Using an inverse modelling approach to evaluate the water retention in a simple water harvesting technique

In arid and semi-arid zones, runoff harvesting techniques are often applied to increase the water retention and infiltration on steep slopes. Additionally, they act as an erosion control measure to reduce land degradation hazards. Nevertheless, few efforts were observed to quantify the water harvesting processes of these techniques and to evaluate their efficiency. In this study, a combination of detailed field measurements and modelling with the HYDRUS-2D software package was used to visualize the effect of an infiltration trench on the soil water content of a bare slope in northern Chile. Rainfall simulations were combined with high spatial and temporal resolution water content monitoring in order to construct a useful dataset for inverse modelling purposes. Initial estimates of model parameters were provided by detailed infiltration and soil water retention measurements. Four different measurement techniques were used to determine the saturated hydraulic conductivity (<I>K</I><sub>sat</sub>) independently. The tension infiltrometer measurements proved a good estimator of the <I>K</I><sub>sat</sub> value and a proxy for those measured under simulated rainfall, whereas the pressure and constant head well infiltrometer measurements showed larger variability. Six different parameter optimization functions were tested as a combination of soil-water content, water retention and cumulative infiltration data. Infiltration data alone proved insufficient to obtain high model accuracy, due to large scatter on the data set, and water content data were needed to obtain optimized effective parameter sets with small confidence intervals. Correlation between the observed soil water content and the simulated values was as high as <I>R</I><sup>2</sup>=0.93 for ten selected observation points used in the model calibration phase, with overall correlation for the 22 observation points equal to 0.85. The model results indicate that the infiltration trench has a significant effect on soil-water storage, especially at the base of the trench

Closing the knowing-applying gap in water utilities: experience from Uganda's NWSC

In recent decades, there has been a steady rise of knowledge and capacity development (KCD) interventions targeting water utilities in developing countries. However, field experiences show that very often little change occurs in what water utilities' professionals and managers do as a result of capacity development efforts. Notwithstanding that, there are also some cases of success. In this paper, the authors argue that very often the main challenge facing utilities is not the development of utility competences per se, but their actual use. Drawing on the case of Uganda's National Water and Sewerage Corporation, we identify and discuss five interrelated factors that have allowed the corporation to progressively turn its knowledge base into improved performance, by means of its change management programmes. The paper concludes that water utilities can bridge the knowing-applying gap by carefully introducing a corporate culture, and management systems and structures that motivate staff to apply their knowledge

Characterization of nuclear material by Neutron Resonance Transmission Analysis

The use of Neutron Resonance Transmission Analysis for the characterization of nuclear materials is discussed. The method, which relies on resonance structures in neutron-induced reaction cross sections, can be applied as a non-destructive method to characterise complex nuclear materials such as melted fuel resulting from a severe nuclear accident. Results of a demonstration experiment at the GELINA facility reveal that accurate data can be obtained at a compact facility even in the case of strong overlapping resonances

Combining oxytocin and cognitive bias modification training in a randomized controlled trial:Effects on trust in maternal support

Background and objectives: Research on the social effects of intranasal oxytocin in children is scarce. Oxytocin has been proposed to have clearer beneficial effects when added to social learning paradigms. The current study tested this proposition in middle childhood by assessing effects of cognitive bias modification (CBM) training and oxytocin on trust in maternal support. Methods: Children (N = 100, 8–12 years) were randomly assigned to one of two training conditions: CBM training aimed at increasing trust or neutral placebo training. Within each training condition, half the participants received oxytocin and half a placebo. Main and interaction effects were assessed on measures of trust-related interpretation bias and trust. We explored whether child characteristics moderated intervention effects. Results: Children in the CBM training were faster to interpret maternal behaviour securely versus insecurely. Effects did not generalize to interpretation bias measures or trust. There were no main or interaction effects of oxytocin. Exploratory moderation analyses indicated that combining CBM training with oxytocin had less positive effects on trust for children with more internalizing problems. Limitations: As this was the first study combining CBM and oxytocin, replication of the results is needed. Conclusions: This study combined a social learning paradigm with oxytocin in children. CBM training was effective at an automatic level of processing. Oxytocin did not enhance CBM effects or independently exert effects. Research in larger samples specifying when oxytocin might have beneficial effects is necessary before oxytocin can be used as intervention option in children

Reflecting on mirror mechanisms:motor resonance effects during action observation only present with low-intensity transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) studies indicate that the observation of other people's actions influences the excitability of the observer's motor system. Motor evoked potential (MEP) amplitudes typically increase in muscles which would be active during the execution of the observed action. This 'motor resonance' effect is thought to result from activity in mirror neuron regions, which enhance the excitability of the primary motor cortex (M1) via cortico-cortical pathways. The importance of TMS intensity has not yet been recognised in this area of research. Low-intensity TMS predominately activates corticospinal neurons indirectly, whereas high-intensity TMS can directly activate corticospinal axons. This indicates that motor resonance effects should be more prominent when using low-intensity TMS. A related issue is that TMS is typically applied over a single optimal scalp position (OSP) to simultaneously elicit MEPs from several muscles. Whether this confounds results, due to differences in the manner that TMS activates spatially separate cortical representations, has not yet been explored. In the current study, MEP amplitudes, resulting from single-pulse TMS applied over M1, were recorded from the first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles during the observation of simple finger abductions. We tested if the TMS intensity (110% vs. 130% resting motor threshold) or stimulating position (FDI-OSP vs. ADM-OSP) influenced the magnitude of the motor resonance effects. Results showed that the MEP facilitation recorded in the FDI muscle during the observation of index-finger abductions was only detected using low-intensity TMS. In contrast, changes in the OSP had a negligible effect on the presence of motor resonance effects in either the FDI or ADM muscles. These findings support the hypothesis that MN activity enhances M1 excitability via cortico-cortical pathways and highlight a methodological framework by which the neural underpinnings of action observation can be further explored. © 2013 Loporto et al

Host-guest and guest-guest interactions between xylene isomers confined in the MIL-47(V) pore system

The porous MIL-47 material shows a selective adsorption behavior for para-, ortho-, and meta-isomers of xylenes, making the material a serious candidate for separation applications. The origin of the selectivity lies in the differences in interactions (energetic) and confining (entropic). This paper investigates the xylene-framework interactions and the xylene-xylene interactions with quantum mechanical calculations, using a dispersion-corrected density functional and periodic boundary conditions to describe the crystal. First, the strength and geometrical characteristics of the optimal xylene-xylene interactions are quantified by studying the pure and mixed pairs in gas phase. An extended set of initial structures is created and optimized to sample as many relative orientations and distances as possible. Next, the pairs are brought in the pores of MIL-47. The interaction with the terephthalic linkers and other xylenes increases the stacking energy in gas phase (-31.7 kJ/mol per pair) by roughly a factor four in the fully loaded state (-58.3 kJ/mol per xylene). Our decomposition of the adsorption energy shows various trends in the contributing xylene-xylene interactions. The absence of a significant difference in energetics between the isomers indicates that entropic effects must be mainly responsible for the separation behavior

MOFs as multifunctional catalysts: One-pot synthesis of menthol from citronellal over a bifunctional MIL-101 catalyst

A bifunctional MOF catalyst containing coordinatively unsaturated Cr3+ sites and palladium nanoparticles (Pd@MIL-101) has been used for the cyclization of citronellal to isopulegol and for the one-pot tandem isomerization/hydrogenation of citronellal to menthol. The MOF was found to be stable under the reaction conditions used, and the results obtained indicate that the performance of this bifunctional solid catalyst is comparable with other state-of-the-art materials for the tandem reaction: Full citronellal conversion was attained over Pd@MIL-101 in 18 h, with 86% selectivity to menthols and a diastereoselectivity of 81% to the desired (-)-menthol, while up to 30 h were necessary for attaining similar values over Ir/H-beta under analogous reaction conditions.Financial support by Ministerio de Educacion y Ciencia e Innovacion (Project MIYCIN, CSD2009-00050; PROGRAMA CONSOLIDER. INGENIO 2009), Generalidad Valenciana (GV PROMETEO/2008/130) and the CSIC (Proyectos Intramurales Especiales 201080I020) is gratefully acknowledged.García Cirujano, F.; Llabrés I Xamena, FX.; Corma Canós, A. (2012). MOFs as multifunctional catalysts: One-pot synthesis of menthol from citronellal over a bifunctional MIL-101 catalyst. Dalton Transactions. 41:4249-4254. https://doi.org/10.1039/c2dt12480gS4249425441Corma, A., García, H., & Llabrés i Xamena, F. X. (2010). Engineering Metal Organic Frameworks for Heterogeneous Catalysis. Chemical Reviews, 110(8), 4606-4655. doi:10.1021/cr9003924Farrusseng, D., Aguado, S., & Pinel, C. (2009). Metal-Organic Frameworks: Opportunities for Catalysis. Angewandte Chemie International Edition, 48(41), 7502-7513. doi:10.1002/anie.200806063Lee, J., Farha, O. K., Roberts, J., Scheidt, K. A., Nguyen, S. T., & Hupp, J. T. (2009). Metal–organic framework materials as catalysts. Chemical Society Reviews, 38(5), 1450. doi:10.1039/b807080fWang, Z., & Cohen, S. M. (2009). Postsynthetic modification of metal–organic frameworks. Chemical Society Reviews, 38(5), 1315. doi:10.1039/b802258pBanerjee, M., Das, S., Yoon, M., Choi, H. J., Hyun, M. H., Park, S. M., … Kim, K. (2009). Postsynthetic Modification Switches an Achiral Framework to Catalytically Active Homochiral Metal−Organic Porous Materials. Journal of the American Chemical Society, 131(22), 7524-7525. doi:10.1021/ja901440gGASCON, J., AKTAY, U., HERNANDEZALONSO, M., VANKLINK, G., & KAPTEIJN, F. (2009). Amino-based metal-organic frameworks as stable, highly active basic catalysts. Journal of Catalysis, 261(1), 75-87. doi:10.1016/j.jcat.2008.11.010Hasegawa, S., Horike, S., Matsuda, R., Furukawa, S., Mochizuki, K., Kinoshita, Y., & Kitagawa, S. (2007). Three-Dimensional Porous Coordination Polymer Functionalized with Amide Groups Based on Tridentate Ligand:  Selective Sorption and Catalysis. Journal of the American Chemical Society, 129(9), 2607-2614. doi:10.1021/ja067374yCho, S.-H., Ma, B., Nguyen, S. T., Hupp, J. T., & Albrecht-Schmitt, T. E. (2006). A metal–organic framework material that functions as an enantioselective catalyst for olefin epoxidation. Chem. Commun., (24), 2563-2565. doi:10.1039/b600408cZhang, X., Llabrés i Xamena, F. X., & Corma, A. (2009). Gold(III) – metal organic framework bridges the gap between homogeneous and heterogeneous gold catalysts. Journal of Catalysis, 265(2), 155-160. doi:10.1016/j.jcat.2009.04.021Meilikhov, M., Yusenko, K., Esken, D., Turner, S., Van Tendeloo, G., & Fischer, R. A. (2010). Metals@MOFs - Loading MOFs with Metal Nanoparticles for Hybrid Functions. European Journal of Inorganic Chemistry, 2010(24), 3701-3714. doi:10.1002/ejic.201000473Henschel, A., Gedrich, K., Kraehnert, R., & Kaskel, S. (2008). Catalytic properties of MIL-101. Chemical Communications, (35), 4192. doi:10.1039/b718371bVermoortele, F., Ameloot, R., Vimont, A., Serre, C., & De Vos, D. (2011). An amino-modified Zr-terephthalate metal–organic framework as an acid–base catalyst for cross-aldol condensation. Chem. Commun., 47(5), 1521-1523. doi:10.1039/c0cc03038dWu, P., Wang, J., Li, Y., He, C., Xie, Z., & Duan, C. (2011). Luminescent Sensing and Catalytic Performances of a Multifunctional Lanthanide-Organic Framework Comprising a Triphenylamine Moiety. Advanced Functional Materials, 21(14), 2788-2794. doi:10.1002/adfm.201100115Pan, Y., Yuan, B., Li, Y., & He, D. (2010). Multifunctional catalysis by Pd@MIL-101: one-step synthesis of methyl isobutyl ketone over palladium nanoparticles deposited on a metal–organic framework. Chemical Communications, 46(13), 2280. doi:10.1039/b922061eCliment, M. J., Corma, A., Guil-López, R., Iborra, S., & Primo, J. (1998). Use of Mesoporous MCM-41 Aluminosilicates as Catalysts in the Preparation of Fine Chemicals. Journal of Catalysis, 175(1), 70-79. doi:10.1006/jcat.1998.1970Climent, M. J., Corma, A., Iborra, S., & Velty, A. (2002). Designing the adequate base solid catalyst with Lewis or Bronsted basic sites or with acid–base pairs. Journal of Molecular Catalysis A: Chemical, 182-183, 327-342. doi:10.1016/s1381-1169(01)00501-5Boronat, M., Climent, M. J., Corma, A., Iborra, S., Montón, R., & Sabater, M. J. (2010). Bifunctional Acid-Base Ionic Liquid Organocatalysts with a Controlled Distance Between Acid and Base Sites. Chemistry - A European Journal, 16(4), 1221-1231. doi:10.1002/chem.200901519Corma, A., Díaz, U., García, T., Sastre, G., & Velty, A. (2010). Multifunctional Hybrid Organic−Inorganic Catalytic Materials with a Hierarchical System of Well-Defined Micro- and Mesopores. Journal of the American Chemical Society, 132(42), 15011-15021. doi:10.1021/ja106272zFerey, G. (2005). A Chromium Terephthalate-Based Solid with Unusually Large Pore Volumes and Surface Area. Science, 309(5743), 2040-2042. doi:10.1126/science.1116275Corma, A., & Renz, M. (2004). Sn-Beta zeolite as diastereoselective water-resistant heterogeneous Lewis-acid catalyst for carbon–carbon bond formation in the intramolecular carbonyl–ene reaction. Chem. Commun., (5), 550-551. doi:10.1039/b313738dIosif, F., Coman, S., Pârvulescu, V., Grange, P., Delsarte, S., Vos, D. D., & Jacobs, P. (2004). Ir-Beta zeolite as a heterogeneous catalyst for the one-pot transformation of citronellal to menthol. Chem. Commun., (11), 1292-1293. doi:10.1039/b403692aNeaţu, F., Coman, S., Pârvulescu, V. I., Poncelet, G., De Vos, D., & Jacobs, P. (2009). Heterogeneous Catalytic Transformation of Citronellal to Menthol in a Single Step on Ir-Beta Zeolite Catalysts. Topics in Catalysis, 52(9), 1292-1300. doi:10.1007/s11244-009-9270-9MERTENS, P., VERPOORT, F., PARVULESCU, A., & DEVOS, D. (2006). Pt/H-beta zeolites as productive bifunctional catalysts for the one-step citronellal-to-menthol conversion. Journal of Catalysis, 243(1), 7-13. doi:10.1016/j.jcat.2006.06.017Da Silva Rocha, K. A., Robles-Dutenhefner, P. A., Sousa, E. M. B., Kozhevnikova, E. F., Kozhevnikov, I. V., & Gusevskaya, E. V. (2007). Pd–heteropoly acid as a bifunctional heterogeneous catalyst for one-pot conversion of citronellal to menthol. Applied Catalysis A: General, 317(2), 171-174. doi:10.1016/j.apcata.2006.10.019Trasarti, A. F., Marchi, A. J., & Apesteguı́a, C. R. (2004). Highly selective synthesis of menthols from citral in a one-step process. Journal of Catalysis, 224(2), 484-488. doi:10.1016/j.jcat.2004.03.016TRASARTI, A., MARCHI, A., & APESTEGUIA, C. (2007). Design of catalyst systems for the one-pot synthesis of menthols from citral. Journal of Catalysis, 247(2), 155-165. doi:10.1016/j.jcat.2007.01.016Alaerts, L., Séguin, E., Poelman, H., Thibault-Starzyk, F., Jacobs, P. A., & De Vos, D. E. (2006). Probing the Lewis Acidity and Catalytic Activity of the Metal–Organic Framework [Cu3(btc)2] (BTC=Benzene-1,3,5-tricarboxylate). Chemistry - A European Journal, 12(28), 7353-7363. doi:10.1002/chem.200600220Horcajada, P., Surblé, S., Serre, C., Hong, D.-Y., Seo, Y.-K., Chang, J.-S., … Férey, G. (2007). Synthesis and catalytic properties of MIL-100(Fe), an iron(iii) carboxylate with large pores. Chem. Commun., (27), 2820-2822. doi:10.1039/b704325bRavon, U., Chaplais, G., Chizallet, C., Seyyedi, B., Bonino, F., Bordiga, S., … Farrusseng, D. (2010). Investigation of Acid Centers in MIL-53(Al, Ga) for Brønsted-Type Catalysis: In Situ FTIR and Ab Initio Molecular Modeling. ChemCatChem, 2(10), 1235-1238. doi:10.1002/cctc.201000055Vimont, A., Leclerc, H., Maugé, F., Daturi, M., Lavalley, J.-C., Surblé, S., … Férey, G. (2007). Creation of Controlled Brønsted Acidity on a Zeotypic Mesoporous Chromium(III) Carboxylate by Grafting Water and Alcohol Molecules. The Journal of Physical Chemistry C, 111(1), 383-388. doi:10.1021/jp064686

An absolute measurement of the neutron production rate of a spent nuclear fuel sample used for depletion code validation

A method to determine the neutron production rate of a spent nuclear fuel segment sample by means of non-destructive assay conducted under standard controlled-area conditions is described and demonstrated. A neutron well counter designed for routine nuclear safeguards applications is applied. The method relies on a transfer procedure that is adapted to the hot cell facilities at the Laboratory for High and Medium level Activity of SCK CEN in Belgium. Experiments with 252Cf(sf) sources, certified for their neutron emission rate, were carried out at the Joint Research Centre to determine the characteristics of the detection device. Measurements of a segment of a spent nuclear fuel rod were carried out at SCK CEN resulting in an absolute and non-destructive measurement of the neutron production rate avoiding any reference to a representative spent nuclear fuel sample to calibrate the device. Results of these measurements were used to study the performance of depletion codes, i.e., ALEPH2, SCALE, and Serpent2. The study includes a code-to-code and code-to-experiment comparison using different nuclear data libraries

Measurement of the 154Gd(n,?) cross section and its astrophysical implications

The neutron capture cross section of 154Gd was measured from 1 eV to 300 keV in the experimental area located 185 m from the CERN n_TOF neutron spallation source, using a metallic sample of gadolinium, enriched to 67% in 154Gd. The capture measurement, performed with four C6D6 scintillation detectors, has been complemented by a transmission measurement performed at the GELINA time-of-flight facility (JRC-Geel), thus minimising the uncertainty related to sample composition. An accurate Maxwellian averaged capture cross section (MACS) was deduced over the temperature range of interest for s process nucleosynthesis modelling. We report a value of 880(50) mb for the MACS at keV, significantly lower compared to values available in literature. The new adopted 154Gd(n,γ) cross section reduces the discrepancy between observed and calculated solar s-only isotopic abundances predicted by s-process nucleosynthesis models.Funded by SCOAP

Modulation of Brain Activity during Action Observation: Influence of Perspective, Transitivity and Meaningfulness

The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process