scholarly journals Architectural Diversity of Submarine Lobate Deposits

2021 ◽  
Vol 9 ◽  
Author(s):  
Tim R. McHargue ◽  
David M. Hodgson ◽  
Eitan Shelef
Keyword(s):  
Turbulent Flows ◽  
Deep Water ◽  
Relative Size ◽  
Transport Pathway ◽  
Branching Points ◽  
Channel Patterns ◽  
The Impact ◽  
Source Materials ◽  
Permeability Structure ◽  
Distributary Channel

Lobate deposits in deep-water settings are diverse in their depositional architecture but this diversity is under-represented in the literature. Diverse architectures result from multiple factors including source material, basin margin physiography, transport pathway, and depositional setting. In this contribution, we emphasize the impact of differing source materials related to differing delivery mechanisms and their influence on architecture, which is an important consideration in source-to-sink studies. Three well imaged subsurface lobate deposits are described that display three markedly different morphologies. All three lobate examples, two from intraslope settings offshore Nigeria and one from a basin-floor setting offshore Indonesia, are buried by less than 150 m of muddy sediment and are imaged with high resolution 3D reflection seismic data of similar quality and resolution. Distinctively different distributary channel patterns are present in two of the examples, and no comparable distributaries are imaged in a third example. Distributary channels are emphasized because they are objectively recognized and because they often represent elements of elevated fluid content within buried lobate deposits and thus influence permeability structure. We speculate that the different distributary channel patterns documented here resulted from different processes linked to source materials: 1) a lobate deposit that is pervasively channelized by many distributaries that have branched at numerous points is interpreted to result from comparatively mud-rich, stratified, turbulent flows; 2) an absence of distributaries in a lobate deposit is interpreted to result from collapse of mud-poor, turbulent flows remobilized from littoral drift; and 3) a lobate deposit with only a few, long, straight distributaries with few branching points is interpreted to be dominated by highly viscous flows (i.e., debris flows). We propose a conceptual model that illustrates the relationship between the proportion of mud in contributing flows and the relative size and runout distance of lobate deposits. We conclude that reconciling 3D seismic morphologies with outcrop observations of channels, scours, and amalgamation zones, and simple application of hierarchical schemes, is problematic. Furthermore, when characterizing unconfined deep-water deposits in the subsurface, multiple models with significant differences in predicted permeability structure should be considered.

R&D Heterogeneity and the Impact of R&D Subsidies*

2021 ◽  
Author(s):  
Sigurd M⊘lster Galaasen ◽  
Alfonso Irarrazabal
Keyword(s):  
Economic Impact ◽  
Growth Model ◽  
Relative Size ◽  
Schumpeterian Growth ◽  
Size Dependent ◽  
Investment Growth ◽  
The Impact ◽  
D Investment ◽  
Model Fits

Abstract This paper studies the determinants of R&D heterogeneity and the economic impact of R&D subsidies. We estimate a Schumpeterian growth model featuring firms with heterogeneous innovation efficiencies. The model fits well the R&D investment distribution, and the frequency and relative size of R&D performers. Using the model we study the impact of a Norwegian R&D reform targeting firms with R&D spending below a certain threshold. The size-dependent subsidy increases aggregate R&D investment by 11.7%, but reduces growth and welfare. In contrast, a uniform subsidy stimulates investment, growth and welfare.

The Effects of Turbulence Length Scale on the Performance of Piezoelectric Harvesters

2015 ◽  
Author(s):  
Yiannis Andreopoulos ◽  
Amir H. Danesh-Yazdi ◽  
Oleg Goushcha ◽  
Niell Elvin
Keyword(s):  
Turbulent Flows ◽  
Power Output ◽  
Isotropic Turbulence ◽  
Spatial Scales ◽  
Mechanical Energy ◽  
Relative Size ◽  
Analytical Description ◽  
Length Scale ◽  
Linear Effect ◽  
Turbulence Length

Turbulent flows carry mechanical energy distributed over a range of temporal and spatial scales and their interaction with a thin immersed piezoelectric beam results in a strain field which generates electrical charge. This energy harvesting method can be used for developing self-powered electronic devices such as flow sensors. In the present experimental work, various energy harvesters were placed in a turbulent boundary layer or inside a decaying flow field of homogeneous and isotropic turbulence. The role of large instantaneous turbulent structures in this rather complex fluid-structure interaction is discussed in interpreting the electrical output results. The forces acting on the vibrating beams have been measured dynamically and a theory has been developed which incorporates the effects of mean local velocity, turbulence intensity, the relative size of the beam’s length to the integral length scale of turbulence, the structural properties of the beam and the electrical properties of the active piezoelectric layer to provide reasonable estimates of the mean electrical power output. Experiments have been carried out in which these fluidic harvesters are immersed first in inhomogeneous turbulence like that encountered in boundary layers developing over solid walls and homogeneous and isotopic turbulence for which a simplified analytical description exists. It was found that there is a non-linear effect of turbulence length scales on the power output of the fluidic harvesters.

Energy or carbon? Exploring the relative size of universal zero carbon and zero energy design spaces

2018 ◽  
Vol 40 (3) ◽  
pp. 319-339 ◽  
Author(s):  
Anna Parkin ◽  
Manuel Herrera ◽  
David A Coley
Keyword(s):  
Design Space ◽  
Relative Size ◽  
Building Design ◽  
Zero Energy ◽  
Software Environment ◽  
Space Forms ◽  
Regulatory Frameworks ◽  
Regulatory Standards ◽  
Zero Carbon ◽  
The Impact

One aim of zero carbon, or zero energy, buildings is to help slow climate change. However, regulatory definitions frequently miss substantial emissions, for example ones associated with the materials the building is constructed from, thereby compromising this goal. Unfortunately, including such emissions might restrict the design space, reduce architectural freedom or greatly increase costs. This work presents a new framework for examining the problem. The zero carbon/energy design and regulatory space forms a sub-space of the hyper-volume enclosing all possible designs and regulatory frameworks. A new mathematical/software environment was developed which allows the size and shape of this sub-space to be investigated for the first time. Twenty-four million building design/regulatory standard combinations were modelled and assessed using a tree classification approach. It was found that a worldwide zero standard that includes embodied emissions is possible and is easier to achieve if a carbon rather than an energy metric is adopted, with the design space twice the size for a carbon metric. This result is important for the development of more encompassing regulations, and the novel methods developed applicable to other aspects of construction controlled by regulation where there is the desire to examine the impact of new regulations prior to legislation. Practical application: As energy standards become more strict, and given the growth in non-regulatory standards (such as Passivhaus), there is the need to study the potential impact of any element of a standard on the range of designs that can be built or the materials that can be used. This work sets out a general framework and method for doing this. The approach and results will be of interest to policy makers, but also to engineers and architects wondering what the key constraints to design the adoption of various philosophies to low energy/carbon standards might have within their work. For example, the implications of the building standard (or client) requiring embodied emissions to be included or the energy balance period for renewable generation to be monthly, not annual.

Estimating Zonal Flow Contributions in Deep Water Assets From Pressure and Temperature Data

2017 ◽  
Author(s):  
A. Rashid Hasan ◽  
Rayhana N. Sohel ◽  
Xiaowei Wang
Keyword(s):  
Turbulent Flows ◽  
Deep Water ◽  
Fluid Pressure ◽  
Zonal Flow ◽  
Temperature Data ◽  
Sensitivity Analyses ◽  
Momentum Balance ◽  
Flow Profile ◽  
Flowing Fluid ◽  
Energy And Momentum

Producing hydrocarbon from deep water assets is extremely challenging and expensive. A good estimate of rates from multiple pay zones is essential for well monitoring, surveillance, and workover decisions. Such information can be gleaned from flowing fluid pressure and temperature; deep-water wells are often well instrumented that offers such data on a continuous basis. In this study a model is presented that estimates zonal flow contributions based on energy and momentum balances. Kinetic and heat energy coming from the reservoir fluid to the production tubing is accounted for in the model. The momentum balance for wellbore takes into account differing flow profile in laminar and turbulent flows. In addition, when sandface temperature data are not available, a recently developed analytical model to estimate the effect of Joule-Thompson expansion on sandface temperature was used to estimate sandface temperature from reservoir temperature. The model developed can be applied to any reservoir with multiple pay zones and is especially useful for deep-water assets where production logging is practically impossible. Available field data for multiphase flow was used to validate the model. Sensitivity analyses were performed that showed accurate temperature data is essential for the model to estimate zonal contribution accurately.

scholarly journals Markovian inhomogeneous closures for Rossby waves and turbulence over topography

2018 ◽  
Vol 858 ◽  
pp. 45-70
Author(s):  
Jorgen S. Frederiksen ◽  
Terence J. O’Kane
Keyword(s):  
Turbulent Flows ◽  
Rossby Waves ◽  
Time History ◽  
Direct Interaction ◽  
Mean Flow ◽  
Current Time ◽  
Fluctuation Dissipation ◽  
Large Ensembles ◽  
Direct Interaction Approximation ◽  
The Impact

Manifestly Markovian closures for the interaction of two-dimensional inhomogeneous turbulent flows with Rossby waves and topography are formulated and compared with large ensembles of direct numerical simulations (DNS) on a generalized $\unicode[STIX]{x1D6FD}$-plane. Three versions of the Markovian inhomogeneous closure (MIC) are established from the quasi-diagonal direct interaction approximation (QDIA) theory by modifying the response function to a Markovian form and employing respectively the current-time (quasi-stationary) fluctuation dissipation theorem (FDT), the prior-time (non-stationary) FDT and the correlation FDT. Markov equations for the triad relaxation functions are derived that carry similar information to the time-history integrals of the non-Markovian QDIA closure but become relatively more efficient for long integrations. Far from equilibrium processes are studied, where the impact of a westerly mean flow on a conical mountain generates large-amplitude Rossby waves in a turbulent environment, over a period of 10 days. Excellent agreement between the evolved mean streamfunction and mean and transient kinetic energy spectra are found for the three versions of the MIC and two variants of the non-Markovian QDIA compared with an ensemble of 1800 DNS. In all cases mean Rossby wavetrain pattern correlations between the closures and the DNS ensemble are greater than 0.9998.

scholarly journals Regional characteristics of spring Asian dust and its impact on aerosol chemistry over northern China

2006 ◽  
Vol 6 (6) ◽  
pp. 12825-12864 ◽  
Author(s):  
Y. L. Sun ◽  
G. S. Zhuang ◽  
Z. F. Wang ◽  
Y. Wang ◽  
W. J. Zhang ◽  
...  
Keyword(s):  
Dust Storm ◽  
Fine Particles ◽  
Coastal Region ◽  
Northern China ◽  
Asian Dust ◽  
Aerosol Chemistry ◽  
Transport Pathway ◽  
Regional Characteristics ◽  
Source Regions ◽  
The Impact

Abstract. TSP and PM2.5 aerosol samples were synchronously collected at six sites along the transport pathway of dust storm from desert regions to coastal areas in the spring of 2004. The aerosol concentration and composition were measured to investigate the regional characteristics of spring Asian dust and its impact on aerosol chemistry over northern China. Based on the daily PM10 concentrations in 13 cities, the northern China could be divided into five regions, i.e., Northern Dust Region, Northeastern Dust Region, Western Dust Region, Inland Passing Region, and Coastal Region. Northern Dust Region was characterized by high content of Ca and Northeastern Dust Region was characterized by low one instead. Northeastern Dust Region was a relatively clean area with the lowest concentrations of pollutants and secondary ions among all sites. Inland Passing Region and Coastal Region showed high concentrations of pollutants, of which As and Pb in Inland Passing Region, and Na+, SO42− and NO3− in Coastal Region were the highest, respectively. The impact of dust on air quality was the greatest in the cities near source regions, and this impact decreased in the order of Yulin/Duolun > Beijing > Qingdao/Shanghai as the increase of transport distance. The spring Asian dust was inclined to affect the chemical components in coarse particles near source regions and those in fine particles in the cities far from source regions. Dust storm could mix significant quantities of pollutants on the pathway and carry them to the downwind cities or dilute the pollutants in the cities over northern China. Each dust episode corresponded to a low ratio of NO3−/SO42− with the lowest value appearing after the peak of dust storm. Asian dust played an important role in buffering and neutralizing the acidity of atmosphere in the cities over northern China, which could lead to the pH in the aerosols increase ~1 in spring.

scholarly journals Experimental Study of Drop Impact on Deep-Water Surface in the Presence of Wind

2018 ◽  
Vol 48 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Xinan Liu
Keyword(s):  
Deep Water ◽  
Water Surface ◽  
Water Drop ◽  
Threshold Value ◽  
Impact Angle ◽  
Drop Impact ◽  
Wind Speeds ◽  
Secondary Droplets ◽  
Low Wind Speeds ◽  
The Impact

AbstractThe effects of wind on the impact of a single water drop on a deep-water surface are studied experimentally in a wind tunnel. Experiments are performed by varying impacting drop diameters, ranging from 2.5 to 4.1 mm and wind speeds up to 6.7 m s−1. The sequence of splashing events that occurred during drop impacts is recorded with a backlit, cinematic shadowgraph technique. The experimental results show that for low wind speeds, an asymmetrical crown forms on the leeward of the periphery of the colliding region after the drop hits the water surface, while a wave swell forms on the windward. Secondary droplets are generated from the crown rim. For high wind speeds with large drop diameters, ligaments are generated from the crown rim on the leeward of the drop impact site. The ligaments grow, coalesce, and fragment into secondary droplets. It is found that both the drag force and surface tension play important roles in the evolution process of the ligaments. The nondimensional K number (K = WeOh−0.4, where We is the Webber number and Oh is the Ohnesorge number) is used to describe the splashing-deposition limit of drop impact. The threshold value of this K number changes with the wind velocity and/or drop impact angle.

Effects of channel engineering on flood dynamics along the middle and lower Rhône over the last two centuries.

2021 ◽  
Author(s):  
Mathieu Lucas ◽  
Michel Lang ◽  
Jérôme Le Coz ◽  
Benjamin Renard ◽  
Hervé Piegay
Keyword(s):  
Peak Discharge ◽  
Anthropogenic Pressures ◽  
Flood Peak ◽  
Area Of Interest ◽  
Channel Engineering ◽  
Indirect Consequence ◽  
Channel Patterns ◽  
Flood Dynamics ◽  
The Impact ◽  
Flood Waves

<p>The Rhône River has undergone many anthropogenic transformations to improve his navigability and produce hydroelectricity since the mid-19th century. From the longitudinal dikes of the 1850’s to the hydroelectric diversion schemes of the 1950’s and 1960’s, these structures had a direct impact on the channel geometry along the 300km of river course between Lyon (France) and the Mediterranean Sea. An indirect consequence could be a change in the flood dynamics along the channel course, caused by the simplification of the channel patterns and the floodplain accretion. This communication aims to assess the potential changes in the flood propagation along the middle and lower Rhône valley throughout a century of anthropogenic reconfigurations of the channel. The possible impact of these human pressures on the inundation risk and the attenuation of the flood peak discharge is also discussed. Through the use of digitized hydrometric data recorded since 1840 on multiple stream gauges of the Rhône river, a variety of floods of the same type and magnitude are selected. The oceanic flood types (as described by Pardé, 1925) that take their origin from heavy rainfalls upstream of the area of interest are preferred. Thus, complex flood waves due to floods from the lower Rhône valley tributaries are avoided, to keep the analysis as simple as possible. The flood travel time and the peak discharge attenuation of the selected events are compared over the years of channel transformations, permitting us to estimate the impact of anthropogenic pressures on the flood dynamics.</p>

Future Profitability, Operating Cash Flows, and Market Valuations Associated with Offshoring Arrangements of Technology Jobs

2009 ◽  
Vol 23 (2) ◽  
pp. 25-47 ◽  
Author(s):  
Kimberly Dunn ◽  
Mark Kohlbeck ◽  
Matthew Magilke
Keyword(s):  
Economies Of Scale ◽  
Value Relevance ◽  
Relative Size ◽  
Cash Flows ◽  
Labor Costs ◽  
Business Operations ◽  
Operating Cash Flows ◽  
Potential Benefits ◽  
Market Valuations ◽  
The Impact

ABSTRACT: We investigate profitability, operating cash flows, and value relevance associated with offshoring arrangements of technology-oriented jobs. Offshoring is the business practice of moving substantial portions of a firm's business operations (and jobs) to another country usually to take advantage of lower labor costs or other production factors in developing countries. Offshoring carries social costs as local jobs are lost which may limit realization of benefits. We find that firms that offshore technology-oriented jobs report greater earnings and operating cash flows following an offshoring event as the relative size of the offshoring arrangement increases. Consistent with these results, the market only values offshoring beyond the impact recognized in the financial statements for larger offshoring arrangements. A valuation discount actually exists for smaller offshoring arrangements suggesting either (1) costs exceed potential benefits or (2) the perception that benefits are only realized through economies of scale. We document both benefits and costs that are important for those firms considering offshoring arrangements and their stakeholders.

scholarly journals Network Design for Municipal Solid Waste Collection: A Case Study of the Nanjing Jiangbei New Area

2018 ◽  
Vol 15 (12) ◽  
pp. 2812 ◽  
Author(s):  
Jing Liang ◽  
Ming Liu
Keyword(s):  
Municipal Solid Waste ◽  
Network Design ◽  
Solid Waste ◽  
Relative Size ◽  
Service Level ◽  
Optimal Number ◽  
Mixed Integer ◽  
Proposed Model ◽  
The Impact ◽  
Operation Cost

Garbage collection is an important part of municipal engineering. An effective service network design can help to reduce the municipal operation cost and improve its service level. In this paper, we propose an optimization model for the network design of municipal solid waste (MSW) collection in the Nanjing Jiangbei new area. The problem was formulated as a mixed integer nonlinear programming (MINLP) model with an emphasis on minimizing the annual operation cost. The model simultaneously decides on the optimal number of refuse transfer stations (RTSs), determines the relative size and location for each RTS, allocates each community to a specific RTS, and finally identifies the annual operation cost and service level for the optimal scenario as well as other scenarios. A custom solution procedure which hybrids an enumeration rule and a genetic algorithm was designed to solve the proposed model. A sensitivity analysis was also conducted to illustrate the impact of changes in parameters on the optimality of the proposed model. Test results revealed that our model could provide tangible policy recommendations for managing the MSW collection.

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