Elliptic operators in odd subspaces

An elliptic theory is constructed for operators acting in subspaces defined via odd pseudodifferential projections. Subspaces of this type arise as Calderon subspaces for first order elliptic differential operators on manifolds with boundary, or as spectral subspaces for self-adjoint elliptic differential operators of odd order. Index formulas are obtained for operators in odd subspaces on closed manifolds and for general boundary value problems. We prove that the eta-invariant of operators of odd order on even-dimesional manifolds is a dyadic rational number.Comment: 27 page

Experimental determination of the absorption strength in absorbing chaotic cavities

Due to the experimental necessity we present a formula to determine the absorption strength by power losses inside a chaotic system (cavities, graphs, acoustic resonators, etc) when the antenna coupling, always present in experimental measurements, is taken into account. This is done by calculating the average of the absorption coefficient as a function of the absorption strength and the coupling of the antenna to the system, in the one channel case.Comment: 6 pages, 3 figures, Submitted to Phys. Rev.

Infiltration and short-term movement of nitrogen in a silt-loam soil typical of rice cultivation in Arkansas

Rice production in Arkansas is one of the top three crop commodities in terms of cash receipts. Researchers and farmers report that nitrogen (N) needs to be managed according to a variety of factors with two important ones being soil and fertilizer type. The objectives of this experiment were to determine: 1) the degree to which floodwater-incorporated N applied as urea or as ammonium sulfate infiltrates intact cores (7.2-cm dia., 10-cm depth) containing DeWitt siltloam soil, and 2) the distribution of N during 12 h of ponding. Inorganic-N concentrations were analyzed at 2-cm depth intervals in cores following removal of the flood. Nitrogen from applied fertilizer was recovered as ammonium. Ammonium sulfate-N remained in the top 4 cm of soil with concentrations of 375 µg N g-1 in the surface 2 cm and 300 µg N g-1 at the 2 - 4 cm depth after 12 hr of ponding. At all depth intervals below 4 cm, ammonium sulfate-N remained below 30 µg N g-1. In contrast, after 12 h of ponding, N in soil receiving urea was 105 µg N g-1 in the top 2 cm and 173 µg N g-1 at 2-4 cm. At 4-6, 6-8, and 8-10 cm, N was 109, 108, and 35 µg N g-1, respectively, after 12 h of ponding. These results demonstrate immediate and deeper movement of ammonium into silt loam soil receiving urea as compared to ammonium sulfate, demonstrating how the form of N in fertilizer affects its movement into the soil profile

Summary of the recent short-haul systems studies

The results of several NASA sponsored high density short haul air transportation systems studies are reported as well as analyzed. Included are the total STOL systems analysis approach, a companion STOL composites study conducted in conjunction with STOL systems studies, a STOL economic assessment study, an evaluation of STOL aircraft with and without externally blown flaps, an alternative STOL systems for the San Francisco Bay Area, and the quiet, clean experimental engine studies. Assumptions and results of these studies are summarized, their differences, analyzed, and the results compared with those in-house analyses performed by the Systems Studies Division of the NASA-Ames Research Center. Pertinent conclusions are developed and the more significant technology needs for the evaluation of a viable short haul transportation system are identified

Statistics of eigenfunctions in open chaotic systems: a perturbative approach

We investigate the statistical properties of the complexness parameter which characterizes uniquely complexness (biorthogonality) of resonance eigenstates of open chaotic systems. Specifying to the regime of isolated resonances, we apply the random matrix theory to the effective Hamiltonian formalism and derive analytically the probability distribution of the complexness parameter for two statistical ensembles describing the systems invariant under time reversal. For those with rigid spectra, we consider a Hamiltonian characterized by a picket-fence spectrum without spectral fluctuations. Then, in the more realistic case of a Hamiltonian described by the Gaussian Orthogonal Ensemble, we reveal and discuss the r\^ole of spectral fluctuations

Changing career paths in environmental, soil, and water science and crop management: Survey results

Periodic assessment of goals is critical to maintaining a successful academic program. Two surveys were designed and distributed to alumni and potential employers of graduates of the Department of Crop, Soil, and Environmental Sciences (CSES) in the summer of 2002 to assess the profitability of advanced degrees in terms of earning potential and to determine sectors of the workforce currently employing department graduates. The CSES Alumni Satisfaction Survey was sent to 792 department alumni, including graduates of the previous Agronomy program as well as the current Crop, Soil, and Environmental Sciences program. The CSES Employer Survey was distributed to 281 professionals and provided valuable information concerning current workforce requirements of college graduates. Survey results suggested that alumni career paths are changing; alumni are employed quickly, but fewer alumni are self- or government-employed while more are working in industry positions. Results from the CSES Employer Survey suggest that alumni are earning salaries typical for this region. Alumni salaries also indicated that advanced degrees are profitable in that the number of alumni reporting higher-end salaries increased to a greater extent among M.S. and Ph.D. graduates. These results will be used to enhance recruitment of prospective students and to improve advisement of current departmental students. Ultimately, the CSES Department hopes to increase enrollment, student satisfaction with degree programs, and career preparedness

Manipulation and Generation of Supercurrent in Out-of-Equilibrium Josephson Tunnel Nanojunctions

We demonstrate experimentally manipulation of supercurrent in Al-AlO_x-Ti Josephson tunnel junctions by injecting quasiparticles in a Ti island from two additional tunnel-coupled Al superconducting reservoirs. Both supercurrent enhancement and quenching with respect to equilibrium are achieved. We demonstrate cooling of the Ti line by quasiparticle injection from the normal state deep into the superconducting phase. A model based on heat transport and non-monotonic current-voltage characteristic of a Josephson junction satisfactorily accounts for our findings.Comment: 4 pages, 4 colour figures, published versio

Absolute rate coefficients for photorecombination of berylliumlike and boronlike silicon ions

We report measured rate coefficients for electron-ion recombination for Si10+ forming Si9+ and for Si9+ forming Si8+, respectively. The measurements were performed using the electron-ion merged-beams technique at a heavy-ion storage ring. Electron-ion collision energies ranged from 0 to 50 eV for Si9+ and from 0 to 2000 eV for Si10+, thus, extending previous measurements for Si10+ [Orban et al. 2010, Astrophys. J. 721, 1603] to much higher energies. Experimentally derived rate coefficients for the recombination of Si9+ and Si10+ ions in a plasma are presented along with simple parameterizations. These rate coefficients are useful for the modeling of the charge balance of silicon in photoionized plasmas (Si9+ and Si10+) and in collisionally ionized plasmas (Si10+ only). In the corresponding temperature ranges, the experimentally derived rate coefficients agree with the latest corresponding theoretical results within the experimental uncertainties.Comment: 17 pages, 7 figures, 3 tables, 66 references, submitted to the J. Phys. B special issue on atomic and molecular data for astrophysicist

Impact of Carbon Pricing on Low-Carbon Innovation and Deep Decarbonisation : Controversies and Path Forward

Acord transformatiu CRUE-CSICUnidad de excelencia María de Maeztu CEX2019-000940-MThere is an ongoing discussion about the effectiveness of carbon pricing, with a strong division between optimists and pessimists. A recent review study by Lilliestam, Patt and Bersalli (2021) of the impact of carbon pricing on low-carbon innovation and deep carbonization concludes that there is no evidence for such an impact. We evaluate this study and identify various shortcomings of it, which together cast strong doubts on its main conclusion. Instead, we conclude, based on the studies reviewed by the authors and additional, overlooked literature, that carbon pricing has had a small but positive and significant effect on low-carbon innovation. Our evaluation provides lessons for undertaking a systematic and objective review of research on this topic. Since the main goal of carbon pricing is changing choices by firms and consumers that affect carbon emissions, we also point the reader towards recent evidence for the broader effectiveness of carbon pricing

Tired of climate targets? Shift focus of IPCC scenarios from emission and growth targets to policies

Unidad de excelencia María de Maeztu CEX2019-000940-MAcord transformatiu CRUE-CSICUTP en procés de revisióClimate change has revived the debate on growth-versus-environment. In line with this, recently it has been proposed to shift the target focus of IPCC scenarios from emissions to post-growth. We argue here that this confounds ends and means, since while reduction of growth may be an outcome of good climate policies, it should not be a goal in itself. In fact, a post- or degrowth goal would mean an ineffective and costly way to reduce emissions. Instead, we suggest that the debate about pursuing economic growth versus achieving climate goals will become more transparent and policy-relevant through refocusing scenarios from targets to policy