1,005 research outputs found

    Development of Simplified Models of Regional Groundwater and Surface Water Flow Processes based on Computational Experiments with Comprehensive Models

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    The development of complex decision support model systems for the analysis of regional water policies for regions with intense socio-economic development affecting and being affected by the water resources system is of increasing importance. One of the most illustrative examples are regions with open-pit lignite mining. Such model systems have to be based on appropriate submodels, e.g. for water quantity processes. The paper describes submodels for groundwater and surface water flow with special regard to open-pit lignite mining regions. Starting with a problem definition in Section 2 the methodological background is given. The state-of-the-art of comprehensive models of regional water flow processes based on groundwater flow models and of stochastic long-term management modeling are described in details. Section 3 gives the methodological approach for model reduction. The application of this approach is illustrated in Section 4 for the modeling of mine drainage and groundwater tables, for the modeling of remaining pit management and of groundwater-surface water interactions. In the appendix computer programs of some submodels are given being suitable for a more general application

    CO adsorption on neutral iridium clusters

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    The adsorption of carbon monoxide on neutral iridium clusters in the size range of n = 3 to 21 atoms is investigated with infrared multiple photon dissociation spectroscopy. For each cluster size only a single v(CO) band is present with frequencies in the range between 1962 cm-1 (n = 8) and 1985 cm-1 (n = 18) which can be attributed to an atop binding geometry. This behaviour is compared to the CO binding geometries on clusters of other group 9 and 10 transition metals as well as to that on extended surfaces. The preference of Ir for atop binding is rationalized by relativistic effects on the electronic structure of the later 5d metals

    Fingering Instabilities on Reaction Fronts in the CO Oxidation Reaction on Pt(100)

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    Fingering instabilities arising from local perturbations to planar reaction fronts in the CO oxidation reaction on Pt(100) are presented. CO oxidation represents a heterogeneous nonlinear system with the necessary kinetic and diffusive transport properties to support the development of fingered wave fronts. External forcing was utilized to create CO wave fronts on an otherwise monostable, O-covered surface, which, upon destabilization, gave rise to fingers of adsorbed CO extending into the O adlayer ahead of the reaction front. Finger spreading and tip-splitting were observed as the finger pattern evolved towards an intrinsic wavelength, independent of the length of the reaction front, calculated to be approximately 40 μm. Our data also show the presence of a shielding process, where at wavelengths less than twice the observed intrinsic value, additional fingers were created on the reaction front through a tip-splitting bifurcation of an existing finger. At wavelengths greater than twice the intrinsic value, additional fingers formed in the troughs between adjacent fingers, apparently unaffected by the presence of the larger surrounding fingers

    The DSM-5 dissociative-PTSD subtype: Can levels of depression, anxiety, hostility, and sleeping difficulties differentiate between dissociative-PTSD and PTSD in rape and sexual assault victims?

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    The DSM-5 currently includes a dissociative-PTSD subtype within its nomenclature. Several studies have confirmed the dissociative-PTSD subtype in both American Veteran and American civilian samples. Studies have begun to assess specific factors which differentiate between dissociative vs. non-dissociative PTSD. The current study takes a novel approach to investigating the presence of a dissociative-PTSD subtype in its use of European victims of sexual assault and rape (N= 351). Utilizing Latent Profile Analyses, we hypothesized that a discrete group of individuals would represent a dissociative-PTSD subtype. We additionally hypothesized that levels of depression, anger, hostility, and sleeping difficulties would differentiate dissociative-PTSD from a similarly severe form of PTSD in the absence of dissociation. Results concluded that there were four discrete groups termed baseline, moderate PTSD, high PTSD, and dissociative-PTSD. The dissociative-PTSD group encompassed 13.1% of the sample and evidenced significantly higher mean scores on measures of depression, anxiety, hostility, and sleeping difficulties. Implications are discussed in relation to both treatment planning and the newly published DSM-5.</p

    Cerebellar Integrity in the Amyotrophic Lateral Sclerosis - Frontotemporal Dementia Continuum

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    Amyotrophic lateral sclerosis (ALS) and behavioural variant frontotemporal dementia (bvFTD) are multisystem neurodegenerative disorders that manifest overlapping cognitive, neuropsychiatric and motor features. The cerebellum has long been known to be crucial for intact motor function although emerging evidence over the past decade has attributed cognitive and neuropsychiatric processes to this structure. The current study set out i) to establish the integrity of cerebellar subregions in the amyotrophic lateral sclerosis-behavioural variant frontotemporal dementia spectrum (ALS-bvFTD) and ii) determine whether specific cerebellar atrophy regions are associated with cognitive, neuropsychiatric and motor symptoms in the patients. Seventy-eight patients diagnosed with ALS, ALS-bvFTD, behavioural variant frontotemporal dementia (bvFTD), most without C9ORF72 gene abnormalities, and healthy controls were investigated. Participants underwent cognitive, neuropsychiatric and functional evaluation as well as structural imaging using voxel-based morphometry (VBM) to examine the grey matter subregions of the cerebellar lobules, vermis and crus. VBM analyses revealed: i) significant grey matter atrophy in the cerebellum across the whole ALS-bvFTD continuum; ii) atrophy predominantly of the superior cerebellum and crus in bvFTD patients, atrophy of the inferior cerebellum and vermis in ALS patients, while ALS-bvFTD patients had both patterns of atrophy. Post-hoc covariance analyses revealed that cognitive and neuropsychiatric symptoms were particularly associated with atrophy of the crus and superior lobule, while motor symptoms were more associated with atrophy of the inferior lobules. Taken together, these findings indicate an important role of the cerebellum in the ALS-bvFTD disease spectrum, with all three clinical phenotypes demonstrating specific patterns of subregional atrophy that associated with different symptomology

    Statistically Guided Synthesis of MoV- Based Mixed Oxide Catalysts for Ethane Partial Oxidation

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    The catalytic performance of Mo8V2Nb1-based mixed-oxide catalysts for ethane partial oxidation is highly sensitive to the doping of elements with redox and acid functionality. Specifically, control over product distributions to ethylene and acetic acid can be afforded via the specific pairing of redox elements (Pd, Ni, Ti) and acid elements (K, Cs, Te) and the levels at which these elements are doped. The redox element, acid element, redox/acid ratio, and dopant/host ratio were investigated using a three-level, four-factor factorial screening design to establish relationships between catalyst composition, structure, and product distribution for ethane partial oxidation. Results show that the balance between redox and acid functionality and overall dopant level is important for maximizing the formation of each product while maintaining the structural integrity of the host metal oxide. Overall, ethylene yield was maximized for a Mo8V2Nb1Ni0.0025Te0.5 composition, while acetic acid yield was maximized for a Mo8V2Nb1Ti0.005Te1 catalyst

    Проблемы увеличения продуктивности АПК в Украине и пути повышения его потенциала

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    Целью статьи является изучение причин снижения показателей продуктивности в агропромышленном комплексе и путей повышения продуктивности сельскохозяйственных культур

    Statistically Guided Synthesis of MoV-Based Mixed-Oxide Catalysts for Ethane Partial Oxidation

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    The catalytic performance of Mo8V2Nb1-based mixed-oxide catalysts for ethane partial oxidation is highly sensitive to the doping of elements with redox and acid functionality. Specifically, control over product distributions to ethylene and acetic acid can be afforded via the specific pairing of redox elements (Pd, Ni, Ti) and acid elements (K, Cs, Te) and the levels at which these elements are doped. The redox element, acid element, redox/acid ratio, and dopant/host ratio were investigated using a three-level, four-factor factorial screening design to establish relationships between catalyst composition, structure, and product distribution for ethane partial oxidation. Results show that the balance between redox and acid functionality and overall dopant level is important for maximizing the formation of each product while maintaining the structural integrity of the host metal oxide. Overall, ethylene yield was maximized for a Mo8V2Nb1Ni0.0025Te0.5 composition, while acetic acid yield was maximized for a Mo8V2Nb1Ti0.005Te1 catalyst
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