Large scale and cost effective generation of 3D self-supporting oxide nanowire architectures by a top-down and bottom-up combined approach

RSC Advances ◽  
2016 ◽  
Vol 6 (51) ◽  
pp. 45923-45930 ◽  
Author(s):  
Peixun Fan ◽  
Minlin Zhong ◽  
Benfeng Bai ◽  
Guofan Jin ◽  
Hongjun Zhang
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Combined Approach ◽  
Top Down ◽  
Bottom Up ◽  
Effective Generation

Large-scale and cost-effective generation of desired 3D self-supporting macro–micronano-nanowire architectures is realized by a top-down and bottom-up combined approach.

“Forward to David the Builder!” Georgia's (re)turn to language-centered nationalism

2016 ◽  
Vol 44 (4) ◽  
pp. 522-542 ◽  
Author(s):  
Christofer Berglund
Keyword(s):  
Large Scale ◽  
Nation Building ◽  
The State ◽  
Top Down ◽  
Bottom Up ◽  
The Past ◽  
Building Project ◽  
The Rose ◽  
State Language

After the Rose Revolution, President Saakashvili tried to move away from the exclusionary nationalism of the past, which had poisoned relations between Georgians and their Armenian and Azerbaijani compatriots. His government instead sought to foster an inclusionary nationalism, wherein belonging was contingent upon speaking the state language and all Georgian speakers, irrespective of origin, were to be equals. This article examines this nation-building project from a top-down and bottom-up lens. I first argue that state officials took rigorous steps to signal that Georgian-speaking minorities were part of the national fabric, but failed to abolish religious and historical barriers to their inclusion. I next utilize a large-scale, matched-guise experiment (n= 792) to explore if adolescent Georgians ostracize Georgian-speaking minorities or embrace them as their peers. I find that the upcoming generation of Georgians harbor attitudes in line with Saakashvili's language-centered nationalism, and that current Georgian nationalism therefore is more inclusionary than previous research, or Georgia's tumultuous past, would lead us to believe.

scholarly journals Uncertainty, sensitivity analysis and the role of data based mechanistic modeling in hydrology

2007 ◽  
Vol 11 (4) ◽  
pp. 1249-1266 ◽  
Author(s):  
M. Ratto ◽  
P. C. Young ◽  
R. Romanowicz ◽  
F. Pappenberger ◽  
A. Saltelli ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Uncertainty Estimation ◽  
Mechanistic Modeling ◽  
Structure Identification ◽  
Catchment Management ◽  
Effective Rainfall ◽  
Combined Approach ◽  
Top Down ◽  
Bottom Up ◽  
Modelling Methodology

Abstract. In this paper, we discuss a joint approach to calibration and uncertainty estimation for hydrologic systems that combines a top-down, data-based mechanistic (DBM) modelling methodology; and a bottom-up, reductionist modelling methodology. The combined approach is applied to the modelling of the River Hodder catchment in North-West England. The top-down DBM model provides a well identified, statistically sound yet physically meaningful description of the rainfall-flow data, revealing important characteristics of the catchment-scale response, such as the nature of the effective rainfall nonlinearity and the partitioning of the effective rainfall into different flow pathways. These characteristics are defined inductively from the data without prior assumptions about the model structure, other than it is within the generic class of nonlinear differential-delay equations. The bottom-up modelling is developed using the TOPMODEL, whose structure is assumed a priori and is evaluated by global sensitivity analysis (GSA) in order to specify the most sensitive and important parameters. The subsequent exercises in calibration and validation, performed with Generalized Likelihood Uncertainty Estimation (GLUE), are carried out in the light of the GSA and DBM analyses. This allows for the pre-calibration of the the priors used for GLUE, in order to eliminate dynamical features of the TOPMODEL that have little effect on the model output and would be rejected at the structure identification phase of the DBM modelling analysis. In this way, the elements of meaningful subjectivity in the GLUE approach, which allow the modeler to interact in the modelling process by constraining the model to have a specific form prior to calibration, are combined with other more objective, data-based benchmarks for the final uncertainty estimation. GSA plays a major role in building a bridge between the hypothetico-deductive (bottom-up) and inductive (top-down) approaches and helps to improve the calibration of mechanistic hydrological models, making their properties more transparent. It also helps to highlight possible mis-specification problems, if these are identified. The results of the exercise show that the two modelling methodologies have good synergy; combining well to produce a complete joint modelling approach that has the kinds of checks-and-balances required in practical data-based modelling of rainfall-flow systems. Such a combined approach also produces models that are suitable for different kinds of application. As such, the DBM model considered in the paper is developed specifically as a vehicle for flow and flood forecasting (although the generality of DBM modelling means that a simulation version of the model could be developed if required); while TOPMODEL, suitably calibrated (and perhaps modified) in the light of the DBM and GSA results, immediately provides a simulation model with a variety of potential applications, in areas such as catchment management and planning.

scholarly journals Climate Dialog, Climate Action: Can Democracy Do the Job?

2021 ◽  
Author(s):  
Fred Young Phillips ◽  
LaVonne Reimer ◽  
Rebecca Turner
Keyword(s):  
Large Scale ◽  
Global Climate ◽  
Environmental Issues ◽  
Top Down ◽  
Bottom Up ◽  
Psychological Mechanisms ◽  
Ipcc Report ◽  
Climate Action

The latest IPCC report forcefully states that immediate, decisive, and large-scale actions are needed to avert climate catastrophe. This essay presumes that democratic governments are best and most desirably positioned to take these actions. Yet in the countries most pivotal to global climate, significant voting blocs are uninterested in environmental issues. The essay urges adding bottom-up dialog between environmental and anti-environmental voters, to current and future top-down technocratic “solutions.” To make this combination result in a unified pro-environment electorate, we must understand: religious objections to environmentalism; the capital-vs.-knowledge strife that slows polluting corporations’ green transitions; and the psychological mechanisms that can make inter-group dialog fruitful.

scholarly journals Emissions of Carbon Tetrachloride (CCl<sub>4</sub>) from Europe

2016 ◽  
Author(s):  
Francesco Graziosi ◽  
Jgor Arduini ◽  
Paolo Bonasoni ◽  
Francesco Furlani ◽  
Umberto Giostra ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Large Scale ◽  
Stratospheric Ozone ◽  
Montreal Protocol ◽  
Scale Production ◽  
Top Down ◽  
Significant Discrepancy ◽  
Bottom Up ◽  
Atmospheric Observations ◽  
Global Emissions

Abstract. Carbon tetrachloride (CCl4) is a long-lived radiatively-active compound able to destroy stratospheric ozone. Due to its inclusion in the Montreal Protocol on Substances that Deplete the Ozone Layer, the last two decades have seen a sharp decrease in its large scale emissive use with a consequent decline of its atmospheric mole fractions. However, the Montreal Protocol restrictions do not apply to the use of carbon tetrachloride as feedstock for the production of other chemicals, implying the risk of fugitive emissions from the industry sector. The occurrence of such unintended emissions is suggested by a significant discrepancy between global emissions as derived by reported production and feedstock usage (bottom-up emissions), and those based on atmospheric observations (top-down emissions). In order to better constrain the atmospheric budget of carbon tetrachloride, several studies based on a combination of atmospheric observations and inverse modelling have been conducted in recent years in various regions of the world. This study is focused on the European scale and based on long-term high-frequency observations at three European sites, combined with a Bayesian inversion methodology. We estimated that average European emissions for 2006–2014 were 2.3 (± 0.8) Gg yr−1, with an average decreasing trend of 7.3 % per year. Our analysis identified France as the main source of emissions over the whole study period, with an average contribution to total European emissions of 25 %. The inversion was also able to allow the localisation of emission "hot-spots" in the domain, with major source areas in Southern France, Central England (UK) and Benelux (Belgium, The Netherlands, Luxembourg), where most of industrial scale production of basic organic chemicals are located. According to our results, European emissions correspond to 4.0 % of global emissions for 2006–2012. Together with other regional studies, our results allow a better constraint of the global budget of carbon tetrachloride and a better quantification of the gap between top-down and bottom-up estimates.

Distributional semantics insights on agentive suffix rivalry in French

2021 ◽  
Vol 14 (3) ◽  
pp. 354-391
Author(s):  
Richard Huyghe ◽  
Marine Wauquier
Keyword(s):  
Quantitative Analysis ◽  
Large Scale ◽  
Statistical Analyses ◽  
Distributional Semantics ◽  
Top Down ◽  
Bottom Up ◽  
Distributional Properties ◽  
Large Scale Study ◽  
New Perspective

The formation of French agent nouns (ANs) involves a large variety of morphological constructions, and particularly of suffixes. In this study, we focus on the semantic counterpart of agentive suffix diversity and investigate whether the morphological variety of ANs correlates with different agentive subtypes. We adopt a distributional semantics approach and combine manual, computational and statistical analyses applied to French ANs ending in -aire, -ant, -eur, -ien, -ier and -iste. Our methodology allows for a large-scale study of ANs and involves both top-down and bottom-up procedures. We first characterize agentive suffixes with respect to their morphosemantic and distributional properties, outlining their specificities and similarities. Then we automatically cluster ANs into distributionally relevant subsets and examine their properties. Based on quantitative analysis, our study provides a new perspective on agentive suffix rivalry in French that both confirms existing claims and sheds light on previously unseen phenomena.

Construction of a silicon-based solid state quantum computer

2001 ◽  
Vol 1 (Special) ◽  
pp. 82-95
Author(s):  
A.S. Dzurak ◽  
M.Y. Simmons ◽  
A.R. Hamilton ◽  
R.G. Clark ◽  
R. Brenner ◽  
...  
Keyword(s):  
Large Scale ◽  
Quantum Computer ◽  
Atomic Scale ◽  
Single Electron Transistor ◽  
Epitaxial Silicon ◽  
Top Down ◽  
Bottom Up ◽  
Near Term ◽  
Silicon Based ◽  
Coincidence Measurements

We discuss progress towards the fabrication and demonstration of a prototype silicon-based quantum computer. The devices are based on a precise array of 31P dopants embedded in 28Si. Fabrication is being pursued via two complementary pathways – a ‘top-down’ approach for near-term production of few-qubit demonstration devices and a ‘bottom-up’ approach for large-scale qubit arrays. The ‘top-down’ approach employs ion implantation through a multi-layer resist structure which serves to accurately register the donors to metal control gates and single-electron transistor (SET) read-out devices. In contrast the ‘bottom-up’ approach uses STM lithography and epitaxial silicon overgrowth to construct devices at an atomic scale. Techniques for qubit read-out, which utilise coincidence measurements on novel twin-SET devices, are also presented.

scholarly journals Ascending–descending and direct–inverse cascades of Reynolds stresses in turbulent Couette flow

2021 ◽  
Vol 930 ◽  
Author(s):  
Alessandro Chiarini ◽  
Mariadebora Mauriello ◽  
Davide Gatti ◽  
Maurizio Quadrio
Keyword(s):  
Couette Flow ◽  
Large Scale ◽  
Normal Component ◽  
Physical Space ◽  
Limited Range ◽  
Order Structure ◽  
Reynolds Stresses ◽  
Top Down ◽  
Bottom Up ◽  
Near Wall

The interaction between small- and large-scale structures and the coexisting bottom-up and top-down processes are studied in a turbulent plane Couette flow, where space-filling longitudinal rolls appear at relatively low values of the Reynolds number $Re$ . A direct numerical simulation database at $Re_\tau =101$ is built to replicate the highest $Re$ considered in recent experimental work by Kawata & Alfredsson (Phys. Rev. Lett., vol. 120, 2018, 244501). Our study is based on the exact budget equations for the second-order structure function tensor $\left \langle {\delta u_i \delta u_j} \right \rangle$ , i.e. the anisotropic generalized Kolmogorov equations (AGKE). The AGKE study production, redistribution, transport and dissipation of every Reynolds stress tensor component, considering simultaneously the physical space and the space of scales, and properly define the concept of scale in the inhomogeneous wall-normal direction. We show how the large-scale energy-containing motions are involved in the production and redistribution of the turbulent fluctuations. Both bottom-up and top-down interactions occur, and the same is true for direct and inverse cascading. The wall-parallel components $\left \langle {\delta u \delta u} \right \rangle$ and $\left \langle {\delta w \delta w} \right \rangle$ show that both small and large near-wall scales feed the large scales away from the wall. The wall-normal component $\left \langle {\delta v \delta v} \right \rangle$ is different, and shows a dominant top-down dynamics, being produced via pressure-strain redistribution away from the wall and transferred towards near-wall larger scales via an inverse cascade. The off-diagonal component shows a top-down interaction, with both direct and inverse cascades, albeit the latter takes place within a limited range of scales.

scholarly journals Bottom-up sensory processing can decrease activity and functional connectivity in the default mode like network in rats

2018 ◽  
Author(s):  
Rukun Hinz ◽  
Lore M. B. Peeters ◽  
Disha Shah ◽  
Stephan Missault ◽  
Michaël Belloy ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Sensory Processing ◽  
Large Scale ◽  
Visual Stimulation ◽  
Block Design ◽  
Brain State ◽  
Top Down ◽  
Similar Reduction ◽  
Bottom Up ◽  
Default Mode

AbstractThe default mode network is a large-scale brain network that is active during rest and internally focused states and deactivates as well as desynchronizes during externally oriented (top-down) attention demanding cognitive tasks. However, it is not sufficiently understood if unpredicted salient stimuli, able to trigger bottom-up attentional processes, could also result in similar reduction of activity and functional connectivity in the DMN. In this study, we investigated whether bottom-up sensory processing could influence the default mode like network (DMLN) in rats. DMLN activity was examined using block-design visual functional magnetic resonance imaging (fMRI) while its synchronization was investigated by comparing functional connectivity during a resting versus a continuously stimulated brain state by unpredicted light flashes. We demonstrated that activity in DMLN regions was decreased during visual stimulus blocks and increased during blanks. Furthermore, decreased inter-network functional connectivity between the DMLN and visual networks as well as decreased intra-network functional connectivity within the DMLN was observed during the continuous visual stimulation. These results suggest that triggering of bottom-up attention mechanisms in anesthetized rats can lead to a cascade similar to top-down orienting of attention in humans and is able to deactivate and desynchronize the DMLN.

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