The Light Curve and Internal Magnetic Field of the Mode-Switching Pulsar PSR B0943+10

A number of radio pulsars exhibit intriguing mode-switching behavior. Recent observations of PSR B0943+10 revealed correlated radio and X-ray mode switches, providing a new avenue for understanding this class of objects. The large X-ray pulse fraction observed during the radio quiet phase (Q mode) was previously interpreted as a result of changing obscuration of X-rays by dense magnetosphere plasma. We show that the large X-ray pulse fraction can be explained by including the beaming effect of a magnetic atmosphere, while remaining consistent with the dipole field geometry constrained by radio observations. We also explore a more extreme magnetic field configuration, where a magnetic dipole displaced from the center of the star produces two magnetic polar caps of different sizes and magnetic field strengths. These models are currently consistent with data in radio and X-rays and can be tested or constrained by future X-ray observations.Comment: 5 pages, 5 figures, submitted to ApJ

The magnetic field in the NGC 2024 FIR 5 dense core

We used the Submillimeter Array (SMA) to observe the thermal polarized dust emission from the protostellar source NGC 2024 FIR 5. The polarized emission outlines a partial hourglass morphology for the plane-of-sky component of the core magnetic field. Our data are consistent with previous BIMA maps, and the overall magnetic field geometries obtained with both instruments are similar. We resolve the main core into two components, FIR 5A and FIR 5B. A possible explanation for the asymmetrical field lies in depolarization effects due to the lack of internal heating from FIR 5B source, which may be in a prestellar evolutionary state. The field strength was estimated to be 2.2 mG, in agreement with previous BIMA data. We discuss the influence of a nearby H{\sc ii} region over the field lines at scales of $\sim 0.01$ pc. Although the hot component is probably compressing the molecular gas where the dust core is embedded, it is unlikely that the radiation pressure exceeds the magnetic tension. Finally, a complex outflow morphology is observed in CO (3 $\rightarrow$ 2) maps. Unlike previous maps, several features associated with dust condensations other than FIR 5 are detected.Comment: 48 pages, 12 figures, accepted for publication in The Astrophysical Journa

Stable splitting of bivariate spline spaces by Bernstein-Bézier methods

We develop stable splitting of the minimal determining sets for the spaces of bivariate C1 splines on triangulations, including a modified Argyris space, Clough-Tocher, Powell-Sabin and quadrilateral macro-element spaces. This leads to the stable splitting of the corresponding bases as required in Böhmer's method for solving fully nonlinear elliptic PDEs on polygonal domains

Selecting SaaS CRM Solution for SMEs

The use of CRM system has helped many organisations to manage and analyze business interaction with customers in several ways. However, Small and Medium-sized Enterprises (SMEs) are often struggling to find an optimal solution to fit their business and financial conditions. When faced with different SaaS-based CRM solutions, SMEs need to save investments in IT infrastructure, the cost of CRM deployment, and the maintenance cost. To select the best solution for the SME is critical for the business. This paper look at What systematic approach SMEs needs to follow when choosing the best SaaS CRM solution that would suit their company business strategy? To answer this question, this study presents a comprehensive decision-making framework for SaaS CRM evaluation and selection approach using the Analytical Hierarchical Process (AHP). The proposed selection approach is also applied to an SME, Biyemfat Enterprise, a small private real estate company. A case study of selecting a SaaS CRM solution for Biyemfat Enterprise is presented with an evaluation of the cost-benefit analysis

Self-consistent nonlinear kinetic simulations of the anomalous Doppler instability of suprathermal electrons in plasmas

Suprathermal tails in the distributions of electron velocities parallel to the magnetic field are found in many areas of plasma physics, from magnetic confinement fusion to solar system plasmas. Parallel electron kinetic energy can be transferred into plasma waves and perpendicular gyration energy of particles through the anomalous Doppler instability (ADI), provided that energetic electrons with parallel velocities v ≥ (ω + Ωce )/k are present; here Ωce denotes electron cyclotron frequency, ω the wave angular frequency and k the component of wavenumber parallel to the magnetic field. This phenomenon is widely observed in tokamak plasmas. Here we present the first fully self-consistent relativistic particle-in-cell simulations of the ADI, spanning the linear and nonlinear regimes of the ADI. We test the robustness of the analytical theory in the linear regime and follow the ADI through to the steady state. By directly evaluating the parallel and perpendicular dynamical contributions to j · E in the simulations, we follow the energy transfer between the excited waves and the bulk and tail electron populations for the first time. We find that the ratio Ωce /(ωpe + Ωce ) of energy transfer between parallel and perpendicular, obtained from linear analysis, does not apply when damping is fully included, when we find it to be ωpe /(ωpe + Ωce ); here ωpe denotes the electron plasma frequency. We also find that the ADI can arise beyond the previously expected range of plasma parameters, in particular when Ωce > ωpe . The simulations also exhibit a spectral feature which may correspond to observations of suprathermal narrowband emission at ωpe detected from low density tokamak plasmas

Open access at a crossroads: library publishing and bibliodiversity

The open access movement has gained momentum since the Budapest Open Access Initiative (BOAI) first launched twenty years ago. Notably, there has been a drastic increase in the number of open access articles. Concerns have been raised about equality and diversity issues, however, for researchers without an affiliation (e.g. independent, unemployed and retired researchers) and researchers on the ‘scientific periphery’ who are excluded from the gold open access model. This article argues that the gold open access model is destructive to the knowledge production ecosystem by addressing the importance of bibliodiversity and the ways in which library publishing can contribute to sustainable and equitable knowledge production