Observations of red-giant variable stars by Aboriginal Australians

Aboriginal Australians carefully observe the properties and positions of stars, including both overt and subtle changes in their brightness, for subsistence and social application. These observations are encoded in oral tradition. I examine two Aboriginal oral traditions from South Australia that describe the periodic changing brightness in three pulsating, red-giant variable stars: Betelgeuse (Alpha Orionis), Aldebaran (Alpha Tauri), and Antares (Alpha Scorpii). The Australian Aboriginal accounts stand as the only known descriptions of pulsating variable stars in any Indigenous oral tradition in the world. Researchers examining these oral traditions over the last century, including anthropologists and astronomers, missed the description of these stars as being variable in nature as the ethnographic record contained several misidentifications of stars and celestial objects. Arguably, ethnographers working on Indigenous Knowledge Systems should have academic training in both the natural and social sciences.Comment: The Australian Journal of Anthropology (2018

The first high-amplitude delta Scuti star in an eclipsing binary system

We report the discovery of the first high-amplitude delta Scuti star in an eclipsing binary, which we have designated UNSW-V-500. The system is an Algol-type semi-detached eclipsing binary of maximum brightness V = 12.52 mag. A best-fitting solution to the binary light curve and two radial velocity curves is derived using the Wilson-Devinney code. We identify a late A spectral type primary component of mass 1.49+/-0.02 M_sun and a late K spectral type secondary of mass 0.33+/-0.02 M_sun, with an inclination of 86.5+/-1.0 degrees, and a period of 5.3504751+/-0.0000006 d. A Fourier analysis of the residuals from this solution is performed using PERIOD04 to investigate the delta Scuti pulsations. We detect a single pulsation frequency of f_1 = 13.621+/-0.015 c/d, and it appears this is the first overtone radial mode frequency. This system provides the first opportunity to measure the dynamical mass for a star of this variable type; previously, masses have been derived from stellar evolution and pulsation models.Comment: 7 pages, 6 figures, 2 tables, for submission to MNRAS, v2: paper size change, small typographical changes to abstrac

Combined Heat and Power From Low Temperature Heat: HFO-1336mzz(Z) as a Working Fluid for Organic Rankine Cycles

Increasing awareness of the environmental impacts associated with the extraction and combustion of fossil fuels and the continued uncertainty of fossil fuel supplies and prices are motivating a renewed interest in the utilization of abundantly available low temperature heat (e.g. waste heat from industrial or commercial processes, mobile or stationary internal combustion engines, geothermal heat, etc.). Conversion of heat to mechanical (or electrical) power through Organic Rankine Cycles (ORCs) and elevation of the temperature of available heat through High Temperature Heat Pumps (HTHPs) to meet heating requirements are two promising approaches. They both require the use of working fluids.  The emerging availability of HFO-1336mzz(Z) (cis-CF3CH=CHCF3), with a GWP sufficiently low so as to virtually eliminate business risk from increasingly restrictive climate protection regulations around the globe and with performance sufficiently high so as to minimize payback time is now motivating substantial ORC and HTHP research and development investments. This paper will examine the potential of emerging ORC and HTHP technologies using HFO-1336mzz(Z) as the working fluid to provide power and heating from low temperature heat with reduced cost and environmental impact. HFO-1336mzz(Z) new and previously published chemical, thermodynamic, safety, health and environmental properties will be reviewed and predicted and measured performance will be reported.  HFO-1336mzz(Z) is currently under laboratory and field testing for various targeted applications.  It is on a path to full-scale commercial production in 2017

The HERA-B Ring Imaging Cherenkov Counter

The HERA-B RICH uses a radiation path length of 2.8 m in C_4F_10 gas and a large 24 square meters spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27000 channels. A 2:1 reducing two-lens telescope in front of each PMT increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the RICH was fully reached: the average number of detected photons in the RICH for a beta=1 particle was found to be 33 with a single hit resolution of 0.7 mrad and 1 mrad in the fine and coarse granularity regions, respectively.Comment: 29 pages, 23 figure

Bounds on the Complexity of Halfspace Intersections when the Bounded Faces have Small Dimension

We study the combinatorial complexity of D-dimensional polyhedra defined as the intersection of n halfspaces, with the property that the highest dimension of any bounded face is much smaller than D. We show that, if d is the maximum dimension of a bounded face, then the number of vertices of the polyhedron is O(n^d) and the total number of bounded faces of the polyhedron is O(n^d^2). For inputs in general position the number of bounded faces is O(n^d). For any fixed d, we show how to compute the set of all vertices, how to determine the maximum dimension of a bounded face of the polyhedron, and how to compute the set of bounded faces in polynomial time, by solving a polynomial number of linear programs

Pedestrian, Crowd, and Evacuation Dynamics

This contribution describes efforts to model the behavior of individual pedestrians and their interactions in crowds, which generate certain kinds of self-organized patterns of motion. Moreover, this article focusses on the dynamics of crowds in panic or evacuation situations, methods to optimize building designs for egress, and factors potentially causing the breakdown of orderly motion.Comment: This is a review paper. For related work see http://www.soms.ethz.c

Design and rationale of FINE-REAL: A prospective study of finerenone in clinical practice

AIMS: Contemporary patterns of care of patients with chronic kidney disease (CKD) associated with type 2 diabetes (T2D) and the adoption of finerenone are not known. The FINE-REAL study (NCT05348733) is a prospective observational study in patients with CKD and T2D to provide insights into the use of the nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone in clinical practice. METHODS: FINE-REAL is an international, prospective, multicenter, single-arm study enrolling approximately 5500 adults with CKD and T2D in an estimated 200 sites across 22 countries. The study is anticipated to be ongoing until 2027. RESULTS: The primary objective is to describe treatment patterns in patients with CKD and T2D treated with finerenone in routine clinical practice. Secondary objectives include assessment of safety with finerenone. Other endpoints include characterization of healthcare resource utilization and occurrence of newly diagnosed diabetic retinopathy or its progression from baseline in patients with existing disease. A biobank is being organized for future explorative analyses with inclusion of participants from the United States. CONCLUSIONS: FINE-REAL is the first prospective observational study with a nonsteroidal MRA in a population with CKD and T2D and is expected to provide meaningful insights into the treatment of CKD associated with T2D. FINE-REAL will inform decision-making with respect to initiation of finerenone in patients with CKD and T2D

The continuous stop location problem in public transportation networks

In this paper we consider the location of stops along the edges of an already existing public transportation network. This can be the introduction of bus stops along some given bus routes, or of railway stations along the tracks in a railway network. The positive effect of new stops is given by the better access of the potential customers to their closest station, while the increasement of travel time caused by the additional stopping activities of the trains leads to a negative effect. The goal is to cover all given demand points with a minimal amount of additional traveling time, where covering may be defined with respect to an arbitrary norm (or even a gauge). Unfortunately, this problem is NP-hard, even if only the Euclidean distance is used. In this paper, we give a reduction to a finite candidate set leading to a discrete set covering problem. Moreover, we identify network structures in which the coefficient matrix of the resulting set covering problem is totally unimodular, and use this result to derive efficient solution approaches. Various extensions of the problem are also discussed