Aircraft energy efficiency laminar flow control wing design study

An engineering design study was performed in which laminar flow control (LFC) was integrated into the wing of a commercial passenger transport aircraft. A baseline aircraft configuration was selected and the wing geometry was defined. The LFC system, with suction slots, ducting, and suction pumps was integrated with the wing structure. The use of standard aluminum technology and advanced superplastic formed diffusion bonded titanium technology was evaluated. The results of the design study show that the LFC system can be integrated with the wing structure to provide a structurally and aerodynamically efficient wing for a commercial transport aircraft

The impact of space and space-related activities on a local economy. a case study of boulder, colorado. part i- the input-output analysis

Impact of space and space-related activities on industry and general economy of Boulder, Colorad

Cross Section and Angular Distributions of the (d, p) and (d, n) Reactions in C12 from 1.8 to 6.1 Mev

The reaction C12(d, p)C13 has been studied from a deuteron bombarding energy of 1.8 to 6.1 Mev. Resonances were found at 2.47, 2.67, 2.99, 3.39, 4.00, 4.6, 4.8, 5.34, and 5.64 Mev. Angular distributions of protons leaving C13 in the ground state show a pronounced Butler peak at 25° over the entire deuteron energy range. The angular distributions can be explained by assuming small amplitudes for compound nucleus formation interfering with large stripping amplitudes. Angular distributions of the lower energy group of protons leaving C13 excited to 3.09 Mev show a pronounced Butler peak at 0° and an even smaller contribution of compound nucleus formation. The reaction C12(d, n)N13 was also studied, and showed similar resonances and angular distributions. An analysis is made of the phase difference between the resonant and nonresonant parts of the cross section for the (d, p) reaction near the resonance at 4.00 Mev

Neutrons and Gamma Rays from the Alpha-Particle Bombardment of Be9, B10, B11, C13, and O18

Excitation curves at 0° and 90° were studied for neutrons and γ rays produced in bombardment of thin targets of Be9, B10, B11, C13, and O18 by α particles with energies of from 1.8 to 5.3 Mev. Resonances were observed in the Be9(α, n)C12 reaction at bombarding energies of 1.9, 2.3, 2.6, 3.98, 4.4, and 5.0 Mev. The C13(α, n)O16 reaction showed resonances at 2.09, 2.25, 2.42, 2.605, 2.69, 2.775, 2.825, 3.09, 3.33, 3.42, 3.67, 3.73, 4.125, 4.42, 4.50, 4.63, 4.75, and 5.05 Mev. The B10(α, n)N13 excitation curve has resonances at 2.16, 2.25, 2.90, 4.53, 4.85, and 5.36 Mev, while the γ-ray yield from the B10(α, pγ)C13 reaction showed all these as well as resonances at 3.6 and 3.95 Mev. The B11(α, n)C13 reaction has resonances at bombarding energies of 2.06, 2.60, 2.93, 2.97, 3.23, 3.54, 3.72, 3.92, 4.25, 4.34, and 5.00 Mev. The O18(α, n)Ne21 reaction was studied with a thicker target (90-130 kev). Resonances in the neutron yield were resolved at 2.21, 2.47, 2.57, 2.72, 2.94, 3.24, 3.63, 3.91, 4.12, 4.22, 4.33, 4.52, and 4.82 Mev. Cross sections and widths of the resonances in the various reactions were determined

A LANDSAT study of ephemeral and perennial rangeland vegetation and soils

The author has identified the following significant results. Several methods of computer processing were applied to LANDSAT data for mapping vegetation characteristics of perennial rangeland in Montana and ephemeral rangeland in Arizona. The choice of optimal processing technique was dependent on prescribed mapping and site condition. Single channel level slicing and ratioing of channels were used for simple enhancement. Predictive models for mapping percent vegetation cover based on data from field spectra and LANDSAT data were generated by multiple linear regression of six unique LANDSAT spectral ratios. Ratio gating logic and maximum likelihood classification were applied successfully to recognize plant communities in Montana. Maximum likelihood classification did little to improve recognition of terrain features when compared to a single channel density slice in sparsely vegetated Arizona. LANDSAT was found to be more sensitive to differences between plant communities based on percentages of vigorous vegetation than to actual physical or spectral differences among plant species

An Accurate Determination of the Exchange Constant in Sr_2CuO_3 from Recent Theoretical Results

Data from susceptibility measurements on Sr_2CuO_3 are compared with recent theoretical predictions for the magnetic susceptibility of the antiferromagnetic spin-1/2 Heisenberg chain. The experimental data fully confirms the theoretical predictions and in turn we establish that Sr_2CuO_3 behaves almost perfectly like a one-dimensional antiferromagnet with an exchange coupling of J = 1700^{+150}_{-100}K.Comment: revised and reformatted paper with new title to appear in Phys. Rev B (Feb.1996). 3 pages (revtex) with 3 embedded figures (macro included). A complete postscript file is available from http://fy.chalmers.se/~eggert/expsusc.ps or by request from [email protected]

Severe cutaneous toxicity following treatment with radiotherapy and cetuximab: a case report

While the addition of cetuximab to radiotherapy improves clinical outcomes in locoregionally advanced head and neck squamous cell cancers, there are a small number of reports of severe radiation dermatitis occurring with this therapeutic combination. We present the case of a 69 year old male who developed severe radiation dermatitis following treatment with cetuximab and radiotherapy for a locoregionally advanced head and neck squamous cell cancer

Spin-Peierls transitions in magnetic donor-acceptor compounds of tetrathiafulvalene (TTF) with bisdithiolene metal complexes

The spin-Peierls transition is considered as a progressive spin-lattice dimerization occurring below a transition temperature in a system of one-dimensional antiferromagnetic Heisenberg chains. In the simplest theories, the transition is second order and the ground state is a singlet with a magnetic gap. The historical origins and theoretical development of the concept are examined. Magnetic susceptibility and EPR measurements on the π-donor-acceptor compounds TTF·MS4C4(CF3)4 (M=Cu, Au; TTF is tetrathiafulvalene) are reported. These compounds exhibit clearly the characteristics of the spin-Peierls transition in reasonably good agreement with a mean-field theory. The susceptibility of each compound has a broad maximum near 50 K, while the transitions occur at 12 and 2.1 K for M=Cu and Au, respectively. EPR linewidth observations over a broad temperature range are examined. Areas for further experimental and theoretical work are indicated, and a critical comparison is made of related observations on other materials

Observation of a Spin-Peierls Transition in a Heisenberg Antiferromagnetic Linear-Chain System

Magnetic-susceptibility and EPR measurements are reported which provide the first unambiguous evidence for a spin-Peierls transition in a system of linear one-dimensional antiferromagnetic Heisenberg chains. The material studied is TTFCuS4C4(CF3)4 (TFF stands for tetrathiafulvalinium). At 12 K, the spin-lattice system undergoes a second-order phase transition to a singlet ground state

Thermal and magnetic study of exchange in the quasi-1-D molecular compound, TTF⋅PtS\u3csub\u3e4\u3c/sub\u3eC\u3csub\u3e4\u3c/sub\u3e(CF\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e4\u3c/sub\u3e

Single crystalmagnetic susceptibility results from 2.5 K to 270 K and specific heat results from 3 K to 16 K are reported for TTF⋅PtS4C4(CF3)4, (TTF=tetrathiafulvalene). The combined results are analyzed using a simple model which ignores differences between the two types of S=1/2 spin carriers and involves a system of ferromagnetic chains treated ’’exactly’’, with interchain antiferromagnetic interaction evaluated in a mean field approximation. Above an apparent ordering transition at 8 K, the susceptibility is well described by the model irrespective of whether the ferromagnetic exchange is Heisenberg, Ising or intermediate to these. The magnetic contribution to the specific heat is obtained using earlier results for the isostructural Au compound. Comparison with specific heat calculations for the Heisenberg, Ising and intermediate cases successfully narrows the ambiguity to an intermediate anisotropic exchange close to the Heisenberg limit