in the systems of 45P2O5–5B2O3–5Na2O–(29 − x)CaO–16MgO–(x)Fe2O3 and 45P2O5–5B2O3–5Na2O–24CaO–(21 − x)MgO–(x)Fe2O3 where x = 5, 8 and 11 mol% were produced via melt quenching. The compositions and amorphous nature of the glasses were confirmed by ICP-MS and XRD, respectively. FTIR results indicated depolymerisation of the phosphate chains with a decrease in Q2 units with increasing Fe2O3 content. DSC analyses showed an increase in Tg by ~5 °C with an increment of 3 mol% in Fe2O3 content. The thermal properties were also used to calculate processing window (i.e. Tc,ons—Tg) and another parameter, Kgl, to determine the suitability for fibre drawing directly from melt, which equals (Tc,ons—Tg)/(Tl—Tc,ons). The degradation study conducted in PBS solution at 37 °C showed a decrease of 25–47% in degradation rate with increasing Fe2O3 content. This confirmed that the chemical durability of the glasses had increased, which was suggested to be due to Fe2O3 addition. Furthermore, the density measured via Archimedes method revealed a linear increase with increasing Fe2O3 content

    Auditing in the Metaverse, the “New Reality”

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    The proposed study expresses some considerations about the digital transition in the accounting profession, especially its metaverse aspects. The main reason for this investigation is the importance of the topic in a world that is constantly changing. When reviewing the literature on this topic, the authors found several studies related to the role and importance of metaverse in the accounting profession. In their analysis, the authors conducted a qualitative study that focusses on the role and importance of the metaverse and its scope in the accounting profession. The results of the research show that although the digital transition is not at the beginning of the road, we must adapt to the new changes, so a professional accountant must also have significant knowledge in the field of IT. Following this study, the authors concluded that the role of the digital transition in the accounting profession is essential to face the new demands on the market and to respond in the shortest possible time to the demands of clients
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