Kinetics of nitric oxide formation and decomposition

Experiments on shock wave structure were conducted in the 12 inch shock tube facility, and it is shown that this work was motivated by the need for improved kinetics for the modeling of NO production in space shuttle flow fields. The experiments on shock structure involved simultaneous observations of pressure and temperature on the wall of the shock tube during reflection of normal shock waves in inert gases

Enhanced Acoustic Emission in Relation to the Acoustic Halo Surrounding Active Region 11429

The use of acoustic holography in the high-frequency $p$-mode spectrum can resolve the source distributions of enhanced acoustic emissions within halo structures surrounding active regions. In doing so, statistical methods can then be applied to ascertain relationships with the magnetic field. This is the focus of this study. The mechanism responsible for the detected enhancement of acoustic sources around solar active regions has not yet been explained. Furthermore the relationship between the magnetic field and enhanced acoustic emission has not yet been comprehensively examined. We have used vector magnetograms from the \Helioseismic and Magnetic Imager (HMI) on-board the Solar Dynamics Observatory (SDO) to image the magnetic-field properties in the halo. We have studied the acoustic morphology of an active region, with a complex halo and "glories," and we have linked some acoustic properties to the magnetic-field configuration. In particular, we find that acoustic sources are significantly enhanced in regions of intermediate field strength with inclinations no different from the distributions found in the quiet Sun. Additionally we have identified a transition region between the active region and the halo, in which the acoustic source power is hindered by inclined fields of intermediate field strength. Finally, we have compared the results of acoustic emission maps, calculated from holography, and the commonly used local acoustic maps, finding that the two types of maps have similar properties with respect to the magnetic field but lack spatial correlation when examining the highest-powered regions.Comment: 19 pages, 8 figures, Accepted by Solar Physic

Kinetics of the reaction of nitric oxide with hydrogen

Mixtures of NO and H2 diluted in argon or krypton were heated by incident shock waves, and the infrared emission from the fundamental vibration-rotation band of NO at 5.3 microns was used to monitor the time-varying NO concentration. The reaction kinetics were studied in the temperature range 2400-4500 K using a shock-tube technique. The decomposition of nitric oxide behind the shock was found to be modeled well by a fifteen-reaction system. A principle result of the study was the determination of the rate constant for the reaction H + NO yields N + OH, which may be the rate-limiting step for NO removal in some combustion systems. Experimental values of k sub 1 were obtained for each test through comparisons of measured and numerically predicted NO profiles

Economic Evaluation in Global Perspective: A Bibliometric Analysis of the Recent Literature.

We present a bibliometric analysis of recently published full economic evaluations of health interventions and reflect critically on the implications of our findings for this growing field. We created a database drawing on 14 health, economic, and/or general literature databases for articles published between 1 January 2012 and 3 May 2014 and identified 2844 economic evaluations meeting our criteria. We present findings regarding the sensitivity, specificity, and added value of searches in the different databases. We examine the distribution of publications between countries, regions, and health areas studied and compare the relative volume of research with disease burden. We analyse authors' country and institutional affiliations, journals and journal type, language, and type of economic evaluation conducted. More than 1200 economic evaluations were published annually, of which 4% addressed low-income countries, 4% lower-middle-income countries, 14% upper-middle-income countries, and 83% high-income countries. Across country income levels, 53, 54, 86, and 100% of articles, respectively, included an author based in a country within the income level studied. Biomedical journals published 74% of economic evaluations. The volume of research across health areas correlates more closely with disease burden in high-income than in low-income and middle-income countries. Our findings provide an empirical basis for further study on methods, research prioritization, and capacity development in health economic evaluation

Economic Evaluation in Global Perspective: A Bibliometric Analysis of the Recent Literature.

We present a bibliometric analysis of recently published full economic evaluations of health interventions and reflect critically on the implications of our findings for this growing field. We created a database drawing on 14 health, economic, and/or general literature databases for articles published between 1 January 2012 and 3 May 2014 and identified 2844 economic evaluations meeting our criteria. We present findings regarding the sensitivity, specificity, and added value of searches in the different databases. We examine the distribution of publications between countries, regions, and health areas studied and compare the relative volume of research with disease burden. We analyse authors' country and institutional affiliations, journals and journal type, language, and type of economic evaluation conducted. More than 1200 economic evaluations were published annually, of which 4% addressed low-income countries, 4% lower-middle-income countries, 14% upper-middle-income countries, and 83% high-income countries. Across country income levels, 53, 54, 86, and 100% of articles, respectively, included an author based in a country within the income level studied. Biomedical journals published 74% of economic evaluations. The volume of research across health areas correlates more closely with disease burden in high-income than in low-income and middle-income countries. Our findings provide an empirical basis for further study on methods, research prioritization, and capacity development in health economic evaluation

Feasibility study of a 110 watt per kilogram lightweight solar array system

An investigation of the feasibility of a solar array panel subsystem which will produce 10,000 watts of electrical output at 1 A.U. with an overall beginning-of-life power-to-weight ratio of at least 110 watt/kg is reported. A description of the current baseline configuration which meets these requirements is presented. A parametric analysis of the single boom, two blanket planar solar array system was performed to arrive at the optimum system aspect ratio. A novel concept for the stiffening of a lightweight solar array by canting the solar cell blankets at a small angle to take advantage of the inherent in-plane stiffness to increase the symmetric out-of-plane frequency is introduced along with a preliminary analysis of the stiffening effect. A comparison of welded and soldered solar cell interconnections leads to the conclusion that welding is required on this ultralightweight solar array. The use of a boron/aluminum composite material in a BI-STEM type deployable boom is investigated as a possible advancement in the state-of-the-art

Decomposition of NO studied by infrared emission and CO laser absorption

A diagnostic technique for monitoring the concentration of NO using absorption of CO laser radiation was developed and applied in a study of the decomposition kinetics of NO. Simultaneous measurements of infrared emission by NO at 5.3 microns were also made to validate the laser absorption technique. The data were obtained behind incident shocks in NO-N2O-Ar (or Kr) mixtures, with temperatures in the range 2400-4100 K. Rate constants for dominant reactions were inferred from comparisons with computer simulations of the reactive flow

Long-term impact of wheat-based cropping systems on soil biological activity

Non-Peer Reviewe

Field evaluation of the "Bait-lamina test" to determine the soil microfauna feeding activity

Non-Peer ReviewedThe soil microfauna regulate nutrient cycling through predation on soil microorganisms but also through comminution of organic residues in soils. The feeding activity of the soil microfauna has a large impact on nutrient cycling and soil function, but is rarely considered because it is difficult to assess. The Baitlamina test was proposed as a practical mean to assess microfauna feeding activity. The test consists of vertically inserting 16-hole-bearing plastic sticks stuffed with a plant material preparation into the soil. We tested if the plant material used to prepare the bait would be differentially utilized by microfaunal population present under different plant species or mixtures of plants. We evaluated the Bait-lamina test in a 5-year old field experiment with five levels of plant communities (monocultures of Russian wild rye, switchgrass, green needlegrass, or western wheatgrass, and a grass mixture) distributed in four complete blocks, using six levels of bait flavour (Russian wild rye, switchgrass, green needlegrass, western wheatgrass, alfalfa, and wheat bran). Bait-lamina strips were equally spaced at five locations between plant rows. We found that the bait flavour had no significant (P = 0.22) effect on feeding, although the concentration of crude protein in the plant material used in the baits varied (P = 0.006) from 2.9% in switchgrass to 5.9% in Russian wild rye. We found low feeding activity in our field plots over the period of the test ( 13 June to 17 August 2005), with only 2.7% of the lamina (hole stuffing) showing signs of feeding. The data nevertheless revealed that microfauna feeding was more important close to the soil surface (0.5 mm deep), and in Russian wild rye plot mid-rows as compared to green needlegrass or switchgrass plots. Closer to plant rows, however, differences were not significant. We conclude that bait prepared with any plant material used in this study can be used to compare microfauna feeding in different plant stands. We recommend the use of a large number of replicated strips in agricultural field experiments where the microfauna may be scarce

Factors limiting soil microbial growth and activity in wheat-based cropping systems

Non-Peer ReviewedSeveral soil biochemical processes related to soil fertility are microbially mediated. We know very well the factors limiting crop production but know little of the factors limiting the soil microbial community. The goal of this study is to clarify if N, P and C limit soil microbial growth and biochemical processes in the wheat and fallow phases of rotations receiving different N, P and crop residue-C inputs. Soil samples were collected July 28, 2003, and brought to the laboratory. Soils samples were treated with an N, C or P solution, with water only, or left untreated, and incubated for 48 hours. At the end of the incubation period, soil microbial biomass N was determined along with denitrification and nitrogenase activities. The results showed that the microbial activities and growth were limited by soil moisture at the date of sampling. Denitrification and nitrogenase activities were limited by N, P or C. The limiting nutrients varied with N, P and C inputs associated with the cropping system, regardless to soil moisture. The limitation of these elements to soil microbial activity was more frequently encountered under fallow