On the Recognition of Fan-Planar and Maximal Outer-Fan-Planar Graphs

Fan-planar graphs were recently introduced as a generalization of 1-planar graphs. A graph is fan-planar if it can be embedded in the plane, such that each edge that is crossed more than once, is crossed by a bundle of two or more edges incident to a common vertex. A graph is outer-fan-planar if it has a fan-planar embedding in which every vertex is on the outer face. If, in addition, the insertion of an edge destroys its outer-fan-planarity, then it is maximal outer-fan-planar. In this paper, we present a polynomial-time algorithm to test whether a given graph is maximal outer-fan-planar. The algorithm can also be employed to produce an outer-fan-planar embedding, if one exists. On the negative side, we show that testing fan-planarity of a graph is NP-hard, for the case where the rotation system (i.e., the cyclic order of the edges around each vertex) is given

Systematic study of the decay rates of antiprotonic helium states

A systematic study of the decay rates of antiprotonic helium (\pbhef and \pbhet) at CERN AD (Antiproton Decelerator) has been made by a laser spectroscopic method. The decay rates of some of its short-lived states, namely those for which the Auger rates $\gamma_{\mathrm{A}}$ are much larger than their radiative decay rates ($\gamma_{\mathrm{rad}} \sim 1$ $\mu$s$^{-1}$), were determined from the time distributions of the antiproton annihilation signals induced by laser beams, and the widths of the atomic resonance lines. The magnitude of the decay rates, especially their relation with the transition multipolarity, is discussed and compared with theoretical calculations.Comment: 6 pages, 5 figures, and 1 tabl

Using Sifting for k-Layer Straightline Crossing Minimization

We present a new algorithm for k-layer straightline crossing minimization which is based on sifting that is a heuristic for dynamic reordering of decision diagrams used during logic synthesis and formal verification of logic circuits. The experiments prove sifting to be very efficient. In particular it outperforms the traditional layer by layer sweep based heuristics known from literature by far when applied to k-layered graphs with k \ge 3

Bar 1-Visibility Drawings of 1-Planar Graphs

A bar 1-visibility drawing of a graph $G$ is a drawing of $G$ where each vertex is drawn as a horizontal line segment called a bar, each edge is drawn as a vertical line segment where the vertical line segment representing an edge must connect the horizontal line segments representing the end vertices and a vertical line segment corresponding to an edge intersects at most one bar which is not an end point of the edge. A graph $G$ is bar 1-visible if $G$ has a bar 1-visibility drawing. A graph $G$ is 1-planar if $G$ has a drawing in a 2-dimensional plane such that an edge crosses at most one other edge. In this paper we give linear-time algorithms to find bar 1-visibility drawings of diagonal grid graphs and maximal outer 1-planar graphs. We also show that recursive quadrangle 1-planar graphs and pseudo double wheel 1-planar graphs are bar 1-visible graphs.Comment: 15 pages, 9 figure

Explosive Dust Test Vessel Comparison using Pulverized Pittsburgh Coal

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and subsequent fires caused by coal dust can result in significant property damage, loss of life in underground coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted research on coal dust explosions until 1996 when it was dissolved. In the following years, the American Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard test method characterizing the “explosibility” of particulate solids of combustible materials suspended in air. The research presented herein investigates the explosive characteristic of Pulverized Pittsburgh Coal dust using the ASTM E1226-12 test standard. The explosibility characteristics include: maximum explosion pressure, (Pmax); maximum rate of pressure rise, (dP/dt)max; and explosibility index, (Kst). Nine Pulverized Pittsburgh Coal dust concentrations, ranging from 30 to 1,500 g/m3 , were tested in a 20-Liter Siwek Sphere. The newly recorded dust explosibility characteristics are then compared to explosibility characteristics published by the Bureau of Mines in their 20 liter vessel and procedure predating ASTM E1126-12. The information presented in this paper will allow for structures and devices to be built to protect people from the effects of coal dust explosions

Hyperfine structure of antiprotonic helium revealed by a laser-microwave-laser resonance method

Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the $(n,L)=(37,35)$ state of antiprotonic helium. This experiment confirms the quadruplet hyperfine structure due to the interaction of the antiproton orbital angular momentum, the electron spin and the antiproton spin as predicted by Bakalov and Korobov. The measured frequencies of $\nu_{\text HF}^+ =12.89596 \pm 0.00034$ GHz and $\nu_{\text HF}^- =12.92467 \pm 0.00029$ GHz agree with recent theoretical calculations on a level of $6 \times10^{-5}$.Comment: 4 pages, 4 figures, 1 tabl

“Cultural security is an on-going journey…” Exploring views from staff members on the quality and cultural security of services for Aboriginal families in Western Australia

Cultural security is a key element of accessible services for Indigenous peoples globally, although few studies have examined this empirically. We explored the scope, reach, quality, and cultural security of health and social services available to Aboriginal and/or Torres Strait Islander families in Western Australia (WA), from the point of view of staff from the services. We recruited staff from health and social services for Aboriginal people in the Perth, Kalgoorlie, Great Southern, and South West regions of WA between December 2015 and September 2017 to complete online surveys. We examined the proportions of participants that responded saying the service was culturally secure, the reasons for the response, and perceived factors related to a high-quality service. Sixty participants from 21 services responded to the survey. Seventy-three percent stated the service was culturally secure; however, only 36% stated that the staff employed at the service had sufficient knowledge on cultural security. Participants suggested having Aboriginal staff and better cultural awareness training as methods to improve cultural security within the service. Participants highlighted that staffing, funding for resources, and patient financial difficulties in accessing care as key areas for quality improvement. Much greater effort is required in improving knowledge through on-going training of staff in the practice of culturally safe care. Organisations must also be required to meet specific standards in cultural safety

New insights into the association of air pollution and kidney diseases by tracing gold nanoparticles with inductively coupled plasma mass spectrometry

Exposure to particles in air pollution has been associated with kidney disease, however, the underlying biological mechanisms are incompletely understood. Inhaled particles can gain access to the circulation and, depending on their size, pass into urine, raising the possibility that particles may also sequester in the kidney and directly alter renal function. This study optimised an inductively coupled plasma mass spectrometry (ICP-MS) method to investigate the size dependency of particle accumulation in the kidney in mice following pulmonary instillation (0.8 mg in total over 4 weeks) to gold nanoparticles (2, 3-4, 7-8, 14 or 40 nm, or saline control). Due to the smallest particle sizes being below the limit of detection in single particle mode, ICP-MS was operated in the total quantification mode. Gold was detected in all matrices of interest (blood, urine and kidney) from animals treated with all sizes of gold nanoparticles, at orders of magnitude higher than the methodological limit of detection in biological matrices (0.013 ng/mL). A size-dependent effect was observed, with smaller particles leading to greater levels of accumulation in tissues. This study highlights the value of a robust and reliable method by ICP-MS to detect extremely low levels of gold in biological samples for indirect particle tracing. The finding that nano-sized particles translocate from the lung to the kidney may provide a biological explanation for the associations between air pollution and kidney disease