Letter from J. H. Ackerman

Letter concerning programs of domestic science and art in Oregon

Multiangle observations of Arctic clouds from FIRE ACE: June 3, 1998, case study

In May and June 1998 the Airborne Multiangle Imaging Spectroradiometer (AirMISR) participated in the FIRE Arctic Cloud Experiment (ACE). AirMISR is an airborne instrument for obtaining multiangle imagery similar to that of the satellite-borne MISR instrument. This paper presents a detailed analysis of the data collected on June 3, 1998. In particular, AirMISR radiance measurements are compared with measurements made by two other instruments, the Cloud Absorption Radiometer (CAR) and the MODIS airborne simulator (MAS), as well as to plane-parallel radiative transfer simulations. It is found that the AirMISR radiance measurements and albedo estimates compare favorably both with the other instruments and with the radiative transfer simulations. In addition to radiance and albedo, the multiangle AirMISR data can be used to obtain estimates of cloud top height using stereoimaging techniques. Comparison of AirMISR retrieved cloud top height (using the complete MISR-based stereoimaging approach) shows excellent agreement with the measurements from the airborne Cloud Lidar System (CLS) and ground-based millimeterwave cloud radar

Tuning and Switching a Plasmonic Quantum Dot Sandwich in a Nematic Line Defect

We study the quantum-mechanical effects arising in a single semiconductor core/shell quantum dot controllably sandwiched between two plasmonic nanorods. Control over the position and the sandwich confinement structure is achieved by the use of a linear-trap, liquid-crystal line defect and laser tweezers that push the sandwich together. This arrangement allows for the study of exciton plasmon interactions in a single structure, unaltered by ensemble effects or the complexity of dielectric interfaces. We demonstrate the effect of plasmonic confinement on the photon-antibunching behavior of the quantum dot and its luminescence lifetime. The quantum dot behaves as a single emitter when nanorods are far away from the quantum dot but shows possible multiexciton emission and a significantly decreased lifetime when tightly confined in a plasmonic sandwich. These findings demonstrate that liquid crystal defects, combined with laser tweezers, enable a versatile platform to study plasmonic coupling phenomena in a nanoscale laboratory, where all elements can be arranged almost at will.Comment: Supporting information at the en

Nuclear matrix element for two neutrino double beta decay from 136Xe

The nuclear matrix element for the two neutrino double beta decay (DBD) of 136Xe was evaluated by FSQP (Fermi Surface Quasi Particle model), where experimental GT strengths measured by the charge exchange reaction and those by the beta decay rates were used. The 2 neutrino DBD matrix element is given by the sum of products of the single beta matrix elements via low-lying (Fermi Surface) quasi-particle states in the intermediate nucleus. 136Xe is the semi-magic nucleus with the closed neutron-shell, and the beta + transitions are almost blocked. Thus the 2 neutrino DBD is much suppressed. The evaluated 2 neutrino DBD matrix element is consistent with the observed value.Comment: 7 pages 6 figure

Beyond Outerplanarity

We study straight-line drawings of graphs where the vertices are placed in convex position in the plane, i.e., convex drawings. We consider two families of graph classes with nice convex drawings: outer $k$-planar graphs, where each edge is crossed by at most $k$ other edges; and, outer $k$-quasi-planar graphs where no $k$ edges can mutually cross. We show that the outer $k$-planar graphs are $(\lfloor\sqrt{4k+1}\rfloor+1)$-degenerate, and consequently that every outer $k$-planar graph can be $(\lfloor\sqrt{4k+1}\rfloor+2)$-colored, and this bound is tight. We further show that every outer $k$-planar graph has a balanced separator of size $O(k)$. This implies that every outer $k$-planar graph has treewidth $O(k)$. For fixed $k$, these small balanced separators allow us to obtain a simple quasi-polynomial time algorithm to test whether a given graph is outer $k$-planar, i.e., none of these recognition problems are NP-complete unless ETH fails. For the outer $k$-quasi-planar graphs we prove that, unlike other beyond-planar graph classes, every edge-maximal $n$-vertex outer $k$-quasi planar graph has the same number of edges, namely $2(k-1)n - \binom{2k-1}{2}$. We also construct planar 3-trees that are not outer $3$-quasi-planar. Finally, we restrict outer $k$-planar and outer $k$-quasi-planar drawings to \emph{closed} drawings, where the vertex sequence on the boundary is a cycle in the graph. For each $k$, we express closed outer $k$-planarity and \emph{closed outer $k$-quasi-planarity} in extended monadic second-order logic. Thus, closed outer $k$-planarity is linear-time testable by Courcelle's Theorem.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

Aerosol Data Sources and Their Roles within PARAGON

We briefly but systematically review major sources of aerosol data, emphasizing suites of measurements that seem most likely to contribute to assessments of global aerosol climate forcing. The strengths and limitations of existing satellite, surface, and aircraft remote sensing systems are described, along with those of direct sampling networks and ship-based stations. It is evident that an enormous number of aerosol-related observations have been made, on a wide range of spatial and temporal sampling scales, and that many of the key gaps in this collection of data could be filled by technologies that either exist or are expected to be available in the near future. Emphasis must be given to combining remote sensing and in situ active and passive observations and integrating them with aerosol chemical transport models, in order to create a more complete environmental picture, having sufficient detail to address current climate forcing questions. The Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) initiative would provide an organizational framework to meet this goal

National counter-terrorism (C-T) policies and challenges to human rights and civil liberties: Case study of United Kingdom

In the UK the rise post-2005 in “home-grown” terrorism, relying to a significant extent on strikes on soft targets by “self-starters,” means that the search for effective preventive measures remains a continuing concern. Below a number of the preventive counter-terror measures adopted post-9/11, and incrementally strengthened in response to the current threat, are found to fall into three categories and represent interventions at the stages in the path toward attacks. This chapter focuses on selected examples of these preventive measures. In terms of three key stages, firstly, there is the attempt to prevent radicalization, under the “Prevent” strategy. A second strategy relies on taking certain measures to control the activities of those considered likely – on the balance of probabilities – to engage in terrorist-related activity. A third preventive strategy relies on the special terrorism offences under the Terrorism Acts 2000 and 2006, as amended, intended to allow for intervention at a very early stage in terrorist plots and in preparing or instigating terrorist acts (“precursor” offences)