The Impact of Spatial Heterogeneity in Land Use Practices and Aquifer Characteristics on Groundwater Conservation Policy Cost

Estimation of agricultural policy cost for a given level of groundwater conservation requires the establishment of an accurate baseline condition. This is especially critical when the benefits and cost of any conservation program are generally estimated relative to the status quo policy or baseline situation. An inaccurate baseline estimate will lead to poor estimates of potential water conservation savings and agricultural policy cost. Over a 60-year planning horizon per acre net present value is as much as 29.8% higher for a study area when aquifer characteristics are assumed to be homogenous and set to their average area value than when the heterogeneity in aquifer characteristics is explicitly modeled.Aquifer Modeling, Economics, Resource /Energy Economics and Policy,

Nonlocalized modulation of periodic reaction diffusion waves: The Whitham equation

In a companion paper, we established nonlinear stability with detailed diffusive rates of decay of spectrally stable periodic traveling-wave solutions of reaction diffusion systems under small perturbations consisting of a nonlocalized modulation plus a localized perturbation. Here, we determine time-asymptotic behavior under such perturbations, showing that solutions consist to leading order of a modulation whose parameter evolution is governed by an associated Whitham averaged equation

771-3 Direct Characterization of F1ecalnide Binding Rates from Use-Dependent Conduction Delay In Canine Purkinje Fibers

To quantitatively characterize flecainide-induced channel blockade from usedependent conduction delay (CD), 12 canine purkinje fibers were studied using a dual microelectrode technique. During 60 sec of pacing at interstimulus intervals (ISI) of 1.25–0.4 sec with 2μM flecainide (FLEC), incremental CD followed a monoexponential time course, the rates of which were linearly related to the interpulse recovery interval (tr=ISI — action potential duration). Steady state block was an exponential function of the recovery rates. Use-dependent block derived from incremental CD and decremental squared conduction velocity (θ2) was characterized by the forward (k) and reverse (I) rate constants for the activated (a) and resting (r) states:ka (× 106) (mol-1 s-1)la (s-1)kr (× 102) (mol-1 s-1)Ir (s-1)CD7.0±2.612.0±4.40.6±1.74.01±1.63θ210.0±3.414.7±2.52.8±5.73.66±1.40Vmax(prox)6.8±2.315.9±5.05.1±10.34.22±1.11These rates reflect marked open state Na+ channel block and closed channel trapping at resting membrane potentials with FLEC. The addition of 1μM isoproterenol (ISO) to FLEC-superfused fibers reversed the FLEC-induced reduction of θ2 from 1.79±0.7 to 1.89±0.89 (m/s)2 (p=0.017) without changing V˙max. The rate constants for FLEC binding and unbinding were not altered by ISO. Thus FLEC's apparent binding rates can be quantified from its use-{jependent effects on conduction. Both ISO's selective reversal of FLEC effect on θ2 but not V˙max and the absence of changes in the rate constants suggest that the modulation of FLEC effect is due to an alteration in passive membrane properties. These characterizations will facilitate subsequent comparisons of FLEC interactions in pathologic and hyperadrenergic states in vivo

The Australian Farm Business Management Network: Industry, Education, Consultancy and Research Coming Together

Under the sponsorship of the University of Sydney, on 5-6th December 2002 the future of farm management in Australia was discussed. The fundamental conclusion achieved by key primary industry representatives, corporate executives, academics, consultants and researchers is that farm management will have a more significant role to play in the future than previously in servicing the primary sector. The idea of farm management as a profession was proposed. Its basis would be business management supported by farming systems and technology, and using an holistic approach to action (i.e. finance, people and environment). The new profession of Farm Business Management would seek to influence education, research, consultancy and extension in Australia. Interested parties participating of the 2002 National Farm Management Workshop came away with the idea of championing a consultative network, constituted by interested institutions and interested individuals, as a first step in the process of nurturing the future development of farm business management. By integrating farmers and academics with corporate executives, consultants and researchers the objective is to behave as a consultative group. This group will influence educational models, implement consultancy and research strategies, and network in social and professional terms. Moreover, this network will provide a systematic opportunity for the channelling of farm business management and farming systems related information at different levels for education, extension and scientific purposes. This network is called the Australian Farm Business Management Network (AFBMnetwork).Institutional and Behavioral Economics,

The impact of nitrogen contamination and river modification on a Mississippi River floodplain lake

Anthropogenic nitrogen contamination has increased in ecosystems around the world (frequently termed the “nitrogen cascade”). Coke production for steel manufacturing is often overlooked as a source of nitrogen to natural ecosystems. We examined sediment cores from a Horseshoe Lake, a floodplain lake located just East of St. Louis Missouri (USA) to test whether a coking plant effluent could be traced using stable isotopes of nitrogen and diatom microfossils. The distribution of δ15N values in surface sediment samples from the lake shows the highest values near the coking plant effluent. Analysis stable isotopes of nitrogen from sediment cores using a binary mixing model showed three sources of nitrogen since 1688 CE. The first source (active between 1688 and 1920 CE) had a calculated δ15N value of -.8±.4‰. After 1920 a second source with a δ15N of 20.2±2.0 ‰ became active. The diatom microfossil assemblages present from 1688 CE to the late 1800’s are dominated by the planktonic species Aulacoseira granulata and periphytic and benthic genera Gomphonema, Cocconeis, and Lyrella. After the late 1800’s the diatom assemblages are dominated by Staurosira species indicating a shift of species from high flow riverine environments to epipelic species from a lake environment. Our results show how stable isotopes of nitrogen can be used to track nitrogen inputs from industrial sources. They suggest that the high nitrogen input has not been a major source of eutrophication in the lake

Performance Testing and Analysis of Synchronous Reluctance Motor Utilizing Dual-phase Magnetic Material

While interior permanent magnet (1PM) machines have been considered the state-of-the art for traction motors, synchronous reluctance (SynRel) motors with advanced materials can provide a competitive alternative. 1PM machines typically utilize Neodymium 1ron Boron (NdFeB) permanent magnets, which pose an issue in terms of price, sustainability, demagnetization at higher operating temperatures, and uncontrolled generation. On the other hand, SynRel machines do not contain any magnets and are free from these issues. However, the absence of magnets as well the presence of bridges and centerposts limit the flux-weakening capability of a SynRel machine and limit the achievable constant power speed ratio (CPSR) without having to significantly oversize the machine and/or the power converter. 1n this paper, a new material referred to as the dual-phase magnetic material where nonmagnetic regions can be selectively introduced within each lamination will be evaluated for SynRel designs. The dual-phase feature of this material enables non-magnetic bridges and posts, eliminating one of the key limitations of the SynRel designs in terms of torque density and flux-weakening. This paper will present, the design, analysis and test results of an advanced proof-of-concept SynRel design utilizing dual-phase material with traction applications as the ultimate target application

Abort Trigger False Positive and False Negative Analysis Methodology for Threshold-Based Abort Detection

This paper describes a quantitative methodology for bounding the false positive (FP) and false negative (FN) probabilities associated with a human-rated launch vehicle abort trigger (AT) that includes sensor data qualification (SDQ). In this context, an AT is a hardware and software mechanism designed to detect the existence of a specific abort condition. Also, SDQ is an algorithmic approach used to identify sensor data suspected of being corrupt so that suspect data does not adversely affect an AT's detection capability. The FP and FN methodologies presented here were developed to support estimation of the probabilities of loss of crew and loss of mission for the Space Launch System (SLS) which is being developed by the National Aeronautics and Space Administration (NASA). The paper provides a brief overview of system health management as being an extension of control theory; and describes how ATs and the calculation of FP and FN probabilities relate to this theory. The discussion leads to a detailed presentation of the FP and FN methodology and an example showing how the FP and FN calculations are performed. This detailed presentation includes a methodology for calculating the change in FP and FN probabilities that result from including SDQ in the AT architecture. To avoid proprietary and sensitive data issues, the example incorporates a mixture of open literature and fictitious reliability data. Results presented in the paper demonstrate the effectiveness of the approach in providing quantitative estimates that bound the probability of a FP or FN abort determination

Ferrimicrobium acidiphilum gen. nov., sp. nov. and Ferrithrix thermotolerans gen. nov., sp. nov.: heterotrophic, iron-oxidizing, extremely acidophilic actinobacteria

Two novel extremely acidophilic, iron-oxidizing actinobacteria were isolated, one from a mine site in North Wales, UK (isolate T23T), and the other from a geothermal site in Yellowstone National Park, Wyoming, USA (Y005T). These new actinobacteria belong to the subclass Acidimicrobidae, and in contrast to the only other classified member of the subclass (Acidimicrobium ferrooxidans), both isolates were obligate heterotrophs. The mine site isolate was mesophilic and grew as small rods, while the Yellowstone isolate was a moderate thermophile and grew as long filaments, forming macroscopic flocs in liquid media. Both isolates accelerated the oxidative dissolution of pyrite in yeast extract-amended cultures, but neither was able to oxidize reduced forms of sulfur. Ferrous iron oxidation enhanced growth yields of the novel mesophilic actinobacterium T23T, though this was not confirmed for the Yellowstone isolate. Both isolates catalysed the dissimilatory reduction of ferric iron, using glycerol as electron donor, in oxygen-free medium. Based on comparative analyses of base compositions of their chromosomal DNA and of their 16S rRNA gene sequences, the isolates are both distinct from each other and from Acidimicrobium ferrooxidans, and are representatives of two novel genera. The names Ferrimicrobium acidiphilum gen. nov., sp. nov. and Ferrithrix thermotolerans gen. nov., sp. nov. are proposed for the mesophilic and moderately thermophilic isolates, respectively, with the respective type strains T23T (5DSM 19497T5ATCC BAA-1647T) and Y005T (5DSM 19514T5ATCC BAA-1645T).info:eu-repo/semantics/publishedVersio

Role of pure and mixed cultures of gram-positive eubacteria in mineral leaching

Research on the biooxidation of sulfidic minerals has tended to be heavily biased towards Gram-negative bacteria, such as Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans. Currently, just three species of mineral-oxidising Gram-positive bacteria are recognised: Sulfobacillus thermosulfidooxidans, Sulfobacillus acidophilus and Acidimicrobium (Am.) ferrooxidans, all of which are thermotolerant prokaryotes. We have isolated and characterised a number of phylogenetically distinct Gram-positive ironmetabolising bacteria, including mesophilic and moderately thermophilic strains. Mesophilic isolates include (i) novel Sulfobacillus spp., some of which are the more acidophilic than all known iron-oxidising bacteria, (ii) "Ferrimicrobium acidiphilum", an actinobacterium most closely related to Am. ferrooxidans, and (iii) a group of low GC Gram-positives which appear to represent a novel genus. Moderately thermophilic isolates include a novel Sulfobacillus sp., an Alicyclobacillus spp. that, in contrast to currently recognised species, grows anaerobically by reduction of ferric iron and thrives in mineral leaching environments, and a new genus/species of iron- and sulfur-oxidising bacterium with the proposed name "Caldibacillus ferrivorus". These novel prokaryotes exhibited varying degrees of mineral leaching efficiencies, with the mesophilic Sulfobacillus spp. being particularly adept at solubilising pyrite at very low (<1) pH values. All novel Gram-positive isolates catalysed the oxidative dissolution of pyrite at lower redox potentials than Gram-negative mesophiles. Mixed cultures of Gram-positive bacteria, either with other Gram-positives or with Gram-negative bacteria, were often more effective mineral-leaching systems than corresponding pure cultures.info:eu-repo/semantics/publishedVersio