scholarly journals Transport under advective trapping

2020 ◽  
Author(s):  
Juan J. Hidalgo ◽  
Insa Neuweiler ◽  
Marco Dentz
Keyword(s):  
Large Scale ◽  
Heterogeneous Media ◽  
Mathematical Formulation ◽  
Breakthrough Curves ◽  
Low Velocity ◽  
Spatial Geometry ◽  
The Impact ◽  
And Diffusion ◽  
Insight Into ◽  
Velocity Zone

<p>Advective trapping occurs when solutes enter a low velocity zone in the porous medium. Current multirate mass transfer (MRMT) models consider slow advection and diffusion but do not separate these processes, which makes parameterization difficult. Here we investigate the impact of advective trapping on transport in media consisting of isolated low permeability inclusions. Breakthrough curves show that effective transport changes from a streamtube model to genuine MRMT as the degree of disorder of the inclusion arrangement increases. We discuss the mathematical formulation in the MRMT and CTRW frameworks and the impact of the spatial geometry on the ergodicity and stationarity of large scale transport. These finding give new insight into transport into transport in highly heterogeneous media.</p>

scholarly journals Audio Mining: The Role of Vocal Tone in Persuasion

2021 ◽  
Author(s):  
Xin (Shane) Wang ◽  
Shijie Lu ◽  
X I Li ◽  
Mansur Khamitov ◽  
Neil Bendle
Keyword(s):  
Empirical Study ◽  
Large Scale ◽  
Controlled Experiments ◽  
The Core ◽  
Content Model ◽  
Stereotype Content ◽  
Key Indicators ◽  
The Impact ◽  
Insight Into

Abstract Persuasion success is often related to hard-to-measure characteristics, such as the way the persuader speaks. To examine how vocal tones impact persuasion in an online appeal, this research measures persuaders’ vocal tones in Kickstarter video pitches using novel audio mining technology. Connecting vocal tone dimensions with real-world funding outcomes offers insight into the impact of vocal tones on receivers’ actions. The core hypothesis of this paper is that a successful persuasion attempt is associated with vocal tones denoting (1) focus, (2) low stress, and (3) stable emotions. These three vocal tone dimensions—which are in line with the stereotype content model—matter because they allow receivers to make inferences about a persuader’s competence. The hypotheses are tested with a large-scale empirical study using Kickstarter data, which is then replicated in a different category. In addition, two controlled experiments provide evidence that perceptions of competence mediate the impact of the three vocal tones on persuasion attempt success. The results identify key indicators of persuasion attempt success and suggest a greater role for audio mining in academic consumer research.

CAN INFRASTRUCTURE DEVELOPMENT ALLEVIATE MULTIDIMENSIONAL POVERTY? — EVIDENCE FROM CHINA

2021 ◽  
pp. 1-34
Author(s):  
YONGBO GE ◽  
YUEXIAO ZHU ◽  
WENQIANG ZHANG ◽  
XIAORAN KONG
Keyword(s):  
Poverty Alleviation ◽  
Capital Accumulation ◽  
High Speed ◽  
Large Scale ◽  
Multidimensional Poverty ◽  
Infrastructure Development ◽  
Public Infrastructure ◽  
Regional Heterogeneity ◽  
The Impact ◽  
Insight Into

We investigate the impact of the construction of large-scale high-speed railways (HSRs) on regional multidimensional poverty in China. We find that the opening of HSRs can reduce this poverty indicator. This association is robust to a series of checks. Regarding the mechanisms, the opening of HSRs can improve regional accessibility, enhance local tourism, increase labor mobility and promote human capital accumulation, which alleviates multidimensional poverty. Further research indicates the regional heterogeneity of the effect. This research supplements poverty alleviation theory from the perspective of public infrastructure and offers insight into how multidimensional poverty arises and how it can be alleviated.

E-Business Adoption and its Impact on Performance

2010 ◽  
pp. 95-105
Author(s):  
Sabah Abdullah Al-Somali ◽  
Ben Clegg ◽  
Roya Gholami
Keyword(s):  
Business Performance ◽  
Large Scale ◽  
Business Processes ◽  
Business Environment ◽  
Scale Transformation ◽  
Business Partners ◽  
Business Operations ◽  
Multi Phase ◽  
And Diffusion ◽  
Insight Into

Organizations today face intense competitive and economic pressures leading to large scale transformation of existing business operations and transactions. In addition, organizations have adopted automated business processes to deal with partners and customers. E-business diffusion is a multi-phase process, moving from initiation through to routinisation and an insight into the adoption processes helps organizations to adopt e-business more effectively. It is imperative that organizations effectively manage the e-business environment, and all associated changes to accommodate the changing relationships with customers and business partners and more importantly, to improve performance. This chapter discusses the process of e-business implementation, usage and diffusion (routinisation stage) on business performance.

The diffusing-velocity random walk: Capturing the interplay of diffusion and heterogeneous advection within a spatial-Markov framework

2021 ◽  
Author(s):  
Tomas Aquino ◽  
Tanguy Le Borgne
Keyword(s):  
Shear Rate ◽  
Correlation Length ◽  
Scaling Laws ◽  
Heterogeneous Media ◽  
Tracer Particle ◽  
Diffusive Dynamics ◽  
Temporal Process ◽  
The Impact ◽  
And Diffusion

<p>The spatial distribution of a solute undergoing advection and diffusion is impacted by the velocity variability sampled by tracer particles. In spatially structured velocity fields, such as porous medium flows, Lagrangian velocities along streamlines are often characterized by a well-defined correlation length and can thus be described by spatial-Markov processes. Diffusion, on the other hand, is generally modeled as a temporal process, making it challenging to capture advective and diffusive dynamics in a single framework. In order to address this limitation, we have developed a description of transport based on a spatial-Markov velocity process along Lagrangian particle trajectories, incorporating the effect of diffusion as a local averaging process in velocity space. The impact of flow structure on this diffusive averaging is quantified through an effective shear rate. The latter is fully determined by the point statistics of velocity magnitudes together with characteristic longitudinal and transverse lengthscales associated with the flow field. For infinite longitudinal correlation length, our framework recovers Taylor dispersion, and in the absence of diffusion it reduces to a standard spatial-Markov velocity model. This novel framework allows us to derive dynamical equations governing the evolution of particle position and velocity, from which we obtain scaling laws for the dependence of longitudinal dispersion on Péclet number. Our results provide new insights into the role of shear and diffusion on dispersion processes in heterogeneous media.</p><p>In this presentation, I propose to discuss: (i) Spatial-Markov models and the modeling of diffusion as a spatial rather than temporal process; (ii) The concept of the effective shear rate and its role in the diffusive dynamics of tracer particle velocities; (iii) The role of transverse diffusion and its interplay with velocity heterogeneity on longitudinal solute dispersion.</p>

scholarly journals Relationship Between Matrix Cracking and Delamination in CFRP Cross-Ply Laminates Subjected to Low Velocity Impact

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3990 ◽  
Author(s):  
Riming Tan ◽  
Jifeng Xu ◽  
Wei Sun ◽  
Zhun Liu ◽  
Zhidong Guan ◽  
...  
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Matrix Cracks ◽  
Impact Location ◽  
The Matrix ◽  
The Impact

The effect of matrix cracking on the delamination morphology inside carbon fiber reinforced plastics (CFRP) laminates during low-velocity impact (LVI) is an open question. In this paper, the relationship between matrix cracking and delamination is studied by using cross-ply laminates. Several methods, including micrograph, C-scan, and visual inspection, were adopted to characterize the damage after LVI experiments. Based on the experimental results, finite element (FE) models were established to analyze the damage mechanisms. The matrix cracking was predicted by the extended finite element method (XFEM) and the Puck criteria, while the delamination was modeled by cohesive elements. It was revealed that the matrix crack in the bottom ply not only promoted the outward propagation of delamination but also contributed to the narrow delamination beneath the impact location. Multiple matrix cracks occurred in the middle ply. The ones close to the plate center initiated the delamination and prevented large-scale delamination beneath the impact location. For the cracks that were far away, no significant effect on delamination was found. In conclusion, the stress redistribution caused by the crack opening determines the delamination.

Study on the Low-Velocity Impact Behavior of CFRP with Nanoclay-Filled Epoxy Matrix

2008 ◽  
Vol 47-50 ◽  
pp. 1205-1208 ◽  
Author(s):  
Iqbal Kosar ◽  
Khan Shafi Ullah ◽  
Jang Kyo Kim ◽  
Arshad Munir
Keyword(s):  
Impact Damage ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Damage Resistance ◽  
Velocity Impact ◽  
Compression After Impact ◽  
The Impact ◽  
Carbon Fiber Epoxy ◽  
Insight Into

The influence of nanoclay on the impact damage resistance of carbon fiber-epoxy (CFRP) composites has been investigated using the low-velocity impact and compression after impact tests. The load-energy vs time relations were analyzed to gain insight into the damage behaviors of the materials. Compression-after-impact (CAI) test was performed to measure the residual compressive strength. The CFRPs containing organoclay brought about a significant improvement in impact damage resistance and damage tolerance. The composites containing organoclay exhibited an enhanced energy absorption capability with less damage areas and higher CAI strengths compared to those made from neat epoxy. A 3wt% phr was shown to be an optimal content with the highest damage resistance.

Anomalous dispersion in chemically heterogeneous media induced by long-range disorder correlation

2012 ◽  
Vol 695 ◽  
pp. 366-389 ◽  
Author(s):  
D. Bolster ◽  
M. Dentz
Keyword(s):  
Random Walk ◽  
Long Range ◽  
Large Scale ◽  
Heterogeneous Media ◽  
Stochastic Modelling ◽  
Anomalous Dispersion ◽  
Retardation Factor ◽  
The Family ◽  
Spatially Varying ◽  
The Impact

AbstractWe study transport in an idealized porous medium characterized by a spatially varying retardation factor, which models linear instantaneous chemical adsorption of a solute. Using a stochastic modelling approach, we study the impact of disorder correlation on the large-scale dispersion behaviour. We consider short, long-range and intermediate-range disorder correlations, and demonstrate that (truncated) power-law correlation causes anomalous dispersion, even in the presence of weak heterogeneity. We identify different preasymptotic and asymptotic regimes of anomalous dispersion that shed new light on the disorder and local-scale transport mechanisms leading to non-Fickian behaviour. The analytical results are complemented by numerical random walk particle tracking simulations, which are found to be in good agreement with the derived dispersion behaviour. We conclude the paper by deriving an effective transport equation for this system, which can be shown to be tied to the family of continuous-time random walk models.

scholarly journals Charlotte Froese Fischer—Her Work and Her Impact

Atoms ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 107
Author(s):  
Alan Hibbert
Keyword(s):  
Atomic Structure ◽  
Large Scale ◽  
Computer Programs ◽  
Research Community ◽  
Structure Theory ◽  
90Th Birthday ◽  
The Impact ◽  
Insight Into

Charlotte Froese Fischer has been at the forefront of research in atomic structure theory for over 60 years. She has developed many of the methods currently used by researchers and has written associated computer programs which have been published and hence made accessible to the research community. Throughout her career, she has consistently encouraged and mentored young scientists, enabling them to embark on independent careers of their own. This article provides an overview of the methods and codes she has developed, some large-scale calculations she has undertaken, and some insight into the impact she has had on young scientists, and the leadership she continues to show as she reaches her 90th birthday.

Links of planetary energetics to moon size, orbit, and planet spin: A new mechanism for plate tectonics

2022 ◽  
Author(s):  
Anne M. Hofmeister ◽  
Robert E. Criss ◽  
Everett M. Criss
Keyword(s):  
Plate Tectonics ◽  
Large Scale ◽  
Low Velocity ◽  
Radiogenic Heat ◽  
Plate Motions ◽  
Low Velocity Zone ◽  
Ocean Ridges ◽  
Inertial Response ◽  
Rocky Planets ◽  
Velocity Zone

ABSTRACT Lateral accelerations require lateral forces. We propose that force imbalances in the unique Earth-Moon-Sun system cause large-scale, cooperative tectonic motions. The solar gravitational pull on the Moon, being 2.2× terrestrial pull, causes lunar drift, orbital elongation, and an ~1000 km radial monthly excursion of the Earth-Moon barycenter inside Earth’s mantle. Earth’s spin superimposes an approximately longitudinal 24 h circuit of the barycenter. Because the oscillating barycenter lies 3500–5500 km from the geocenter, Earth’s tangential orbital acceleration and solar pull are imbalanced. Near-surface motions are enabled by a weak low-velocity zone underlying the cold, brittle lithosphere: The thermal states of both layers result from leakage of Earth’s internal radiogenic heat to space. Concomitantly, stress induced by spin cracks the lithosphere in a classic X-pattern, creating mid-ocean ridges and plate segments. The inertial response of our high-spin planet with its low-velocity zone is ~10 cm yr–1 westward drift of the entire lithosphere, which largely dictates plate motions. The thermal profile causes sinking plates to thin and disappear by depths of ~200–660 km, depending on angle and speed. Cyclical stresses are effective agents of failure, thereby adding asymmetry to plate motions. A comparison of rocky planets shows that the presence and longevity of volcanism and tectonism depend on the particular combination of moon size, moon orbital orientation, proximity to the Sun, and rates of body spin and cooling. Earth is the only rocky planet with all the factors needed for plate tectonics.

scholarly journals The timing of one-shot interventions for epidemic control

2020 ◽  
Author(s):  
Francesco Di Lauro ◽  
István Z. Kiss ◽  
Joel C. Miller
Keyword(s):  
Large Scale ◽  
Short Term ◽  
Early Success ◽  
Large Peak ◽  
Two Peaks ◽  
The Impact ◽  
Insight Into ◽  
Policy Question ◽  
Comparable Size

AbstractThe apparent early success in China’s large-scale intervention to control the COVID-19 epidemic has led to interest in whether other countries can replicate it as well as concerns about a resurgence of the epidemic if or when China relaxes the interventions. In this paper we look at the impact of a single short-term intervention on an epidemic. We see that if an intervention cannot be sustained long-term, it has the greatest impact if it is imposed once infection levels have become large enough that there is an appreciable number of infections present. For minimising the total number infected it should start close to the peak so that there is no rebound once the intervention is stopped, while to minimise the peak prevalence, it should start earlier, allowing two peaks of comparable size rather than one very large peak. In populations with distinct subgroups, synchronized interventions are less effective than targeting the interventions in each sub-population separately.We do not attempt to clearly determine what makes an intervention sustainable or not. We believe that is a policy question. If an intervention is sustainable, it should be kept in place. Our intent is to offer insight into how best to time an intervention whose impact on society is too great to maintain.

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