Biophysical, morphological, canopy optical property, and productivity data from the Superior National Forest

Described here are the results of a NASA field experiment conducted in the Superior National Forest near Ely, Minnesota, during the summers of 1983 and 1984. The purpose of the experiment was to examine the use of remote sensing to provide measurements of biophysical parameters in the boreal forests. Leaf area index, biomass, net primary productivity, canopy coverage, overstory and understory species composition data are reported for about 60 sites, representing a range of stand density and age for aspen and spruce. Leaf, needle, and bark high-resolution spectral reflectance and transmittance data are reported for the major boreal forest species. Canopy bidirectional reflectance measurements are provided from a helicopter-mounted Barnes Multiband Modular Radiometer (MMR) and the Thematic Mapper Simulator (TMS) on the NASA C-130 aircraft

Oxygen18 as Tracer in the Catalytic Decomposition of Potassium Chlorate

There is evidence that the catalytic action of manganese on the decomposition of potassium chlorate involves an alternate oxidation and reduction of the manganese. This evidence can be tested by enriching the oxygen of the catalyst with oxygen18 isotope. Oxygen liberated from chlorate decomposition with an enriched catalyst should contain oxygen18. Recently Forkushima et al (1) carried out a similar experiment. They enriched potassium chlorate with oxygen18 and decomposed it with Mn02.H20 containing ordinary oxygen. Water was formed from successive portions of the liberated oxygen. The density of this water was less than the density of water prepared from oxygen liberated from KC103 without a catalyst. They concluded that some unstable compound is formed between KC103 and Mn02, and that oxygen is liberated from this compound. They further concluded that only a limited portion of the catalyst is used in the reaction. In the present experiment the manganese dioxide was enriched with oxygen18, and the KC103 was normal. Isotopic ratios of liberated oxygen were determined directly by use of a mass spectrograph

Radiochlorine36 as a Tracer in the Decomposition of Potassium Chlorate

The thermal decomposition of potassium chlorate has been shown to be complex. Oxygen is evolved and, depending upon the conditions, various quantities of perchlorate are formed. At least two sets of equations have been proposed to explain the reaction. Otto and Fry (5) proposed that potassium chlorate decomposes by two simultaneous reactions

X-ray Timing of PSR J1852+0040 in Kesteven 79: Evidence of Neutron Stars Weakly Magnetized at Birth

The 105-ms X-ray pulsar J1852+0040 is the central compact object (CCO) in SNR Kes 79. We report a sensitive upper limit on its radio flux density of 12 uJy at 2 GHz using the NRAO GBT. Timing using XMM and Chandra over a 2.4 yr span reveals no significant change in its spin period. The 2 sigma upper limit on the period derivative leads, in the dipole spin-down formalism, to an energy loss rate E-dot < 7e33 ergs/s, surface magnetic field strength B_p < 1.5e11 G, and characteristic age tau_c = P/2P-dot > 8 Myr. This tau_c exceeds the age of the SNR by 3 orders of magnitude, implying that the pulsar was born spinning at its current period. However, the X-ray luminosity of PSR J1852+0040, L(bol) ~ 3e33(d/7.1 kpc)^2 ergs/s is a large fraction of E-dot, which challenges the rotation-powered assumption. Instead, its high blackbody temperature, 0.46+/-0.04 keV, small blackbody radius ~ 0.8 km, and large pulsed fraction, ~ 80%, may be evidence of accretion onto a polar cap, possibly from a fallback disk made of supernova debris. If B_p < 1e10 G, an accretion disk can penetrate the light cylinder and interact with the magnetosphere while resulting torques on the neutron star remain within the observed limits. A weak B-field is also inferred in another CCO, the 424-ms pulsar 1E 1207.4-5209, from its steady spin and soft X-ray absorption lines. We propose this origin of radio-quiet CCOs: the B-field, derived from a turbulent dynamo, is weaker if the NS is formed spinning slowly, which enables it to accrete SN debris. Accretion excludes neutron stars born with both B_p 0.1 s from radio pulsar surveys, where B_p 40 Myr) or recycled pulsars. Finally, such a CCO, if born in SN 1987A, could explain the non-detection of a pulsar there.Comment: 8 pages, 3 figures, to appear in The Astrophysical Journa

Airborne measurements of cloud-forming nuclei and aerosol particles in stabilized ground clouds produced by solid rocket booster firings

Airborne measurements of cloud volumes, ice nuclei and cloud condensation nuclei, liquid particles, and aerosol particles were obtained from stabilized ground clouds (SGCs) produced by Titan 3 launches at Kennedy Space Center, 20 August and 5 September 1977. The SGCs were bright, white, cumulus clouds early in their life and contained up to 3.5 g/m3 of liquid in micron to millimeter size droplets. The measured cloud volumes were 40 to 60 cu km five hours after launch. The SGCs contained high concentrations of cloud condensation nuclei active at 0.2%, 0.5%, and 1.0% supersaturation for periods of three to five hours. The SGCs also contained high concentrations of submicron particles. Three modes existed in the particle population: a 0.05 to 0.1 micron mode composed of aluminum-containing particles, a 0.2 to 0.8 micron mode, and a 2.0 to 10 micron mode composed of particles that contained primarily aluminum

Magnetar-like Emission from the Young Pulsar in Kes 75

We report detection of magnetar-like X-ray bursts from the young pulsar PSR J1846-0258, at the center of the supernova remnant Kes 75. This pulsar, long thought to be rotation-powered, has an inferred surface dipolar magnetic field of 4.9x10^13 G, higher than those of the vast majority of rotation-powered pulsars, but lower than those of the ~12 previously identified magnetars. The bursts were accompanied by a sudden flux increase and an unprecedented change in timing behavior. These phenomena lower the magnetic and rotational thresholds associated with magnetar-like behavior, and suggest that in neutron stars there exists a continuum of magnetic activity that increases with inferred magnetic field strength.Comment: 17 pages, 2 figures, accepted for publication in Science. Note: The content of this paper is embargoed until February 21, 200

An observational study of children interacting with an augmented story book

We present findings of an observational study investigating how young children interact with augmented reality story books. Children aged between 6 and 7 read and interacted with one of two story books aimed at early literacy education. The books pages were augmented using animated virtual 3D characters, sound, and interactive tasks. Introducing novel media to young children requires system and story designers to consider not only technological issues but also questions arising from story design and the design of interactive sequences. We discuss findings of our study and implications regarding the implementation of augmented story books

Relation and interactions among reading fluency and competence for adult education learners

This is the peer reviewed version of the following article: Mellard, D. F., Fall, E. E. and Woods, K. L. (2013), Relation and Interactions Among Reading Fluency and Competence for Adult Education Learners. Learning Disabilities Research & Practice, 28: 70–80. doi:10.1111/ldrp.12008, which has been published in final form at http://doi.org/10.1111/ldrp.12008. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Statistical analyses of data from an academically diverse sample of 276 adult basic and secondary education learners extends understanding of the relation of and interactions between oral reading fluency and reading competence indices. Significant interactions between total word rate and word error rate that differed in relation to two measures of reading competence suggest that adult literacy instructors should emphasize fluency instruction to a greater or lesser degree depending on whether the major goal of instruction is academic reading (e.g., being able to comprehend a textbook) or functional reading (e.g., being able to fill out a job application)