8,032 research outputs found

    Assessing Ohio's Biomass Resources for Energy Potential Using GIS

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    This recently completed AEDE study funded by Ohio DOD involves a geo-referenced inventory by county of Ohio biomass resources for energy. Categories include forest and crop residues, livestock manure, municipal solid waste and food processing waste. This is an update and expansion of an earlier (1982) inventory of biomass by Hitzhusen et al. It also disaggregates and expands a study by Walsh et al. in 2000 which ranked Ohio 11th among the 50 states in total biomass availability. By estimating and geo-referencing the sustainable quantities of various categories of biomass for energy by county, it is possible to identify the spatial concentrations of various biomass renewable energy feedstocks that may be economically viable for various processes for conversion. These conversion processes in turn have implications for environmental improvement and reduced dependence on foreign oil imports. A better understanding of the technical and economic pros and cons of the most promising conversion processes will be required along with further data collection and refinements of this inventory (particularly the food processing waste subset) before detailed policy recommendations can be made. However, this study is hopefully a good start toward that goal and should provide direction and focus for future analysis and recommendations for a more renewable and sustainable energy and environmental future for Ohio.Availability, Biomass energy, Crop residues, Livestock manure, Wood wastes, Municipal solid wastes.

    A study of the ozonolysis of isoprene in a cryogenic buffer gas cell by high resolution microwave spectroscopy

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    We have developed a method to quantify reaction product ratios using high resolution microwave spectroscopy in a cryogenic buffer gas cell. We demonstrate the power of this method with the study of the ozonolysis of isoprene, CH2=C(CH3)-CH=CH2, the most abundant, non-methane hydrocarbon emitted into the atmosphere by vegetation. Isoprene is an asymmetric diene, and reacts with O3 at the 1,2 position to produce methyl vinyl ketone (MVK), formaldehyde, and a pair of carbonyl oxides: [CH3CO-CH=CH2 + CH2=OO] + [CH2=O + CH3COO-CH=CH2]. Alternatively, O3 could attack at the 3,4 position to produce methacrolein (MACR), formaldehyde, and two carbonyl oxides [CH2=C(CH3)-CHO + CH2=OO] + [CH2=O + CH2=C(CH3)-CHOO]. Purified O3 and isoprene were mixed for approximately 10 seconds under dilute (1.5-4% in argon) continuous flow conditions in an alumina tube held at 298 K and 5 Torr. Products exiting the tube were rapidly slowed and cooled within the buffer gas cell by collisions with cryogenic (4-7 K) He. High resolution chirped pulse microwave detection between 12 and 26 GHz was used to achieve highly sensitive (ppb scale), isomer-specific product quantification. We observed a ratio of MACR to MVK of 2.1 +/- 0.4 under 1:1 ozone to isoprene conditions and 2.1 +/- 0.2 under 2:1 ozone to isoprene conditions, a finding which is consistent with previous experimental results. Additionally, we discuss relative quantities of formic acid (HCOOH), an isomer of CH2=OO, and formaldehyde (CH2=O) under varying experimental conditions, and characterize the spectroscopic parameters of the singly-substituted 13C trans-isoprene and 13C anti-periplanar-methacrolein species. This work has the potential to be extended towards a complete branching ratio analysis, as well towards the ability to isolate, identify, and quantify new reactive intermediates in the ozonolysis of alkenes

    System characterization of a magnetically suspended flywheel

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    The purpose of flywheel energy storage is to provide a means to save energy during times when the satellite is in sunlight, and then return the energy during the time when the satellite is in darkness. Typically, an energy storage device operates cyclically, where for satellites in Low Earth Orbit (LEO) the typical period is 60 minutes of sunlight followed by 30 minutes of darkness. If a lifetime of 17 years is required the energy storage system must be capable of sustaining approximately 100,000 cycles. The recent developments at the University of Maryland and how these progressions apply to a 500 Watt-hour magnetically suspended flywheel stack energy storage system are covered. The work includes hardware testing results from a stack flywheel energy storage system, improvements in the area of non-contacting displacement transducers, and performance enhancements of magnetic bearings. The experimental results show that a stack flywheel energy storage system is a feasible technology

    Price Determinants in Top Quality E-Auctioned Specialty Coffees

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    The US specialty coffee industry has grown from 1billionin1990to1 billion in 1990 to 11 billion in 2006 and is expected to continue to grow into the foreseeable future. This growth particularly depends on prices coordinating the specialty coffee supply chain through two-way information exchange between roasters and producers. We analyze the determinants of specialty coffee prices by estimating a hedonic price function for specialty Central and South American coffees traded at e-auctions. We hypothesize that since specialty coffee is a differentiated product, prices will be determined by both sensory and reputation attributes. The results show that prices are influenced by the quality rating, which is a sensory variable, and by the quality rankings established in the cupping competition previous to the auction, the country of origin and the coffee variety, which are reputation variables. In addition, the macro variables, harvest year and commodity price were found to be significant.Specialty coffee, hedonic price analysis, differentiated food pricing, sensory attributes, reputation attributes, Demand and Price Analysis,

    Cosmic Chemical Evolution

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    Numerical simulations of standard cosmological scenarios have now reached the degree of sophistication required to provide tentative answers to the fundamental question: Where and when were the heavy elements formed? Averaging globally, these simulations give a metallicity that increases from 1% of the solar value at z=3z=3 to 20% at present. This conclusion is, in fact, misleading, as it masks the very strong dependency of metallicity on local density. At every epoch higher density regions have much higher metallicity than lower density regions. Moreover, the highest density regions quickly approach near solar metallicity and then saturate, while more typical regions slowly catch up. These results are much more consistent with observational data than the simpler picture (adopted by many) of gradual, quasi-uniform increase of metallicity with time.Comment: ApJ(Letters) in press, 15 latex pages and 4 figure

    Patients with Essential thrombocythaemia have an increased prevalence of antiphospholipid antibodies which may be associated with thrombosis

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    A significant proportion of patients with Essential Thrombocythaemia (ET) have thrombotic complications which have an important impact upon the quality, and duration of their life. We performed a retrospective cross sectional study of the prevalence of antiphospholipid antibodies (APA) in 68 ET patients. Compared to 200 elderly controls (> 50 years) there was a significant increase in anticardiolipin IgM (p < 0.0001) and anti β2 glycoprotein I (anti-β2GPI) IgM (p < 0.0001) antibodies in ET. Thrombosis occurred in 10/20 with APA and 12/48 without, p = 0.04, relative risk 2.0 (95% confidence intervals 1.03-3.86); these patients did not differ in terms of other clinical features. The prevalence of thrombosis in patients with dual APA (6/7) was significant when compared to those with single APA (p = 0.02) and the remaining patients (p < 0.0002). Also anti-β2GPI IgM antibodies either alone, or in combination with another APA, were associated with thrombosis (p = 0.02). These results suggest that the prevalence of APA in ET and their influence upon thrombotic risk merit investigation in a larger study

    Theoretical Modeling of the High Redshift Galaxy Population

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    We review theoretical approaches to the study of galaxy formation, with emphasis on the role of hydrodynamic simulations in modeling the high redshift galaxy population. We present new predictions for the abundance of star-forming galaxies in the Lambda + cold dark matter model (Omega_m=0.4, Omega_L=0.6), combining results from several simulations to probe a wide range of redshift. At a threshold density of one object per arcmin^2 per unit z, these simulations predict galaxies with star formation rates of 2 msun/yr (z=10), 5 msun/yr (z=8), 20 msun/yr (z=6), 70-100 msun/yr (z=4-2), and 30 msun/yr (z=0.5). For galaxies selected at a fixed comoving space density n=0.003 h^3 Mpc^{-3], a (50 Mpc/h)^3 simulation predicts a galaxy correlation function (r/5 Mpc/h)^{-1.8} in comoving coordinates, essentially independent of redshift from z=4 to z=0.5. Different cosmological models predict global histories of star formation that reflect their overall histories of mass clustering, but robust numerical predictions of the comoving space density of star formation are difficult because the simulations miss the contribution from galaxies below their resolution limit. The LCDM model appears to predict a star formation history with roughly the shape inferred from observations, but it produces too many stars at low redshift, predicting Omega_* ~ 0.015 at z=0. We conclude with a brief discussion of this discrepancy and three others that suggest gaps in our current theory of galaxy formation: small disks, steep central halo profiles, and an excess of low mass dark halos. While these problems could fade as the simulations or observations improve, they could also guide us towards a new understanding of galactic scale star formation, the spectrum of primordial fluctuations, or the nature of dark matter.Comment: 12 pages, 3 figs. To be published in "Photometric Redshifts and High Redshift Galaxies", eds. R. Weymann, L. Storrie-Lombardi, M. Sawicki & R. Brunner, (San Francisco: ASP Conference Series
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