Red Optical Planet Survey : A radial velocity search for low mass M dwarf planets

This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedWe present radial velocity results from our Red Optical Planet Survey (ROPS), aimed at detecting low-mass planets orbiting mid-late M dwarfs. The similar to 10 ms(-1) precision achieved over 2 consecutive nights with the MIKE spectrograph at Magellan Clay is also found on week long timescales with UVES at VLT. Since we find that UVES is expected to attain photon limited precision of order 2 ms-1 using our novel deconvolution technique, we are limited only by the

Association between pelvic inflammatory disease, infertility, ectopic pregnancy and the development of ovarian serous borderline tumor, mucinous borderline tumor and low-grade serous carcinoma

Objective: Risk factors for ovarian borderline tumors and low-grade serous carcinoma (LGSC) are poorly understood. The aim of this study was to examine the association between infertility, pelvic inflammatory disease (PID), endometriosis, ectopic pregnancy, hysterectomy, tubal ligation and parity and the risk of serous borderline tumor (SBT), mucinous borderline tumor (MBT) and LGSC. Methods: This was a population-based cohort study using linked administrative and hospital data. Participants were 441,382 women born between 1945 and 1975 who had been admitted to hospital in Western Australia between 1 January 1980 and 30 June 2014. We used Cox regression to estimate hazard ratios (HRs). Results: We observed an increased rate of SBT associated with infertility, PID and ectopic pregnancy (HRs and 95% CIs were, respectively, 1.98 (1.20–3.26); 1.95 (1.22–3.10) and 2.44 (1.20–4.96)). We did not detect an association between any of the factors under study and the rate of MBT. A diagnosis of PID was associated with an increased rate of LGSC (HR 2.90, 95% CI 1.21–6.94). Conclusions: The association with PID supports the hypothesis that inflammatory processes within the upper gynaecological tract and/or peritoneum may predispose to the development of SBT and LGSC

Intermittent structural weakening and acceleration of the Thwaites Glacier Tongue between 2000 and 2018

Evolving conditions at the terminus of Thwaites Glacier will be important in determining the rate of its future sea-level contribution over the coming decades. Here, we use remote-sensing observations to investigate recent changes (2000–2018) in the structure and velocity of Thwaites Glacier and its floating tongue. We show that the main trunk of Thwaites Glacier has accelerated by 38% over this period, while its previously intact floating tongue has transitioned to a weaker mélange of fractured icebergs bounded by sea ice. However, the rate of structural weakening and acceleration was not uniform across the observational period and we identify two periods of rapid acceleration and structural weakening (2006–2012; 2016–2018), separated by a period of deceleration and re-advance of the structurally-intact shear margin boundary (2012–2015). The timing of these accelerations/decelerations strongly suggests a link to variable ocean forcing. The weakened tongue now has some dependency on landfast sea ice for structural integrity and is vulnerable to changes in landfast ice persistency. Future reductions in landfast sea ice could manifest from changes in climate and/or the imminent removal of the B-22A iceberg from the Thwaites embayment. Such changes could have important implications for the integrity of the ice tongue and future glacier discharge

Maglev six degree-of-freedom fine position stage control system

A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL). The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development experience. System enhancements, implemented on a second generation design for a National Center for Advanced Information Component Manufacturing (NCAICM) Structural Control Testbed, define the present level of research. This paper describes the design, implementation, and functional capability of the systems. Specifics regarding control system electronics, including software and control algorithm structure, as well as performance design goals and test results are presented

Positioning performance of a maglev fine positioning system

A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL) research tool. The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development experience. System enhancements, implemented on a second generation design for an ARPA National Center for Advanced Information Component Manufacturing (NCAICM) project, introduced active structural control for the levitated structure of the system. Magnetic levitation (maglev) is emerging as an important technology for wafer positioning systems in advanced lithography applications. The advantages of maglev stem from the absence of physical contact. The resulting lack of friction enables accurate, fast positioning. Maglev systems are mechanically simple, accomplishing full six degree-of-freedom suspension and control with a minimum of moving parts. Power-efficient designs, which reduce the possibility of thermal distortion of the platen, are achievable. Manufacturing throughput will be improved in future systems with the addition of active structural control of the positioning stages. This paper describes the design, implementation, and functional capability of the maglev fine positioning system. Specifics regarding performance design goals and test results are presented

Induction motor performance testing with an inverter power supply, part 1

The development of high-power density electrical machines continues to accelerate, driven by military, transportation, and industrial needs to achieve more power in a smaller package. Higher speed electrical machines are a recognized path toward achieving higher power densities. Existing industry testing standards describe well-defined procedures for characterizing both synchronous and induction machines. However, these procedures are applicable primarily to fixed-frequency (usually 60 or 50 Hz) power supplies. As machine speeds increase well beyond the 3600-rpm limitation of 60-Hz machines, a need for performance testing at higher frequencies is emerging. An inverter power supply was used to conduct a complete series of tests on two induction motors (0.5 and 1.0 MW) with speeds up to ~5000 rpm. The use of a nonsinusoidal power supply with limited power output capability required the development of measurement techniques and testing strategies quite different than those typically used for 60/50 Hz testing. Instrumentation and techniques for measuring voltage, current, and power on harmonic rich waveforms with accuracies approaching 1% are described. Locked-rotor and breakdown torque tests typically require large kVA input to the motor, much higher than the rated load requirement. An inverter sized for the rated load requirements of the motor was adapted to perform locked-rotor and breakdown torque tests. Inverter drive protection features, such as anti-hunting and current limit that were built into the inverter had to be factored into the test planning and implementation. Test results are presented in two companion papers. This paper (Part 1) correlates test results with the results of an algorithmic induction motor analysis program. Part 2 presents the test results compared with a Matlab simulation program and also provides a comprehensive discussion of the instrumentation that was essential to achieve testing accuracy. Correlating test results with calculated valu- es confirmed that the testing techniques developed during this testing program are useful for evaluating high-speed, high-power density electrical machineryCenter for Electromechanic

Large-eddy simulation of the lid-driven cubic cavity flow by the spectral element method

This paper presents the large-eddy simulation of the lid-driven cubic cavity flow by the spectral element method (SEM) using the dynamic model. Two spectral filtering techniques suitable for these simulations have been implemented. Numerical results for Reynolds number $\text{Re}=12'000$ are showing very good agreement with other experimental and DNS results found in the literature

STATIONARY SOLUTIONS IN BRANS-DICKE STOCHASTIC INFLATIONARY COSMOLOGY

In Brans-Dicke theory the Universe becomes divided after inflation into many exponentially large domains with different values of the effective gravitational constant. Such a process can be described by diffusion equations for the probability of finding a certain value of the inflaton and dilaton fields in a physical volume of the Universe. For a typical chaotic inflation potential, the solutions for the probability distribution never become stationary but grow forever towards larger values of the fields. We show here that a non-minimal conformal coupling of the inflaton to the curvature scalar, as well as radiative corrections to the effective potential, may provide a dynamical cutoff and generate stationary solutions. We also analyze the possibility of large nonperturbative jumps of the fluctuating inflaton scalar field, which was recently revealed in the context of the Einstein theory. We find that in the Brans--Dicke theory the amplitude of such jumps is strongly suppressed.Comment: 19 pages, LaTe

Is there a Jordan geometry underlying quantum physics?

There have been several propositions for a geometric and essentially non-linear formulation of quantum mechanics. From a purely mathematical point of view, the point of view of Jordan algebra theory might give new strength to such approaches: there is a ``Jordan geometry'' belonging to the Jordan part of the algebra of observables, in the same way as Lie groups belong to the Lie part. Both the Lie geometry and the Jordan geometry are well-adapted to describe certain features of quantum theory. We concentrate here on the mathematical description of the Jordan geometry and raise some questions concerning possible relations with foundational issues of quantum theory.Comment: 30 page