Challenges and Rewards of Single Crystal Flux Growth: Physical Properties of Structurally Related Ln-Ru-Al Intermetallics

The availability of single crystals is vital for understanding the intrinsic properties of crystalline materials. The flux growth method is a versatile technique which may be used to grow single crystals. However, their synthesis can often be challenging, especially when a competing phase is very robust. Herein, we study the growth competition between structurally related compounds in the Ln-Ru-Al phase space. We demonstrate the benefits of single crystals and suggest methods to grow competing phases. CeRu2Al10 has garnered interest due to its higher ordering temperate than expected from de Gennes scaling and its metal-to-insulator transition at the same temperature. Here, we report the magnetic and transport properties of three sets of compounds which are structurally related to CeRu2Al10: LnRu2Al10 (Ln = Pr, Gd, Yb), CeRu4(Al,Si)15.58, and Ln2Ru3Al15 (Ln = Ce, Gd, Tb). We find that despite the structural similarities, none of these compound display properties similar to those of CeRu2Al10. Our extensive study of these structurally related compounds allows us to draw conclusions about the structure-property relationships in these systems

Acute Jaundice in a Six-year-old: An Unusual Presentation of Atypical Kawasaki Disease

Kawasaki disease (KD) is a rare vasculitis of childhood that is critical to recognize and treat due to associated morbidity and mortality. A six-year-old male presented to our emergency department (ED) afebrile but with reported recent fevers. Exam revealed jaundice and erythematous tongue with papules, and laboratory studies indicated a direct hyperbilirubinemia. Admitted for evaluation, he developed continuous fever, increasing maculopapular rash, and subsequent desquamation of hands and feet. He ultimately met criteria for incomplete KD, was treated with intravenous immunoglobulin, and avoided cardiac complications. This presentation of incomplete KD with hyperbilirubinemia is rare because the patient was afebrile at ED presentation

Spatial filtering experiment with the Murchison Widefield Array

Spatial Radio Frequency Interference (RFI) filtering offers both RFI rejection and potential signal-of-interest recovery. It is as such an attractive RFI mitigation technique for radio interferometry. This paper describes an experiment of spatial filtering of an amateur radio transmission originating from the International Space Station corrupting the Murchison Widefield Array low-frequency radio telescope

Discovering Communities through Friendship

We introduce a new method for detecting communities of arbitrary size in an undirected weighted network. Our approach is based on tracing the path of closest‐friendship between nodes in the network using the recently proposed Generalized Erds Numbers. This method does not require the choice of any arbitrary parameters or null models, and does not suffer from a system‐size resolution limit. Our closest‐friend community detection is able to accurately reconstruct the true network structure for a large number of real world and artificial benchmarks, and can be adapted to study the multi‐level structure of hierarchical communities as well. We also use the closeness between nodes to develop a degree of robustness for each node, which can assess how robustly that node is assigned to its community. To test the efficacy of these methods, we deploy them on a variety of well known benchmarks, a hierarchal structured artificial benchmark with a known community and robustness structure, as well as real‐world networks of coauthorships between the faculty at a major university and the network of citations of articles published in Physical Review. In all cases, microcommunities, hierarchy of the communities, and variable node robustness are all observed, providing insights into the structure of the network.Engineering and Applied SciencesPhysic

Using Moored Arrays and Hyperspectral Aerial Imagery to Develop Nutrient Criteria for New Hampshire\u27s Estuaries

Increasing nitrogen concentrations and declining eelgrass beds in Great Bay, NH are clear indicators of impending problems for the state’s estuaries. A workgroup established in 2005 by the NH Department of Environmental Services and the NH Estuaries Project (NHEP) adopted eelgrass survival as the water quality target for nutrient criteria development for NH’s estuaries. In 2007, the NHEP received a grant from the U.S. Environmental Protection Agency to collect water quality information including that from moored sensors and hyper-spectral imagery data of the Great Bay Estuary. Data from the Great Bay Coastal Buoy, part of the regional Integrated Ocean Observing System (IOOS), were used to derive a multivariate model of water clarity with phytoplankton, Colored Dissolved Organic Matter (CDOM), and non-algal particles. Non-algal particles include both inorganic and organic matter. Most of the temporal variability in the diffuse attenuation coefficient of Photosynthetically Available Radiation (PAR) was associated with non-algal particles. However, on a mean daily basis non-algal particles and CDOM contributed a similar fraction (~30 %) to the attenuation of light. The contribution of phytoplankton was about a third of the other two optically important constituents. CDOM concentrations varied with salinity and magnitude of riverine inputs demonstrating its terrestrial origin. Non-algal particle concentration also varied with river flow but also wind driven resuspension. Twelve of the NHEP estuarine assessment zones were observed with the hyperspectral aerial imagery on August 29 and October 17. A concurrent in situ effort included buoy measurements, continuous along-track sampling, discrete water grab samples, and vertical profiles of light attenuation. PAR effective attenuation coefficients retrieved from deep water regions in the imagery agreed well with in-situ observations. Water clarity was lower and optically important constituent concentrations were higher in the tributaries. Eelgrass survival depth, estimated as the depth at which 22% of surface light was available, ranged from less than half a meter to over two meters. The best water clarity was found in the Great Bay (GB), Little Bay (LB), and Lower Piscataqua River (LPR) assessment zones. Absence of eelgrass from these zones would indicate controlling factors other than water clarity

Scattering of electromagnetic waves in metamaterial superlattices

The authors study experimentally both transmission and reflection of microwave radiation from metamaterialsuperlattices created by layers of periodically arranged wires and split-ring resonators. The authors measure the dependence of the metamaterial resonance on the spatial period of the superlattice and demonstrate resonance broadening and splitting for the binary metamaterial structures.The authors acknowledge support from the Australian Research Council and thank Ekmel Ozbay for providing additional details of the experimental results published earlier by his group