Bluebird-Flicker Conflict

Author Institution: Department of Biology, Kenyon College, Gambier, Ohio 4302

Differing Effects of Glycerin on Anaerobic Co-digestion of Mixed Substrates in Bench-Scale Assays and Sub Pilot-Scale Reactors

Bench-scale methods such as Biochemical Methane Potential (BMP) assays and Anaerobic Toxicity Assays (ATAs) are useful tools in evaluating potential feedstocks for anaerobic digestion. The BMP method provides a preliminary indication of substrate biodegradability and methane production, while the ATAs provide an indication of substrate toxicity to anaerobic microbial consortia. Previous research using small (\u3c20 \u3eL) reactors indicated that co-digestion of manures with small amounts of glycerin (ca. 1 – 2 %) can double methane production, but toxicity can result if glycerin exceeds 2% (volumetric basis). This paper investigated the relationship between bench-scale methods (BMPs and ATAs) and sub pilot-scale digester results, using glycerin as a test substrate mixed with a baseline feedstock (beef manure, corn processing wastewater, lagoon liquid, and short-fiber cardboard). The batch-fed, stirred ATAs indicated that glycerin was toxic to methane production at all inclusion levels. The batch-fed, stirred BMPs indicated no significant difference between methane production in the 0.0%to 4.0% addition levels; however at 8.0% addition, methane production tripled. The continuously fed, non-stirred, plug-flow sub pilot-scale reactors indicated toxicity effects in the 2.0% and 4.0% glycerin mixtures and no difference from the control in the 1.0% glycerin mixture. These results demonstrate the variations in scale performance of glycerin as a co-substrate and identify some serious challenges in extrapolating bench-scale assays to large-scale performance of mixed-waste anaerobic digestion systems

Effect of Ammonia Soaking Pretreatment and Enzyme Addition on Biochemical Methane Potential of Switchgrass

This article presents the biochemical methane potential (BMP) results from the anaerobic digestion (AD) of switchgrass. Triplicate BMP assays were performed on: untreated switchgrass, aqueous ammonia soaking (AAS) pretreated switchgrass (soaked in 29.5% reagent-grade aqueous ammonia at 5 L kg-1 switchgrass for 5 d), and AAS-pretreated switchgrass plus cellulytic enzymes at 12.5, 25, 62.5, and 125 filter paper units (FPU) enzyme g-1 volatile solids (VS). Biogas production and biogas methane content were measured daily in all treatments for 21 d. Both biogas and corrected methane production varied significantly among treatments, especially during the first 7 d of the BMP period. Total methane production at 21 d was corrected for enzyme degradation, and methane yields ranged from 0.15 to 0.36 m3 CH4 kg-1 VS. We compared the corrected energy yield of biogas from switchgrass to prior reports of the energy yield of ethanol from switchgrass via simultaneous saccharification and fermentation (SSF). The AD of AAS-pretreated switchgrass at the highest enzyme loading rates resulted in a 120% increase in energy extracted as compared to AAS-pretreated switchgrass converted to ethanol via SSF. Overall, the addition of enzymes to AAS-pretreated switchgrass greatly accelerated the rate of methane production over the untreated switchgrass and AAS-pretreated switchgrass without enzymes. However, the process economics are not clear, and additional work is needed to determine whether pretreating switchgrass with aqueous ammonia and/or enzymes before AD is economically advantageous

Approaches for Selecting Anaerobic Digestion Co-Substrates for a Full-Scale Beef Manure Digester Using Biochemical Methane Potentials and Anaerobic Texicity Assays

Design and construction of full-scale anaerobic digesters that co-digest manure with various materials requires analysis of each substrate. Substrate combinations should be analyzed through a scale up procedure in which substrates are characterized, and then evaluated using biochemical methane potential assays (BMPs) and anaerobic toxicity assays (ATAs). The BMPs provide a preliminary indication of the biodegradability of a substrate and of its potential to produce methane via anaerobic digestion, while ATAs determine the degree to which a particular substrate inhibits methane production. Mixture combinations that perform well in BMPs and ATAs should be tested in laboratory-scale anaerobic digesters. Once proven in lab-scale reactors for at least three hydraulic retention times, the best mixture should be tested in a pilot-scale reactor. This paper focuses on the first steps in this process using BMPs and ATAs results to select mixtures for laboratory-scale digester testing. The baseline feedstock was beef manure obtained from concrete feedlot pens (open and covered) in eastern Iowa. Various bedding materials were available, including oat hulls, corn stover, and wood shavings. To provide additional energy production, industrial byproducts from cardboard manufacturing, enzyme production, and corn and soybean processing were also potential substrates. Substrates were characterized for TS, VS, COD, pH, alkalinity, and ammonia. Then BMPs were completed on all substrates and ATAs were performed as needed. The results reported here were used to develop mixtures for use in laboratory-scale anaerobic digester testing

Comparison of Methane Production from Bench- and Sub Pilot-Scale Anaerobic Digesters

Design and construction of full-scale anaerobic digesters that co-digest manure with other substrates, such as food processing wastes, is challenging because of the large number of potential mixtures that can be fed to the digester. In this work we examine the relationship between results from bench-scale methods such as biochemical methane potential assays (BMPs) and sub pilot-scale reactors. The baseline feedstock for this study was beef manure from concrete feedlot pens (open and covered) in eastern Iowa. Additional co-digestion substrates tested were short-fiber cardboard, corn processing wastewater, enzyme processing wastewater and lagoon liquid. Substrates were characterized for total solids (TS), volatile solids (VS), chemical oxygen demand (COD), pH, alkalinity, and ammonia, after which BMPs were conducted on all substrates. Based on the BMP and anaerobic toxicity assay (ATA) results, a mixture was created and evaluated using BMPs and tested in 100-L sub pilot-scale reactors. This study showed that results from BMPs of feedstock co-digestion mixtures accurately estimated the range of methane produced from three 100-L, plug flow reactors

Emotion regulation in psychopathy

Emotion processing is known to be impaired in psychopathy, but less is known about the cognitive mechanisms that drive this. Our study examined experiencing and suppression of emotion processing in psychopathy. Participants, violent offenders with varying levels of psychopathy, viewed positive and negative images under conditions of passive viewing, experiencing and suppressing. Higher scoring psychopathics were more cardiovascularly responsive when processing negative information than positive, possibly reflecting an anomalously rewarding aspect of processing normally unpleasant material. When required to experience emotional response, by ‘getting into the feeling’ of the emotion conveyed by a negative image, higher factor 1 psychopathic individuals showed reduced responsiveness, suggesting that they were less able to do this. These data, together with the absence of corresponding differences in subjective self-report might be used to inform clinical strategies for normalising emotion processing in psychopathic offenders to improve treatment outcome, and reduce risk amongst this client group

High frequency oscillator comprising cointegrated thin film resonator and active device

A cointegrated high frequency oscillator including a thin film resonator and activedevices formed on the same semiconductor substrate and by a process which is compatible with formation of both the thin film resonator and the active devices. The processes utilized in formation of the thin film resonator are adapted to microelectronic processing techniques such that the steps of formation of the active devices and the thin film resonator can be intermixed to the degree necessary to allow, for example, the metallization layers to serve as elements both of the active devices and the thin film resonator

Dynamics and Deposition of Sediment-Bearing Multi- Pulsed Flows and Geological Implication

Copyright © 2019, SEPM (Society for Sedimentary Geology) Previous studies on dilute, multi-pulsed, subaqueous saline flows have demonstrated that pulses will inevitably advect forwards to merge with the flow front. On the assumption that pulse merging occurs in natural-scale turbidity currents, it was suggested that multi-pulsed turbidites that display vertical cycles of coarsening and fining would transition laterally to single-pulsed, normally graded turbidites beyond the point of pulse merging. In this study, experiments of dilute, single- and multi-pulsed sediment-bearing flows (turbidity currents) are conducted to test the linkages between downstream flow evolution and associated deposit structure. Experimental data confirm that pulse merging occurs in laboratory-scale turbidity currents. However, only a weak correspondence was seen between longitudinal variations in the internal flow dynamics and the vertical structure of deposits; multi-pulsed deposits were documented, but transitioned to single-pulsed deposits before the pulse merging point. This early transition is attributed to rapid sedimentation-related depletion of the coarser-grained suspended fraction in the laboratory setting, whose absence may have prevented the distal development of multi-pulsed deposits; this factor complicates estimation of the transition point in natural-scale turbidite systems