Sugarbeet Production Under Reduced Tillage Prospects And Problems

A study was initiated in the fall of 1977 to obtain base line data on the applicability of reduced tillage sugarbeet production in the Red River Valley. Three reduced tillage systems were compared to a conventional system which consisted of fall plow plus secondary tillage. Results indicated warmer early spring soil temperatures, better seedling emergence, lower ground-level wind speed and no significant yield loss under reduced tillage as compared to the conventional system

High-Resolution Transit Spectroscopy of Warm Saturns

We present high-resolution optical transmission spectroscopy of two sub-Saturn mass transiting exoplanets, HAT-P-12b and WASP-69b. With relatively low densities and high atmospheric scale heights, these planets are particularly well-suited to characterization through transit spectroscopy, and serve as ideal candidates for extending previously-tested methods to lower planetary masses. Using a single transit for each planet, we take advantage of the Doppler cross-correlation technique to search for sodium, potassium, and water absorption features. Our analysis reveals a likely ($3.2\sigma$) detection of sodium absorption features in the atmosphere of HAT-P-12b, and enables us to place constraints on the presence of alkaline and molecular species in the atmospheres of both planets. With our results, we highlight the efficacy of ground-based campaigns for characterizing exoplanetary atmospheres, and pave the way for future analyses of low-mass planets.Comment: 15 pages, 11 figure

Study of fuel cells using storable rocket propellants Final report, 18 Aug. 1965 - 23 Jun. 1969

Operating fuel cells on gaseous nitrogen tetroxide and aerozine 5

Lanthanum tungstate membranes for H-2 extraction and CO2 utilization: Fabrication strategies based on sequential tape casting and plasma-spray physical vapor deposition

[EN] In the context of energy conversion efficiency and decreasing greenhouse gas emissions from power generation and energy-intensive industries, membrane technologies for H-2 extraction and CO2 capture and utilization become pronouncedly important. Mixed protonic-electronic conducting ceramic membranes are hence attractive for the pre-combustion integrated gasification combined cycle, specifically in the water gas shift and H-2 separation process, and also for designing catalytic membrane reactors. This work presents the fabrication, microstructure and functional properties of Lanthanum tungstates (La28-xW4+xO54+delta, LaWO) asymmetric membranes supported on porous ceramic and porous metallic substrates fabricated by means of the sequential tape casting route and plasma spray-physical vapor deposition (PS-PVD). Pure LaWO and W site substituted LaWO were employed as membrane materials due to the promising combination of properties: appreciable mixed protonic-electronic conductivity at intermediate temperatures and reducing atmospheres, good sinterability and noticeable chemical stability under harsh operating conditions. As substrate materials porous LaWO (non-substituted), MgO and Crofer22APU stainless steel were used to support various LaWO membrane layers. The effect of fabrication parameters and material combinations on the assemblies' microstructure, LaWO phase formation and gas tightness of the functional layers was explored along with the related fabrication challenges for shaping LaWO layers with sufficient quality for further practical application. The two different fabrication strategies used in the present work allow for preparing all-ceramic and ceramic-metallic assemblies with LaWO membrane layers with thicknesses between 25 and 60 mu m and H-2 flux of ca. 0.4 ml/min cm(2) measured at 825 degrees C in 50 vol% H-2 in He dry feed and humid Ar sweep configuration. Such a performance is an exceptional achievement for the LaWO based H-2 separation membranes and it is well comparable with the H-2 flux reported for other newly developed dual phase cer-cer and cer-met membranes.ProtOMem Project under the BMBF grant 03SF0537 is gratefully acknowledged. Furthermore, the authors thank Ralf Laufs for his assistance in operating the PS-PVD facility. Dr. A. Schwedt from the Central Facility for Electron Microscopy (Gemeinschaftslabor fur Elektronenmikroskopie GFE), RWTH Aachen University is acknowledged for performing the EBSD analysis on the PS-PVD samples.Ivanova, ME.; Deibert, W.; Marcano, D.; Escolástico Rozalén, S.; Mauer, G.; Meulenberg, WA.; Bram, M.... (2019). Lanthanum tungstate membranes for H-2 extraction and CO2 utilization: Fabrication strategies based on sequential tape casting and plasma-spray physical vapor deposition. Separation and Purification Technology. 219:100-112. https://doi.org/10.1016/j.seppur.2019.03.015S100112219A.A. Evers, The hydrogen society, More than just a vision? ISBN 978-3-937863-31-3, Hydrogeit Verlag, 16727 Oberkraemer, Germany, 2010.Deibert, W., Ivanova, M. E., Baumann, S., Guillon, O., & Meulenberg, W. A. (2017). Ion-conducting ceramic membrane reactors for high-temperature applications. Journal of Membrane Science, 543, 79-97. doi:10.1016/j.memsci.2017.08.016Arun C. Bose, Inorganic membranes for energy and environmental applications, Edt. A. C. Bose, ISBN: 978-0-387-34524-6, Springer Science+Business Media, LLC, 2009.M. Marrony, H. Matsumoto, N. Fukatsu, M. Stoukides, Typical applications of proton ceramic cells: a way to market? in: M. Marrony (ed.), Proton-conducting ceramics. From fundamentals to applied research, by Pan Stanford Publishing Pte. Ltd., ISBN 978-981-4613-84-2, 2016.Di Giorgio, P., & Desideri, U. (2016). Potential of Reversible Solid Oxide Cells as Electricity Storage System. Energies, 9(8), 662. doi:10.3390/en9080662A.L. Dicks, D.A.J. Rand, Fuel cell systems explained, ISBN: 9781118613528, John Wiley & Sons Ltd., 2018.Zheng, Y., Wang, J., Yu, B., Zhang, W., Chen, J., Qiao, J., & Zhang, J. (2017). A review of high temperature co-electrolysis of H2O and CO2to produce sustainable fuels using solid oxide electrolysis cells (SOECs): advanced materials and technology. Chemical Society Reviews, 46(5), 1427-1463. doi:10.1039/c6cs00403bGötz, M., Lefebvre, J., Mörs, F., McDaniel Koch, A., Graf, F., Bajohr, S., … Kolb, T. (2016). Renewable Power-to-Gas: A technological and economic review. Renewable Energy, 85, 1371-1390. doi:10.1016/j.renene.2015.07.066Woodhead publishing series in energy, Nr. 76, Membrane reactors for energy applications and basic chemical production, Edt. A. Basile, L. Di Paola, F.I. Hai, V. Piemonte, by Elsevier Ltd, ISBN 978-1-78242-223-5, 2015.Morejudo, S. H., Zanón, R., Escolástico, S., Yuste-Tirados, I., Malerød-Fjeld, H., Vestre, P. K., … Kjølseth, C. (2016). Direct conversion of methane to aromatics in a catalytic co-ionic membrane reactor. Science, 353(6299), 563-566. doi:10.1126/science.aag0274Malerød-Fjeld, H., Clark, D., Yuste-Tirados, I., Zanón, R., Catalán-Martinez, D., Beeaff, D., … Kjølseth, C. (2017). Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss. 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Serra, Hydrogen separation through tailored dual phase membranes with nominal composition BaCe0.8Eu0.2O3−δ:Ce0.8Y0.2O2−δ at intermediate temperatures, Sci. Rep. 6 (2016) 34773–34787.S. Elangovan, B.G. Nair, T.A. Small, Ceramic mixed protonic-electronic conducting membranes for hydrogen separation (2007), US 7,258,820 B2, 1997.Rosensteel, W. A., Ricote, S., & Sullivan, N. P. (2016). Hydrogen permeation through dense BaCe 0.8 Y 0.2 O 3−δ – Ce 0.8 Y 0.2 O 2−δ composite-ceramic hydrogen separation membranes. International Journal of Hydrogen Energy, 41(4), 2598-2606. doi:10.1016/j.ijhydene.2015.11.053Rebollo, E., Mortalò, C., Escolástico, S., Boldrini, S., Barison, S., Serra, J. M., & Fabrizio, M. (2015). Exceptional hydrogen permeation of all-ceramic composite robust membranes based on BaCe0.65Zr0.20Y0.15O3−δ and Y- or Gd-doped ceria. Energy & Environmental Science, 8(12), 3675-3686. doi:10.1039/c5ee01793aMontaleone, D., Mercadelli, E., Escolástico, S., Gondolini, A., Serra, J. M., & Sanson, A. (2018). All-ceramic asymmetric membranes with superior hydrogen permeation. Journal of Materials Chemistry A, 6(32), 15718-15727. doi:10.1039/c8ta04764bKim, H., Kim, B., Lee, J., Ahn, K., Kim, H.-R., Yoon, K. J., … Lee, J.-H. (2014). Microstructural adjustment of Ni–BaCe0.9Y0.1O3−δ cermet membrane for improved hydrogen permeation. Ceramics International, 40(3), 4117-4126. doi:10.1016/j.ceramint.2013.08.066(Balu) Balachandran, U., Lee, T. H., Park, C. Y., Emerson, J. E., Picciolo, J. J., & Dorris, S. E. (2014). Dense cermet membranes for hydrogen separation. Separation and Purification Technology, 121, 54-59. doi:10.1016/j.seppur.2013.10.001Shimura, T. (2001). Proton conduction in non-perovskite-type oxides at elevated temperatures. Solid State Ionics, 143(1), 117-123. doi:10.1016/s0167-2738(01)00839-6HAUGSRUD, R. (2007). Defects and transport properties in Ln6WO12 (Ln=La, Nd, Gd, Er). Solid State Ionics, 178(7-10), 555-560. doi:10.1016/j.ssi.2007.01.004Haugsrud, R., & Kjølseth, C. (2008). Effects of protons and acceptor substitution on the electrical conductivity of La6WO12. Journal of Physics and Chemistry of Solids, 69(7), 1758-1765. doi:10.1016/j.jpcs.2008.01.002Magrasó, A., Polfus, J. M., Frontera, C., Canales-Vázquez, J., Kalland, L.-E., Hervoches, C. H., … Haugsrud, R. (2012). Complete structural model for lanthanum tungstate: a chemically stable high temperature proton conductor by means of intrinsic defects. J. Mater. Chem., 22(5), 1762-1764. doi:10.1039/c2jm14981hSeeger, J., Ivanova, M. E., Meulenberg, W. A., Sebold, D., Stöver, D., Scherb, T., … Serra, J. M. (2013). Synthesis and Characterization of Nonsubstituted and Substituted Proton-Conducting La6–xWO12–y. Inorganic Chemistry, 52(18), 10375-10386. doi:10.1021/ic401104mScherb, T., Kimber, S. A. J., Stephan, C., Henry, P. F., Schumacher, G., Escolástico, S., … Banhart, J. (2016). Nanoscale order in the frustrated mixed conductor La5.6WO12−δ. Journal of Applied Crystallography, 49(3), 997-1008. doi:10.1107/s1600576716006415Van Holt, D., Forster, E., Ivanova, M. E., Meulenberg, W. A., Müller, M., Baumann, S., & Vaßen, R. (2014). Ceramic materials for H2 transport membranes applicable for gas separation under coal-gasification-related conditions. Journal of the European Ceramic Society, 34(10), 2381-2389. doi:10.1016/j.jeurceramsoc.2014.03.001Forster, E., van Holt, D., Ivanova, M. E., Baumann, S., Meulenberg, W. A., & Müller, M. (2016). Stability of ceramic materials for H2 transport membranes in gasification environment under the influence of gas contaminants. Journal of the European Ceramic Society, 36(14), 3457-3464. doi:10.1016/j.jeurceramsoc.2016.05.021Medvedev, D., Lyagaeva, J., Plaksin, S., Demin, A., & Tsiakaras, P. (2015). Sulfur and carbon tolerance of BaCeO3–BaZrO3 proton-conducting materials. Journal of Power Sources, 273, 716-723. doi:10.1016/j.jpowsour.2014.09.116Yang, L., Wang, S., Blinn, K., Liu, M., Liu, Z., Cheng, Z., & Liu, M. (2009). Enhanced Sulfur and Coking Tolerance of a Mixed Ion Conductor for SOFCs: BaZr 0.1 Ce 0.7 Y 0.2– x Yb x O 3–δ. Science, 326(5949), 126-129. doi:10.1126/science.1174811Duan, C., Kee, R. J., Zhu, H., Karakaya, C., Chen, Y., Ricote, S., … O’Hayre, R. (2018). Highly durable, coking and sulfur tolerant, fuel-flexible protonic ceramic fuel cells. Nature, 557(7704), 217-222. doi:10.1038/s41586-018-0082-6Kreuer, K. D. (2003). Proton-Conducting Oxides. Annual Review of Materials Research, 33(1), 333-359. doi:10.1146/annurev.matsci.33.022802.091825Fantin, A., Scherb, T., Seeger, J., Schumacher, G., Gerhards, U., Ivanova, M. E., … Banhart, J. (2016). Crystal structure of Re-substituted lanthanum tungstate La5.4W1−y Re y O12–δ (0 ≤ y ≤ 0.2) studied by neutron diffraction. Journal of Applied Crystallography, 49(5), 1544-1560. doi:10.1107/s1600576716011523Fantin, A., Scherb, T., Seeger, J., Schumacher, G., Gerhards, U., Ivanova, M. E., … Banhart, J. (2017). Relation between composition and vacant oxygen sites in the mixed ionic-electronic conductors La5.4W1−MO12− (M= Mo, Re; 0 ≤y≤ 0.2) and their mother compound La6−WO12− (0.4 ≤x≤ 0.8). Solid State Ionics, 306, 104-111. doi:10.1016/j.ssi.2017.04.005J.M. Serra, S. Escolástico, M.E. Ivanova, W.A. Meulenberg, H.-P. Buchkremer, D. Stöver, US2013-0216938-A1, 2013.Escolastico, S., Seeger, J., Roitsch, S., Ivanova, M., Meulenberg, W. A., & Serra, J. M. (2013). Enhanced H2Separation through Mixed Proton-Electron Conducting Membranes Based on La5.5W0.8M0.2O11.25−δ. ChemSusChem, 6(8), 1523-1532. doi:10.1002/cssc.201300091Gil, V., Gurauskis, J., Kjølseth, C., Wiik, K., & Einarsrud, M.-A. (2013). Hydrogen permeation in asymmetric La28 − xW4 + xO54 + 3x/2 membranes. 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(2013). Plasma Spray Physical Vapor Deposition of La1−x Sr x Co y Fe1−y O3−δ Thin-Film Oxygen Transport Membrane on Porous Metallic Supports. Journal of Thermal Spray Technology, 23(1-2), 213-219. doi:10.1007/s11666-013-0004-yMarcano, D., Mauer, G., Sohn, Y. J., Vaßen, R., Garcia-Fayos, J., & Serra, J. M. (2016). Controlling the stress state of La1−Sr Co Fe1−O3− oxygen transport membranes on porous metallic supports deposited by plasma spray–physical vapor process. Journal of Membrane Science, 503, 1-7. doi:10.1016/j.memsci.2015.12.029Marcano, D., Mauer, G., Vaßen, R., & Weber, A. (2017). Manufacturing of high performance solid oxide fuel cells (SOFCs) with atmospheric plasma spraying (APS) and plasma spray-physical vapor deposition (PS-PVD). Surface and Coatings Technology, 318, 170-177. doi:10.1016/j.surfcoat.2016.10.088D. Marcano, G. Mauer, Y.J. Sohn, A. Schwedt, M. Bram, M.E. Ivanova, R. 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Highly conductive grain boundaries in cold-sintered barium zirconate-based proton conductors

Proton-conducting barium zirconate ceramics have shown large potential for efficient electrochemical conversion and separation processes at intermediate operation temperatures. The high energy efficiency, robustness, and intermediate-temperature operation (500-650 °C) make proton-conducting cells promising candidates for future energy conversion systems. However, the major disadvantages of these materials are the inevitable high-sintering temperatures (>1500 °C), leading to Ba-evaporation and formation of high-resistance grain boundaries, which dominate the electrochemical performance. Here, we introduce a novel processing route for proton-conducting barium zirconates, which, on the one hand, significantly lowers the maximum processing temperature and, on the other hand, overcomes the dominating influence of grain boundaries on total conductivity. The key step of this novel processing route is the cold sintering of the powder using pure water as a sintering aid to consolidate BaZrCeYO (BZCY) at 350 °C. We show that clean grain boundaries with a high acceptor-dopant concentration are preserved thanks to the recovery of the perovskite phase during thermal treatment at 1300 °C. This compensates the interfacial core charge, resulting in highly conductive grain boundaries, which do not limit the total conductivity. Consequently, dense BZCY electrolytes produced by our novel approach outperform the conductivity of conventionally sintered BZCY irrespective of the significantly lower maximum processing temperature and its nanocrystalline microstructure. Our presented approach opens up new possibilities for grain boundary engineering and might facilitate novel co-sintering pathways for barium zirconate-based components.The authors acknowledge Dr Doris Sebold for help with SEM investigations and Dr Yoo Jung Sohn for assistance with HT-XRD measurements. M. K. acknowledges financial support from the DFG under project number MA 1280/69-1. Additionally, D. J. and W. R. thank the DFG for funding within the Emmy Noether program (RH 146/1-1). A. V. expresses gratitude to Dr Ivan Povstugar for his insightful discussions on the quality of APT data and its reconstruction. The authors thank Hitachi High-Technologies for providing access to the HF5000 STEM located at ER-C

Phosphodiesterase-5 inhibitors have distinct effects on the hemodynamics of the liver

<p>Abstract</p> <p>Background</p> <p>The NO - cGMP system plays a key role in the regulation of sinusoidal tonus and liver blood flow with phosphodiesterase-5 (PDE-5) terminating the dilatory action of cGMP. We, therefore, investigated the effects of PDE-5 inhibitors on hepatic and systemic hemodynamics in rats.</p> <p>Methods</p> <p>Hemodynamic parameters were monitored for 60 min. after intravenous injection of sildenafil and vardenafil [1, 10 and 100 μg/kg (sil1, sil10, sil100, var1, var10, var100)] in anesthetized rats.</p> <p>Results</p> <p>Cardiac output and heart rate remained constant. After a short dip, mean arterial blood pressure again increased. Systemic vascular resistance transiently decreased slightly. Changes in hepatic hemodynamic parameters started after few minutes and continued for at least 60 min. Portal (var10 -31%, sil10 -34%) and hepatic arterial resistance (var10 -30%, sil10 -32%) decreased significantly (p < 0.05). At the same time portal venous (var10 +29%, sil10 +24%), hepatic arterial (var10 +34%, sil10 +48%), and hepatic parenchymal blood flow (var10 +15%, sil10 +15%) increased significantly (p < 0.05). The fractional liver blood flow (total liver flow/cardiac output) increased significantly (var10 26%, sil10 23%). Portal pressure remained constant or tended to decrease. 10 μg/kg was the most effective dose for both PDE-5 inhibitors.</p> <p>Conclusion</p> <p>Low doses of phosphodiesterase-5 inhibitors have distinct effects on hepatic hemodynamic parameters. Their therapeutic use in portal hypertension should therefore be evaluated.</p

Direct tactile stimulation of dorsal occipito-temporal cortex in a visual agnosic

The human occipito-temporal cortex is preferentially activated by images of objects as opposed to scrambled images [1]. Touching objects (versus textures) also activates this region [2–10]. We used neuropsychological fMRI to probe whether dorsal regions of the lateral occipital cortex (LO) are activated in tactile recognition without mediation through visual recognition. We tested a patient (HJA) with visual agnosia due to bilateral lesions of the ventral occipito-temporal cortex but spared dorsal LO. HJA's recognition of visual objects was impaired [11, 12]. Nevertheless, his tactile recognition was preserved. We measured brain activity while participants viewed and touched objects and textures. There was overlapping activity in regions including LO and cerebellum for both stimuli for control participants, including new regions not before considered bimodal. For HJA, there were overlapping regions in the intact dorsal LO. Within a subset of the regions found in control participants, HJA showed activity only for tactile objects, suggesting that these regions are specifically involved in successful multimodal recognition. Activation of dorsal LO by tactile input is not secondary to visual recognition but can operate directly through tactile input

The structure of SgrAI bound to DNA; recognition of an 8 base pair target

The three-dimensional X-ray crystal structure of the ‘rare cutting’ type II restriction endonuclease SgrAI bound to cognate DNA is presented. SgrAI forms a dimer bound to one duplex of DNA. Two Ca2+ bind in the enzyme active site, with one ion at the interface between the protein and DNA, and the second bound distal from the DNA. These sites are differentially occupied by Mn2+, with strong binding at the protein–DNA interface, but only partial occupancy of the distal site. The DNA remains uncleaved in the structures from crystals grown in the presence of either divalent cation. The structure of the dimer of SgrAI is similar to those of Cfr10I, Bse634I and NgoMIV, however no tetrameric structure of SgrAI is observed. DNA contacts to the central CCGG base pairs of the SgrAI canonical target sequence (CR|CCGGYG, | marks the site of cleavage) are found to be very similar to those in the NgoMIV/DNA structure (target sequence G|CCGGC). Specificity at the degenerate YR base pairs of the SgrAI sequence may occur via indirect readout using DNA distortion. Recognition of the outer GC base pairs occurs through a single contact to the G from an arginine side chain located in a region unique to SgrAI