Design and Operational Modifications to Model IV FCCUs to Improve Dynamic Performance

Model IV Fluid Catalytic Cracking Units (FCCUs) differ from other cracking units in that model IV FCCUs do not have slide valves in the catalyst circulation lines to enable direct control of catalyst circulation rate through the unit. Reducing fluctuations in catalyst circulation rate is found to significantly improve closed loop performance of the FCCU. Some design and operational modifications that can be made to model IV FCCUs to improve closed loop performance at the regulatory level based on this insight are modeled and compared. Closed loop performance of a model IV FCCU operated with the weir and standpipe always flooded is examined. The achievable performance is significantly better than that of the standard model IV FCCU. The closed loop performance of the model IV FCCU modified to incorporate slide valves in the catalyst circulation lines is also examined. The performance of the FCCU with slide valves is better than the performance achievable by the FCCU with the weir flooded. It is found that model IV FCCUs are ill-conditioned owing to the use of the weir and standpipe arrangement in the regenerator section. Both the operational and design modifications studied reduce plant ill-conditioning appreciably

Priority Water Issues in the Pacific Northwest

We developed and conducted a region-wide survey to collect base line information documenting public awareness, attitudes, and priorities about water issues in the Pacific Northwest. The vast majority (over 90%) of survey respondents considered clean drinking water, clean groundwater, and clean rivers very or extremely important issues. Over two-thirds of survey respondents considered having enough water for economic development, prevention of salmon extinction, wetland protection, watershed restoration, water for power generation, and water for agriculture to be high priority issues. The results from this survey will be used to target our regional programming efforts over the next 5 years

Physics of windblown particles

A laboratory facility proposed for the Space Station to investigate fundamental aspects of windblown particles is described. The experiments would take advantage of the environment afforded in earth orbit and would be an extension of research currently being conducted on the geology and physics of windblown sediments on earth, Mars, and Venus. Aeolian (wind) processes are reviewed in the planetary context, the scientific rational is given for specific experiments to be conducted, the experiment apparatus (the Carousel Wind Tunnel, or CWT) is described, and a plan presented for implementing the proposed research program

Review of In-Place Treatment Techniques for Contaminated Surface Soils - Volume 2: Background Information for In Situ Treatment

This second volume of a two volume manual on in-place treatment of hazardous waste contaminated soil supports the treatment methodology described in Volume 1 (EPA- ). The information presented on monitoring to determine treatment effectiveness, characterization and evaluation of the behavior and fate of hazardous constituents in soil/waste systems, and properties (including adsorption, degradation, and volatilization parameters) for various compounds is intended to help the manual user in making more complex decisions and in selecting analyses concerning site, soil, and waste interactions. This report was submitted in partial fulfillment of Contract No. 68-03-3113 by Utah State University under the sponsorship of the U.S. Environmental Protection Agency. The report covers the period December 1982 to December 1984 and work was completed as of January 1984

Evaluation of Leaf Spot Resistance in Wild \u3ci\u3eArachis\u3c/i\u3e Species of Section \u3ci\u3eArachis\u3c/i\u3e

Wild diploid Arachis species are potential sources of resistance to early (ELS) and late (LLS) leaf spot diseases caused by Passalora arachidicola (syn. Cercospora arachidicola Hori), and Nothopassalora personata (syn. Cercosporidium personatum (Berk. & Curt.) Deighton), respectively. Within section Arachis, limited information is available on the extent of genetic variation for resistance to these fungal pathogens. A collection of 78 accessions representing 15 wild species of Arachis section Arachis from the U.S peanut germplasm collection was evaluated for resistance to leaf spots. Screening was conducted under field (natural inoculum) conditions in Dawson, Georgia, during 2017 and 2018. Accessions differed significantly (P , 0.01) for all three disease variables evaluated, which included final defoliation rating, ELS lesion counts, and LLS lesion counts. Relatively high levels of resistance were identified for both diseases, with LLS being the predominant pathogen during the two years of evaluation. This research documents new sources of resistance to leaf spot diseases selected from an environment with high inoculum pressure. The presence of ELS and LLS enabled the selection of resistant germplasm for further introgression and pre-breeding

Using a hybrid neural system to reveal regulation of neuronal network activity by an intrinsic current

©2004 Society for NeuroscienceThe electronic version of this article is the complete one and can be found online at: http://www.jneurosci.org/content/24/23/5427.abstractDOI: 10.1523/JNEUROSCI.4449-03.2004The generation of rhythmic patterns by neuronal networks is a complex phenomenon, relying on the interaction of numerous intrinsic and synaptic currents, as well as modulatory agents. To investigate the functional contribution of an individual ionic current to rhythmic pattern generation in a network, we constructed a hybrid system composed of a silicon model neuron and a heart interneuron from the heartbeat timing network of the medicinal leech. When the model neuron and a heart interneuron are connected by inhibitory synapses, they produce rhythmic activity similar to that observed in the heartbeat network. We focused our studies on investigating the functional role of the hyperpolarization-activated inward current (I[subscript h] ) on the rhythmic bursts produced by the network. By introducing changes in both the model and the heart interneuron, we showed that I[subscript h] determines both the period of rhythmic bursts and the balance of activity between the two sides of the network, because the amount and the activation/deactivation time constant of I[subscript h] determines the length of time that a neuron spends in the inhibited phase of its burst cycle. Moreover, we demonstrated that the model neuron is an effective replacement for a heart interneuron and that changes made in the model can accurately mimic similar changes made in the living system. Finally, we used a previously developed mathematical model (Hill et al. 2001) of two mutually inhibitory interneurons to corroborate these findings. Our results demonstrated that this hybrid system technique is advantageous for investigating neuronal properties that are inaccessible with traditional techniques

Deflated GMRES for Systems with Multiple Shifts and Multiple Right-Hand Sides

We consider solution of multiply shifted systems of nonsymmetric linear equations, possibly also with multiple right-hand sides. First, for a single right-hand side, the matrix is shifted by several multiples of the identity. Such problems arise in a number of applications, including lattice quantum chromodynamics where the matrices are complex and non-Hermitian. Some Krylov iterative methods such as GMRES and BiCGStab have been used to solve multiply shifted systems for about the cost of solving just one system. Restarted GMRES can be improved by deflating eigenvalues for matrices that have a few small eigenvalues. We show that a particular deflated method, GMRES-DR, can be applied to multiply shifted systems. In quantum chromodynamics, it is common to have multiple right-hand sides with multiple shifts for each right-hand side. We develop a method that efficiently solves the multiple right-hand sides by using a deflated version of GMRES and yet keeps costs for all of the multiply shifted systems close to those for one shift. An example is given showing this can be extremely effective with a quantum chromodynamics matrix.Comment: 19 pages, 9 figure

Studies on Viruses in Water

A new procedure for the detection of viral antigens in fecal material was developed. The test is performed by first diluting a fecal sample with phosphate buffered saline to give a liquid consistency. The pH is then adjusted to 8.5-9.0 and the solids are allowed to settle for five minutes. Supernatant fluid from above the fecal sediment is placed on the upper surface of a well of an inverted Immulon microtiter plate and incubated for one hour at 37 degrees C to allow virus to adsorb to the plastic. The Immulon plate is then washed three times with a Tween 20 solution and dried. Adsorbed virus is stained with fluorescein labled antiviral antibody containing Evan\u27s Blue dye. The stained preparations are examined by epi-fluorescence microsopy for the presence of viral aggregates and virus-containing cellular membranes. The test is applied in a continuous water monitoring procedure that can be used to upplement methods in which infectious viruses are isolated from water. In another study a protamine sulfate procedure for concentrating and an immunofluorescent cell procedure for assaying infectious virus (IV, reovirus that is infectious without proteolytic enzyme treatment), and potentially infectious virus (PIV, enzyme enhanceable reovirus) from polluted waters have been developed. The presence of PIV inthe environment had not previously been investigated. In following these procedures, protamine sulfate concentratiosn of 0.005 percent for the first precipitation of the sample, and 0.0025 percent for the second were used. With these protamine concentrations and 0.25 percent fetal bovine serum, IV and PIV are concentrations over 500-fold from river water inoculated with virus. Virus recoveries are between 80 and 100 percent. The IV and PIV fractions are assayed respectively before and after treatment with 200 ug fo chymotrypsin per millileter. When PIV is precipitated from river water, and the precipitate is dissolved and stored at 20 degrees C as a protamine-virus concentrate, only 5 percent of the viral infectivity is lost after 14 days. Therefore, reovirus can be precipitated from water at the sampling site, and only the protamine concentrate needs to be taken to the laboratory to be examined for virus content. When reoviruses are treated with chlorine, PIV is more resistant to inactivation thatn IV, and PIV appears to be at least as resistant to chlorination as poliovirus and coxsackievirus A-2. Granular media filtration systems (i.e., sand, anthracite coal and sand; anthracite coal; sand and garnet) are ineffectual in the removal of the acteriophage MS 2 from water when used as in-line direct filters. Batch assays have indicated a 93 percent reduction of MS 2 can occur when polyelectrolytes are added to the water. In addition, alum concentrations of 20, 30, 40, and 50 mg/1 remove 80 to 98 percent of the virus by precipitation. No reduction of MS 2 was observed at alum concentrations from 1 to 10 mg/1

An evolutionary driver of interspersed segmental duplications in primates

Background The complex interspersed pattern of segmental duplications in humans is responsible for rearrangements associated with neurodevelopmental disease, including the emergence of novel genes important in human brain evolution. We investigate the evolution of LCR16a, a putative driver of this phenomenon that encodes one of the most rapidly evolving human–ape gene families, nuclear pore interacting protein (NPIP). Results Comparative analysis shows that LCR16a has independently expanded in five primate lineages over the last 35 million years of primate evolution. The expansions are associated with independent lineage-specific segmental duplications flanking LCR16a leading to the emergence of large interspersed duplication blocks at non-orthologous chromosomal locations in each primate lineage. The intron-exon structure of the NPIP gene family has changed dramatically throughout primate evolution with different branches showing characteristic gene models yet maintaining an open reading frame. In the African ape lineage, we detect signatures of positive selection that occurred after a transition to more ubiquitous expression among great ape tissues when compared to Old World and New World monkeys. Mouse transgenic experiments from baboon and human genomic loci confirm these expression differences and suggest that the broader ape expression pattern arose due to mutational changes that emerged in cis. Conclusions LCR16a promotes serial interspersed duplications and creates hotspots of genomic instability that appear to be an ancient property of primate genomes. Dramatic changes to NPIP gene structure and altered tissue expression preceded major bouts of positive selection in the African ape lineage, suggestive of a gene undergoing strong adaptive evolution

Neurodevelopmental Outcome of Young Children with Biliary Atresia and Native Liver: Results from the ChiLDReN Study

OBJECTIVES: To assess neurodevelopmental outcomes among participants with biliary atresia with their native liver at ages 12 months (group 1) and 24 months (group 2), and to evaluate variables predictive of neurodevelopmental impairment. STUDY DESIGN: Participants enrolled in a prospective, longitudinal, multicenter study underwent neurodevelopmental testing with either the Bayley Scales of Infant Development, 2nd edition, or Bayley Scales of Infant and Toddler Development, 3rd edition. Scores (normative mean = 100 ± 15) were categorized as ≥100, 85-99, and <85 for χ2 analysis. Risk for neurodevelopmental impairment (defined as ≥1 score of <85 on the Bayley Scales of Infant Development, 2nd edition, or Bayley Scales of Infant and Toddler Development, 3rd edition, scales) was analyzed using logistic regression. RESULTS: There were 148 children who completed 217 Bayley Scales of Infant and Toddler Development, 3rd edition, examinations (group 1, n = 132; group 2, n = 85). Neurodevelopmental score distributions significantly shifted downward compared with test norms at 1 and 2 years of age. Multivariate analysis identified ascites (OR, 3.17; P = .01) and low length z-scores at time of testing (OR, 0.70; P < .04) as risk factors for physical/motor impairment; low weight z-score (OR, 0.57; P = .001) and ascites (OR, 2.89; P = .01) for mental/cognitive/language impairment at 1 year of age. An unsuccessful hepatoportoenterostomy was predictive of both physical/motor (OR, 4.88; P < .02) and mental/cognitive/language impairment (OR, 4.76; P = .02) at 2 years of age. CONCLUSION: Participants with biliary atresia surviving with native livers after hepatoportoenterostomy are at increased risk for neurodevelopmental delays at 12 and 24 months of age. Those with unsuccessful hepatoportoenterostomy are >4 times more likely to have neurodevelopmental impairment compared with those with successful hepatoportoenterostomy. Growth delays and/or complications indicating advanced liver disease should alert clinicians to the risk for neurodevelopmental delays, and expedite appropriate interventions