Improvement and evaluation of simulated global biogenic soil NO emissions in an AC-GCM

Biogenic NO emissions from soils (SNOx) play important direct and indirect roles in tropospheric chemistry. The most widely applied algorithm to calculate SNOx in global models was published 15 years ago by Yienger and Levy (1995), and was based on very few measurements. Since then, numerous new measurements have been published, which we used to build up a compilation of world wide field measurements covering the period from 1978 to 2010. Recently, several satellite-based top-down approaches, which recalculated the different sources of NOx (fossil fuel, biomass burning, soil and lightning), have shown an underestimation of SNOx by the algorithm of Yienger and Levy (1995). Nevertheless, to our knowledge no general improvements of this algorithm, besides suggested scalings of the total source magnitude, have yet been published. Here we present major improvements to the algorithm, which should help to optimize the representation of SNOx in atmospheric-chemistry global climate models, without modifying the underlying principals or mathematical equations. The changes include: (1) using a new landcover map, with twice the number of landcover classes, and using annually varying fertilizer application rates; (2) adopting a fraction of 1.0 % for the applied fertilizer lost as NO, based on our compilation of measurements; (3) using the volumetric soil moisture to distinguish between the wet and dry states; and (4) adjusting the emission factors to reproduce the measured emissions in our compilation (based on either their geometric or arithmetic mean values). These steps lead to increased global annual SNOx, and our total above canopy SNOx source of 8.6 Tg yr−1 (using the geometric mean) ends up being close to one of the satellite-based top-down approaches (8.9 Tg yr−1). The above canopy SNOx source using the arithmetic mean is 27.6 Tg yr−1, which is higher than all previous estimates, but compares better with a regional top-down study in eastern China. This suggests that both top-down and bottom-up approaches will be needed in future attempts to provide a better calculation of SNOx

Livestock Enterprise Budgets for Iowa--2002

This publication contains estimates of production costs for common livestock enterprises in Iowa. Estimates are intended to refl ect average or above-average levels of management using common types of technology. Input prices reflect expected average price levels during the year.

A DECISION MODEL TO ASSESS CATTLE FEEDING PRICE RISK

Traditional break-even/fed cattle price projections do not provide adequate risk information to feeders, investors, lenders, and other stakeholders interested in cattle feeding decisions. The objectives of this study were two-fold: 1) develop a spreadsheet model that could estimate the net income distribution surrounding a cattle placement decision based on historical errors of futures based price forecasts, and 2) determine whether information generated from the model can be used to improve placement and marketing decisions. To accomplish objective 1, model was developed that could estimate the income distribution around a pen of cattle under a cash speculating and short hedge pricing strategy. Distribution estimates were based on 7 alternative forecast horizons and were derived from historical forecast errors. To accomplish objective 2, decision rules were developed that allow the feeder to specify the maximum probability he/she is willing to risk losing a specified level of income. These decision rules were compared to random and naive decision rules by simulating the outcomes over 168 discrete six months feeding periods between 1987 and 2000. Risk averse decision rules were successful in signaling highly unprofitable feeding periods, but also filtered out highly profitable feeding periods.Livestock Production/Industries, Marketing,

High-temperature electronics

To meet the needs of the aerospace propulsion and space power communities, the high temperature electronics program at the Lewis Research Center is developing silicon carbide (SiC) as a high temperature semiconductor material. This program supports a major element of the Center's mission - to perform basic and developmental research aimed at improving aerospace propulsion systems. Research is focused on developing the crystal growth, characterization, and device fabrication technologies necessary to produce a family of SiC devices

The History of Social Work Education for Black People 1900-1930

The nature and extent of the contributions of Black people to social work education during the early twentieth century is the focus of this paper. The scope of this investigation includes: the identification of prominent Black social work educators; analysis of the curricula and the Atlanta School of Social Work and the Bishop Turtle School; and a description of the four basic approaches to social work training for Black people during this development phase of the social work profession

The Role of Sweet Potato Resistance in the Population Dynamics and Development of Meloidogyne Incognita.

Root-knot nematode populations endemic to Louisiana soils were identified to species and race. Meloidogyne incognita (Kofoid and White) Chitwood, (MI) accounted for 97 percent of the populations identified. Of the M. incognita species 55 percent were Race 1, 38 percent Race 3, and 7 percent Race 4. Meloidogyne javanica represented 3 percent of the populations studied. Populations were compared to the M. incognita used in the LSU sweet potato breeding program (MIS) for their virulence on the susceptible \u27Centennial\u27 and resistant \u27Jasper\u27, \u27Jewel\u27, and L4-73. The populations varied in virulence to the sweet potato cultivars with some populations being more virulent than the MIS population. Several populations appeared capable of overcoming resistance exhibited by the sweet potato cultivars. The life cycle of MIS was studied on \u27Centennial\u27, \u27Jasper\u27, \u27Jewel\u27, and W-51. Varietal resistance did not inhibit the initial rate of juvenile penetration, but did reduce the number of juveniles that reached maturity. Resistance reduced the number of juveniles that reached maturity; however, the rate of nematode development was more rapid in the resistant \u27Jewel\u27 than the other cultivars. The effect of MIS on the growth of \u27Centennial\u27 and \u27Jasper\u27 was studied in field plots artifically infested with initial population densities (Pi) ranging from 0-10,000 MIS eggs per 500 cc of soil. Population dynamics were similar on both cultivars; however, higher mid season counts were recorded from \u27Centennial\u27 than from \u27Jasper\u27. The highest Pi levels did not produce the highest mid season counts. Initial Pi levels had similar effects on the growth of \u27Centennial\u27 and \u27Jasper\u27 sweet potatoes. Pi levels were negatively correlated with marketable roots produced and root weight, but positively correlated with total cracked roots, percent cracked roots, and cracking severity ratings. \u27Jasper\u27 was able to tolerate significantly higher Pi levels with better yields and root quality than \u27Centennial\u27. The incidence of cracking of the fleshy root was apparent on both cultivars at low Pi levels

Reducing organic loading of anaerobic lagoons with high-rate anaerobic digestion : reactor performance and economic analysis

This research examined the potential of reducing dairy waste lagoon organic loading with high-rate anaerobic digestion (HRAD) systems operating at hydraulic retention times (HRT) of less than one day. An in-line approach was examined as a means of pre-treating the wastestream to reduce the lagoon organic load. An off-line approach was examined as a means to reduce the organic load within the anaerobic lagoon through the removal of volatile fatty acids. Two types of HRADs were tested, an anaerobic sequencing batch reactor (ASBR) and a downflow anaerobic filter (DFAF), both of which operated at 25 and 35° C. Initial plans were to use the HRADs for removal of organics by operating upstream of anaerobic lagoons. However, initial results of this approach were unsatisfactory, and it was suspected that the reactors were removing organic materials through settling rather than biodegradation. This possibility was tested by performing a chemical oxygen demand (COD) mass balance to determine if suspended solids settling was the main method of wastewater treatment. The mass balance demonstrated that 100% of the COD removed in the ASBRs, and 72% of the COD removed in the DFAFs, could be attributed to settling instead of biodegradation. The second experiment demonstrated that volatile fatty acids (VFA), mainly acetic (HAc), could be removed from the anaerobic lagoon if an HRAD was used in an off-line mode. Off-line operation would involve pulling HRAD influent from below the lagoon surface with the effluent being returned to the lagoon. At low loading rates (1.0 and 3.0 kg HAc m-3 d-1), both reactor types had treatment efficiencies greater than 30%. At the lowest loading there was no difference among the reactor types at the same temperature (P \u3e 0.33 for both temperatures). At the higher loading, there was a difference across reactor types at the same temperature (P \u3c 0.0001 for both temperatures). At a loading of 6.0 kg HAc -3 d-1 the ASBRs proved to be ineffective; whereas, the DFAJFs had removal efficiencies \u3e 70% for both temperatures. The DFAFs also provided \u3e 40% removal of HAc at loading rates of 24 kg HAc -3 d-1; thereby, suggesting that DFAFs are superior to ASBRs for removing accumulated VFAs at high loading rates. The high removal rates at the low HRTs allow for a smaller volumetric reactor and thereby a more feasible system. An economic model was developed to explore the feasibility of installing a DFAF system compared to expanding an existing anaerobic lagoon. The model computed the equivalent annualized annuity (EAA) of the two alternatives with a DFAF reactor operating at 0.8 kg HAc -3 d-1 and 2.4 kg HAc -3 d-1. The model was run for herd sizes ranging from 100 to 800 cows and overloads ranging from 10 to 100%. The results of the model suggests that for facilities with small herd sizes (\u3c 400 cows) and overloads less than 70%, expanding the lagoon is the preferred alternative. With large herd sizes (\u3e 400 cows) and overloads greater than 70%, the DFAF was suggested to be the preferred alternative