12 research outputs found

    Forest biomass diversion in the Sierra Nevada: Energy, economics and emissions

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    As an alternative to open pile burning, use of forest wastes from fuel hazard reduction projects at Blodgett Forest Research Station for electricity production was shown to produce energy and emission benefits: energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); based on measurements from a large pile burn, air emissions reductions were 98%-99% for PM2.5, CO (carbon monoxide), NMOC (nonmethane organic compounds), CH4 (methane) and BC (black carbon), and 20% for NOx and CO2-equivalent greenhouse gases. Due to transport challenges and delays, delivered cost was 70perbonedryton(BDT)−comprisedofcollectionandprocessing(70 per bone dry ton (BDT) - comprised of collection and processing (34/BDT) and transport (36/BDT)for79milesoneway−whichexceededthebiomassplantgatepriceof36/BDT) for 79 miles one way - which exceeded the biomass plant gate price of 45/BDT. Under typical conditions, the break-even haul distance would be approximately 30 miles one way, with a collection and processing cost of 30/BDTandatransportcostof30/BDT and a transport cost of 16/BDT. Revenue generated from monetization of the reductions in air emissions has the potential to make forest fuel reduction projects more economically viable

    Evidence and Ideology in Macroeconomics: The Case of Investment Cycles

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    The paper reports the principal findings of a long term research project on the description and explanation of business cycles. The research strongly confirmed the older view that business cycles have large systematic components that take the form of investment cycles. These quasi-periodic movements can be represented as low order, stochastic, dynamic processes with complex eigenvalues. Specifically, there is a fixed investment cycle of about 8 years and an inventory cycle of about 4 years. Maximum entropy spectral analysis was employed for the description of the cycles and continuous time econometrics for the explanatory models. The central explanatory mechanism is the second order accelerator, which incorporates adjustment costs both in relation to the capital stock and the rate of investment. By means of parametric resonance it was possible to show, both theoretically and empirically how cycles aggregate from the micro to the macro level. The same mathematical tool was also used to explain the international convergence of cycles. I argue that the theory of investment cycles was abandoned for ideological, not for evidential reasons. Methodological issues are also discussed

    Recent artificial selection in U.S. Jersey cattle impacts autozygosity levels of specific genomic regions

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    Background: Genome signatures of artificial selection in U.S. Jersey cattle were identified by examining changes in haplotype homozygosity for a resource population of animals born between 1953 and 2007. Genetic merit of this population changed dramatically during this period for a number of traits, especially milk yield. The intense selection underlying these changes was achieved through extensive use of artificial insemination (AI), which also increased consanguinity of the population to a few superior Jersey bulls. As a result, allele frequencies are shifted for many contemporary animals, and in numerous cases to a homozygous state for specific genomic regions. The goal of this study was to identify those selection signatures that occurred after extensive use of AI since the 1960, using analyses of shared haplotype segments or Runs of Homozygosity. When combined with animal birth year information, signatures of selection associated with economically important traits were identified and compared to results from an extended haplotype homozygosity analysis. Results: Overall, our results reveal that more recent selection increased autozygosity across the entire genome, but some specific regions increased more than others. A genome-wide scan identified more than 15 regions with a substantial change in autozygosity. Haplotypes found to be associated with increased milk, fat and protein yield in U.S. Jersey cattle also consistently increased in frequency. Conclusions: The analyses used in this study was able to detect directional selection over the last few decades when individual production records for Jersey animals were available

    Ultrasonic intensification as a tool for enhanced microbial biofuel yields

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    peer-reviewedUltrasonication has recently received attention as a novel bioprocessing tool for process intensification in many areas of downstream processing. Ultrasonic intensification (periodic ultrasonic treatment during the fermentation process) can result in a more effective homogenization of biomass and faster energy and mass transfer to biomass over short time periods which can result in enhanced microbial growth. Ultrasonic intensification can allow the rapid selective extraction of specific biomass components and can enhance product yields which can be of economic benefit. This review focuses on the role of ultrasonication in the extraction and yield enhancement of compounds from various microbial sources, specifically algal and cyanobacterial biomass with a focus on the production of biofuels. The operating principles associated with the process of ultrasonication and the influence of various operating conditions including ultrasonic frequency, power intensity, ultrasonic duration, reactor designs and kinetics applied for ultrasonic intensification are also described

    Forest biomass diversion in the Sierra Nevada: Energy, economics and emissions

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    As an alternative to open pile burning, use of forest wastes from fuel hazard reduction projects at Blodgett Forest Research Station for electricity production was shown to produce energy and emission benefits: energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); based on measurements from a large pile burn, air emissions reductions were 98%-99% for PM2.5, CO (carbon monoxide), NMOC (nonmethane organic compounds), CH4 (methane) and BC (black carbon), and 20% for NOx and CO2-equivalent greenhouse gases. Due to transport challenges and delays, delivered cost was 70perbonedryton(BDT)−comprisedofcollectionandprocessing(70 per bone dry ton (BDT) - comprised of collection and processing (34/BDT) and transport (36/BDT)for79milesoneway−whichexceededthebiomassplantgatepriceof36/BDT) for 79 miles one way - which exceeded the biomass plant gate price of 45/BDT. Under typical conditions, the break-even haul distance would be approximately 30 miles one way, with a collection and processing cost of 30/BDTandatransportcostof30/BDT and a transport cost of 16/BDT. Revenue generated from monetization of the reductions in air emissions has the potential to make forest fuel reduction projects more economically viable

    Forest biomass diversion in the Sierra Nevada: Energy, economics and emissions

    No full text
    As an alternative to open pile burning, use of forest wastes from fuel hazard reduction projects at Blodgett Forest Research Station for electricity production was shown to produce energy and emission benefits: energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); based on measurements from a large pile burn, air emissions reductions were 98%-99% for PM2.5, CO (carbon monoxide), NMOC (nonmethane organic compounds), CH4 (methane) and BC (black carbon), and 20% for NOx and CO2-equivalent greenhouse gases. Due to transport challenges and delays, delivered cost was 70perbonedryton(BDT)—comprisedofcollectionandprocessing(70 per bone dry ton (BDT) — comprised of collection and processing (34/BDT) and transport (36/BDT)for79milesoneway—whichexceededthebiomassplantgatepriceof36/BDT) for 79 miles one way— which exceeded the biomass plant gate price of 45/BDT. Under typical conditions, the break-even haul distance would be approximately 30 miles one way, with a collection and processing cost of 30/BDTandatransportcostof30/BDT and a transport cost of 16/BDT. Revenue generated from monetization of the reductions in air emissions has the potential to make forest fuel reduction projects more economically viable

    Assessing the role of federal community assistance programs to develop biomass utilization capacity in the western United States

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    As forest biomass utilization becomes cost effective to harvest, more areas at risk of catastrophic wildfire can be thinned of dense brush and small diameter trees. In an effort to increase biomass utilization, the USDA Forest Service granted more than $36 million in National Fire Plan-Economic Action Program funds in the western United States during fiscal years 2001 to 2003. Interviews with program coordinators and grant recipients were used to characterize the types of investment strategies used and to assess accomplishments relative to national fuels reduction objectives. Findings include a strong emphasis on grants leveraging other funding sources, coordination of resources to increase utilization capacity, and the need for technical assistance to facilitate project design and implementation. We conclude that community assistance programs may help to create the type of utilization capacity necessary to reduce hazardous fuels, but that sustained progress will depend on synergistic activities on multiple fronts and improved demonstration of program accomplishments.Biomass utilization Community assistance programs Hazardous fuel reduction Western United States
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