Total and Merchantable Volume of White Spruce in Alaska

White spruce (Picea glauca [Moench] Voss) is a valuable commercial species found in interior and southcentral Alaska. Numerous regional and local volume tables or equations exist; however, no statewide model exists or has been tested for accuracy. There is a demand for an accurate model to determine the cubic-foot volume of white spruce trees in Alaska. Multiple models were developed for white spruce to estimate total and merchantable cubic-foot volume to a 2-, 4-, and 6-in. top. These multiple-entry (diameter and height) models were developed for both inside and outside bark volume from a 6-in. stump. The models were tested on a regional basis at various geographic locations and were shown to be highly accurate. The Alaska models chosen have R2 at or near 0.99 and mean square error from 0 to 0.16 for all models. These models are shown to be superior to other white spruce models in Alaska.This research was supported in part by the US Department of Agriculture, McIntire-Stennis Act Fund ALK-03-12, and by the School of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks

MP 2012-01

In 1994 the University of Alaska Fairbanks, School of Natural Resources and Agricultural Sciences, Agricultural and Forestry Experiment Station began a project to establish permanent sample plots (PSP) throughout the forests of northern and southcentral Alaska. Objectives of the project are to establish and maintain a system of PSPs to monitor forest growth, yield, forest health, and ecological conditions/change (Malone et al., 2009). To date, 603 PSPs have been established on 201 sites throughout interior and southcentral Alaska. The PSPs are square and 0.1 acre in size and in clusters of three. PSPs are remeasured at a five-year interval. The number of plot remeasurements after establishment ranges from one to three times. A large amount of data is collected at each site at time of establishment and at subsequent remeasurements. Four databases contain all the data: tree measurement and characteristics, site description, regeneration, and vegetation data. Vegetation data collected on the 0.1 acre PSPs includes species (trees shrub, herb, grass, and non-vascular plants) and cover, an estimate of the amount of the plot covered by the crown of each species (cover class) (Daubenmire, 1959). The vegetation database can be used by land managers and researchers to study species diversity and forest succession in addition to long-term monitoring of forest health. The species listed in Appendix 1 and in the vegetation database are presented by categories: tree, shrub, herb, grass, rush, sedge, fern, club moss, lichen, moss, and liverwort

Calculation of W b bbar Production via Double Parton Scattering at the LHC

We investigate the potential to observe double parton scattering at the Large Hadron Collider in p p -> W b bbar X -> l nu b bbar X at 7 TeV. Our analysis tests the efficacy of several kinematic variables in isolating the double parton process of interest from the single parton process and relevant backgrounds for the first 10 inverse fb of integrated luminosity. These variables are constructed to expose the independent nature of the two subprocesses in double parton scattering, pp -> l nu X and pp -> b bbar X. We use next-to-leading order perturbative predictions for the double parton and single parton scattering components of W b bbar and for the pertinent backgrounds. The next-to-leading order contributions are important for a proper description of some of the observables we compute. We find that the double parton process can be identified and measured with significance S/sqrt(B) ~ 10, provided the double parton scattering effective cross section sigma_{eff} ~ 12 mb.Comment: 21 pages, 9 figures; v2: improved presentation and figures, version published in Phys. Rev.

NNLO QCD Corrections to t-channel Single Top-Quark Production and Decay

We present a fully differential next-to-next-to-leading order calculation of t-channel single top-quark production and decay at the LHC under narrow-width approximation and neglecting cross-talk between incoming protons. We focus on the fiducial cross sections at 13 TeV, finding that the next-to-next-to-leading order QCD corrections can reach the level of -6%. The scale variations are reduced to the level of a percent. Our results can be used to improve experimental acceptance estimates and the measurements of the single top-quark production cross section and the top-quark electroweak couplings.Comment: 6 pages, 4 figures, version appear on PRD rapid communicatio

Excitation and Imaging of Resonant Optical Modes of Au Triangular Nano-Antennas Using Cathodoluminescence Spectroscopy

Cathodoluminescence (CL) imaging spectroscopy is an important technique to understand resonant behavior of optical nanoantennas. We report high-resolution CL spectroscopy of triangular gold nanoantennas designed with near-vacuum effective index and very small metal-substrate interface. This design helped in addressing issues related to background luminescence and shifting of dipole modes beyond visible spectrum. Spatial and spectral investigations of various plasmonic modes are reported. Out-of-plane dipole modes excited with vertically illuminated electron beam showed high-contrast tip illumination in panchromatic imaging. By tilting the nanostructures during fabrication, in-plane dipole modes of antennas were excited. Finite-difference time-domain simulations for electron and optical excitations of different modes showed excellent agreement with experimental results. Our approach of efficiently exciting antenna modes by using low index substrates is confirmed both with experiments and numerical simulations. This should provide further insights into better understanding of optical antennas for various applications.Comment: To be published in JVST B (accepted, Sep 2010) (15 pages, 6 figures, originally presented at EIPBN 2010

Energetic neutral atoms: Imaging the magnetospheric ring current

Magnetospheric imaging is a new discipline whose goal is to make pictures of the energetic particle populations trapped in the magnetic field of Earth (or any other planet). This project demonstrated the technical feasibility and scientific validity of magnetospheric imaging using energetic neutral atoms (ENA) with the publication and quantitative analysis of the first ENA images ever obtained from space. ENA's are produced when singly-charged energetic (approximately 100 keV) trapped ions make an atomic collision with the neutral hydrogen atoms which boil of the top of the Earth's atmosphere. These hydrogen atoms suffuse the entire trapping volume of the magnetosphere. The energetic ion steals the electron from the atmospheric hydrogen, so the energetic ion is transformed into an energetic neutral atom with a velocity of several thousands of kilometers/second. Moreover, the new-born ENA preserves the velocity that the trapped ion had at the time of the collision. Consequently, any population of energetic ions emits ENA's

Higgs Boson Search Sensitivity in the H→WWH \to WW Dilepton Decay Mode at s=7\sqrt s = 7 and 10 TeV

Prospects for discovery of the standard model Higgs boson are examined at center of mass energies of $7$ and $10$ TeV at the CERN Large Hadron Collider. We perform a simulation of the signal and principal backgrounds for Higgs boson production and decay in the $W^+ W^-$ dilepton mode, finding good agreement with the ATLAS and CMS collaboration estimates of signal significance at 14 TeV for Higgs boson masses near $m_H = 160$~GeV. At the lower energy of $7$~TeV, using the same analysis cuts as these collaborations, we compute expected signal sensitivities of about $2$ standard deviations ($\sigma$'s) at $m_H = 160$~GeV in the ATLAS case, and about 3.6~$\sigma$ in the CMS case for $1$~fb$^{-1}$ of integrated luminosity. Integrated luminosities of 8~$\rm{fb}^{-1}$ and 3~$\rm{fb}^{-1}$ are needed in the ATLAS case at $7$ and $10$~TeV, respectively, for $5~\sigma$ level discovery. In the CMS case, the numbers are 2~$\rm{fb}^{-1}$ and 1~$\rm{fb}^{-1}$ at $7$ and $10$~TeV. Our different stated expectations for the two experiments arise from the more restrictive analysis cuts in the CMS case. Recast as exclusion limits, our results show that with $1~{\rm fb}^{-1}$ of integrated luminosity at 7~TeV, the LHC may be able to exclude $m_H$ values in the range 160 to 180~GeV provided no signal is seen.Comment: 29 pages, 8 figures. New results on estimated discovery reach for both CMS and ATLAS, as well as exclusion limits, along with comparisons with Tevatron possibilities. References added