Effect of alloying elements on magnesium alloy damping capacities at room temperature

Alloying is a good approach to increasing its strength but leads to a reduction of damping to pure magnesium. Classifying the alloying characteristics of various alloying elements in magnesium alloys and their combined effects on the damping and mechanical properties of magnesium alloys is important. In this paper, the properties of the Mg-0.6wt%X binary alloys were analyzed through strength measurements and dynamic mechanical analysis. The effects of foreign atoms on solid-solution strengthening and dislocation damping were studied comprehensively. The effect of solid solubility on damping capacity can be considered from two perspectives: the effect of single solid-solution atoms on the damping capacities of the alloy, and the effect of solubility on the damping capacities of the alloy. The results provide significant information that is useful in developing high-strength, high-damping magnesium alloys. This study will provide scientific guidance regarding the development of new types of damping magnesium alloys

Microbial modulation in the biomass and toxin production of a red-tide causing alga

The effect of S10, a strain of marine bacteria isolated from sediment in the Western Xiamen Sea, on the growth and paralytic shellfish poison (PSP) production in the alga Alexandrium tamarense (A. tamarense) was studied under controlled experimental conditions.The results of these experiments have shown that the growth of A. tamarense is obviously inhibited by S10 at high concentrations,however no evident effect on its growth was observed at low concentrations. Its PSP production was also inhibited by S10 at different concentrations, especially at low concentrations. The toxicity of this strain of A. tamarense is about (0.95– 12.14) • 10－6 MU/cell, a peak toxicity value of 12.14 • 10－6 MU/cell appeared on the 14th day, after which levels decreased gradually.The alga grew well in conditions of pH 6–8 and salinities of 20–34‰. The toxicity of the alga varied markedly at different pH and salinity levels. Toxicity decreased as pH increased, while it increased with salinity and reached a peak value at a salinity of 30‰,after which it declined gradually. S10 at a concentration of 1.02 • 109 cells/ml inhibited growth and the PSP production of A. tamarense at different pH and salinity levels. S10 had the strongest inhibitory function on the growth of A. tamarense under conditions of pH 7 and a salinity of 34‰. The best inhibitory effect on PSP production by A. tamarense was at pH 7, this inhibitory effect on PSP production did not relate to salinity. Interactions between marine bacteria and A. tamarense were also investigated using the flow cytometer technique (FCM) as well as direct microscope counting. S10 was identified as being a member of the genus Bacillus, the difference in 16S rDNA between S10 and Bacillus halmapalus was only 2%. The mechanism involved in the inhibition of growth and PSP production of A. tamarense by this strain of marine bacteria, and the prospect of using it and other marine bacteria in the biocontrol of red-tides was discussed

A polarized beam splitter using an anisotropic medium slab

The propagation of electromagnetic waves in the anisotropic medium with a single-sheeted hyperboloid dispersion relation is investigated. It is found that in such an anisotropic medium E- and H-polarized waves have the same dispersion relation, while E- and H-polarized waves exhibit opposite amphoteric refraction characteristics. E- (or H-) polarized waves are positively refracted whereas H- (or E-) polarized waves are negatively refracted at the interface associated with the anisotropic medium. By suitably using the properties of anomalous refraction in the anisotropic medium it is possible to realize a very simple and very efficient beam splitter to route the light. It is shown that the splitting angle and the splitting distance between E- and H- polarized beam is the function of anisotropic parameters, incident angle and slab thickness.Comment: 14 pages, 6 figure

Sixty Years of Fractal Projections

Sixty years ago, John Marstrand published a paper which, among other things, relates the Hausdorff dimension of a plane set to the dimensions of its orthogonal projections onto lines. For many years, the paper attracted very little attention. However, over the past 30 years, Marstrand's projection theorems have become the prototype for many results in fractal geometry with numerous variants and applications and they continue to motivate leading research.Comment: Submitted to proceedings of Fractals and Stochastics

The Vacuum System of HIRFL

AbstractThe vacuum system of Heavy Ion Research Facility in Lanzhou (HIRFL) is a large and complex system. HIRFL consists of two ECR ion sources, a sector focus cyclotron (SFC), a separate sector cyclotron (SSC) and a multi-purpose cooling storage ring system which has a main ring (CSRm) and an experiment ring (CSRe). Several beam lines connect these accelerators together and transfer various heavy ion beams to more than 10 experiment terminals. According to the requirements of the ion acceleration and ion lifetime, the working pressure in each accelerator is different. SFC is nearly 50 years old. After upgrade, the working pressure in SFC is improved from 10-6mbar to 10-8mbar. The pressure in SSC which was built in the 1980s reaches the same level. The cooling storage ring system with a length of 500m came into operation in 2007. The average pressures in CSRm and CSRe are 5×10-12mbar and 8×10-12mbar respectively. Different designs were adopt for vacuum system of a dozen beam lines to meet specific requirement of each experiment terminal. Along with the extensive development of the heavy ion researches and applications, new accelerators of HIRFL are under construction. The vacuum system of the new machines will be designed and constructed followed the overall schedule

Weak lensing, dark matter and dark energy

Weak gravitational lensing is rapidly becoming one of the principal probes of dark matter and dark energy in the universe. In this brief review we outline how weak lensing helps determine the structure of dark matter halos, measure the expansion rate of the universe, and distinguish between modified gravity and dark energy explanations for the acceleration of the universe. We also discuss requirements on the control of systematic errors so that the systematics do not appreciably degrade the power of weak lensing as a cosmological probe.Comment: Invited review article for the GRG special issue on gravitational lensing (P. Jetzer, Y. Mellier and V. Perlick Eds.). V3: subsection on three-point function and some references added. Matches the published versio

Wireless transmission of biosignals for hyperbaric chamber applications

[EN] This paper presents a wireless system to send biosignals outside a hyperbaric chamber avoiding wires going through the chamber walls. Hyperbaric chambers are becoming more and more common due to new indications of hyperbaric oxygen treatments. Metallic walls physically isolate patients inside the chamber, where getting a patient's vital signs turns into a painstaking task. The paper proposes using a ZigBee-based network to wirelessly transmit the patient's biosignals to the outside of the chamber. In particular, a wearable battery supported device has been designed, implemented and tested. Although the implementation has been conducted to transmit the electrocardiography signal, the device can be easily adapted to consider other biosignals.The authors would like to thanks the University of Balearic Islands (UIB), the Miguel Hernandez University (UMH), MEDIBAROX unit of the Perpetuo Socorro Hospital and the "Catedra de Medicina Hiperbarica" (UMH) for their support allowing the use of its facilities for this work. The authors would also like to thank Borja Mas Boned for his help designing the LabVIEW application. This research has been carried out with funding and promotion of "Catedra de Medicina Hiperbarica" of the Miguel Hernandez University. http://nbio.umh.es/es/2010/12/01/catedra-de-medicina-hiperbarica-medibarox/.Perez-Vidal, C.; Gracia Calandin, LI.; Carmona, C.; Alorda, B.; Salinas, A. (2017). Wireless transmission of biosignals for hyperbaric chamber applications. PLoS ONE. 12(3):1-19. https://doi.org/10.1371/journal.pone.0172768S119123Sureda, A., Batle, J. M., Martorell, M., Capó, X., Tejada, S., Tur, J. A., & Pons, A. (2016). Antioxidant Response of Chronic Wounds to Hyperbaric Oxygen Therapy. PLOS ONE, 11(9), e0163371. doi:10.1371/journal.pone.0163371Branco, B. H. M., Fukuda, D. H., Andreato, L. V., Santos, J. F. da S., Esteves, J. V. D. C., & Franchini, E. (2016). The Effects of Hyperbaric Oxygen Therapy on Post-Training Recovery in Jiu-Jitsu Athletes. PLOS ONE, 11(3), e0150517. doi:10.1371/journal.pone.0150517Xu, Y., Ji, R., Wei, R., Yin, B., He, F., & Luo, B. (2016). The Efficacy of Hyperbaric Oxygen Therapy on Middle Cerebral Artery Occlusion in Animal Studies: A Meta-Analysis. PLOS ONE, 11(2), e0148324. doi:10.1371/journal.pone.0148324Lin, B.-S., Lin, B.-S., Chou, N.-K., Chong, F.-C., & Chen, S.-J. (2006). RTWPMS: A Real-Time Wireless Physiological Monitoring System. IEEE Transactions on Information Technology in Biomedicine, 10(4), 647-656. doi:10.1109/titb.2006.874194Hu, S., Wei, H., Chen, Y., & Tan, J. (2012). A Real-Time Cardiac Arrhythmia Classification System with Wearable Sensor Networks. Sensors, 12(9), 12844-12869. doi:10.3390/s120912844Burns, A., Greene, B. R., McGrath, M. J., O’Shea, T. J., Kuris, B., Ayer, S. M., … Cionca, V. (2010). SHIMMER™ – A Wireless Sensor Platform for Noninvasive Biomedical Research. IEEE Sensors Journal, 10(9), 1527-1534. doi:10.1109/jsen.2010.2045498Gil, Y., Wu, W., & Lee, J. (2012). A Synchronous Multi-Body Sensor Platform in a Wireless Body Sensor Network: Design and Implementation. Sensors, 12(8), 10381-10394. doi:10.3390/s120810381Chin-Teng Lin, Kuan-Cheng Chang, Chun-Ling Lin, Chia-Cheng Chiang, Shao-Wei Lu, Shih-Sheng Chang, … Li-Wei Ko. (2010). An Intelligent Telecardiology System Using a Wearable and Wireless ECG to Detect Atrial Fibrillation. IEEE Transactions on Information Technology in Biomedicine, 14(3), 726-733. doi:10.1109/titb.2010.2047401W. Y. Chung, Y. D. Lee, and S. J. Jung, 'A Wireless Sensor Network Compatible Wearable U-Healthcare Monitoring System Using Integrated Ecg, Accelerometer and Spo2', Conf Proc IEEE Eng Med Biol Soc, 2008 (2008), 1529–32.ZigBee Alliance; http://www.zigbee.org/Mahmood, A., Javaid, N., & Razzaq, S. (2015). A review of wireless communications for smart grid. Renewable and Sustainable Energy Reviews, 41, 248-260. doi:10.1016/j.rser.2014.08.036J.S. Lee, Y.W. Su, and C.C. Shen, "A comparative study of wireless protocols: Bluetooth, UWB, ZigBee, and Wi-Fi, 33rd Annual Conference of the IEEE Industrial Electronics Society (IECON), 2007, pp. 46–51.P.P. Parikh, M.G. Kanabar, and T.S. Sidhu, "Opportunities and challenges of wireless communication technologies for smart grid applications, IEEE PES General Meeting, 2010, pp. 1–7.Fadlullah, Z. M., Fouda, M. M., Kato, N., Takeuchi, A., Iwasaki, N., & Nozaki, Y. (2011). Toward intelligent machine-to-machine communications in smart grid. IEEE Communications Magazine, 49(4), 60-65. doi:10.1109/mcom.2011.5741147A.C. Olteanu, G.D. Oprina, N. Tapus, and S. Zeisberg, "Enabling mobile devices for home automation using ZigBee, 19th IEEE International Conference on Control Systems and Computer Science, 2013, pp. 189–195.Shang, Y. (2014). Vulnerability of networks: Fractional percolation on random graphs. Physical Review E, 89(1). doi:10.1103/physreve.89.012813R. Barea-Navarro. Biomedical Instrumentation. Chapter 3. University of Alcala

Measurement of W Polarisation at LEP

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

Search for Anomalous Couplings in the Higgs Sector at LEP

Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

Measurement of W Polarisation at LEP

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation