Research on Multi-scene and Multi-station Fusion Mode Based on Layered Theory of Energy Internet

Multi-station integration is a new form of business in the development of energy Internet and a brand new practice of power iot. It is an innovative form that strengthens the interaction between charge and storage of source network on both sides of energy supply and demand, and enhances the flexibility of power grid by taking substation, energy storage station, distributed energy station and other resources as the core. However, there is not a set of construction mode that can guide implementation, copy and popularize. Therefore, guided by the existing construction practice of multi-station fusion in China and combined with multi-user scenarios, this paper studies the multi-station fusion mode, proposes a multi-station fusion planning system based on EIST theory, gives the fusion mode under different business scenarios, and synchronously constructs a new ecological business chain with multi-station fusion as the core. It aims to make full use of the innate advantages of substation in energy flow convergence, realize the “integration of energy flow, business flow and data flow”, comprehensively support the transformation of digital power grid, and practice the national development strategy of “digital economy” and “digital China”.

Mathematical Model of Macromolecular Drug Transport in a Partially Liquefied Vitreous Humor

The purpose of this study is to investigate the effect of partial liquefaction (due to ageing) of the vitreous humor on the transport of ocular drugs. In our model, the gel part of the vitreous is treated as a Darcy-type porous medium. A spherical region within the porous part of vitreous is in a liquid state which, for computational purposes, is also treated as a porous medium but with a much higher permeability. Using the finite element method, a time-dependent, three-dimensional model has been developed to computationally simulate (using the Petrov-Galerkin method) the transport of intravitreally injected macromolecules where both convection and diffusion are present. From a fluid physics and transport phenomena perspective, the results show many interesting features. For pressure-driven flow across the vitreous, the flow streamlines converge into the liquefied region as the flow seeks the fastest path of travel. Furthermore, as expected, with increased level of liquefaction, the overall flow rate increases for a given pressure drop. We have quantified this effect for various geometrical considerations. The flow convergence into the liquefied region has important implication for convective transport. One effect is the clear diversion of the drug as it reaches the liquefied region. In some instances, the entry point of the drug in the retinal region gets slightly shifted due to liquefaction. While the model has many approximations and assumptions, the focus is illustrating the effect of liquefaction as one of the building blocks towards a fully comprehensive model.

181 Impact of leaflet-tethering angle correction on the assessment of tricuspid regurgitation severity using the PISA method

Aims Severe tricuspid regurgitation (TR) is associated with excess mortality and morbidity. Therefore, accurate assessment of TR severity is pivotal. In clinical routine, the calculation of the effective regurgitant orifice area (EROA) and the regurgitant volume (RVol) using flow convergence method (PISA) by echocardiography are among the recommended parameters to define TR severity. However, the distortion of the proximal convergence zone related to the extent of valve leaflet tethering may result in smaller PISA radius and in underestimation of TR severity. Correcting for the angle of the leaflet tethering could reduce errors due to geometric assumption of a flat valvular plane and improve the accuracy of the calculations. The aims of our study were: (1) to evaluate whether taking into account the extent of leaflet tethering by applying the angle correction (AC) in the PISA formula improves the accuracy of the quantitative assessment of TR severity; (2) to assess the potential clinical impact of AC. Methods and results Forty-one patients with functional TR (73.5 ± 11.8 years, 51% men, 36% sinus rhythm, 17% severe), underwent 2D and 3D echocardiography. We compared the RVol obtained by volumetric method (as reference) with the RVol by PISA with and without AC. TR RVol by volumetric method was calculated as: total RV stroke volume (RV SV)–left ventricular forward SV (LV SV), where RV SV was obtained by subtracting the end-systolic from end-diastolic RV volume measured by 3D echocardiography and LV SV was calculated by multiplying LV outflow area by velocity time integral (VTI). TR RVol by PISA was calculated as EROA × VTI TR. Uncorrected EROA was calculated using the formula: 6.28 r2 × Va/PeakV TR (r—PISA radius, Va, aliasing velocity, PeakV TR—TR peak velocity). The corrected EROA accounting for the PISA geometric distortion by leaflet tethering angle (α) was calculated as: 6.28 r2 × Va (α/180)/PeakV TR (PISAAC), where α was measured using a protractor generated by dedicated software. PISA radius and angle were 5.5 ± 1.97 mm and 211.2° ± 13.6°, respectively. Application of AC to PISA method resulted in larger EROA and RVol (0.34 ± 0.38 cm2 vs. 0.24 ± 0.24 cm2 and, 25.2 ± 19.3 ml vs. 18.6 ± 13.1 ml, respectively). The percentage change in EROAAC was over 40%. When compared to the volumetric method, RVol by corrected PISA method was significantly closer and correlated (bias −3.95 ml, LOA ± 6.41 ml, r = 0.987; P < 0.001) than the conventional PISA without AC (bias −10.5 ml, LOA ± 15 ml, r = 0.975). Angle correction resulted in a change of TR severity in 32% of cases and in a greater concordance of TR severity grade with the volumetric method (75%, 31/41 with AC vs. 52%, 22/41 without AC). Conclusions Angle-corrected PISA method that accounts for the extent of the leaflet tethering in TR provided significantly larger TR RVol that were closely correlated with the volumetric RVol by 3D echocardiography. A simple geometric angle correction of the proximal flow with PISA method reclassified up to one-third of patients with functional TR.

Impact of Data Processing and DTM Resolution on Determining of Small Erosional Landforms

Small erosional landforms are characterised by a dynamics closely related to the occurrence and changes in precipitation and water flowing down the slopes. Triggered by water, the erosion processes are controlled by the other environmental conditions like slope gradient, lithology, land cover and land use. Studying the changes in the topography gives information about the spatiotemporal dynamics of erosion and can contribute to a more effective assessment of erosion susceptibility and mitigation measures at the earliest stage of the process development. Usually in the initial stages, the changes in the topography are hardly noticeable and using high resolution digital terrain models (DTMs) is of high importance. In this relation, the aim of the current research is to determine to what extent the resolution of the models influences the results of delineating the flow lines, rills and gullies. For this purpose, a terrain survey was carried out and data was acquired by UAS (uncrewed aerial system) DJI Phantom 4RTK. DTMs in horizontal resolution of 0.05, 0.1, 0.2, 0.5 and 1 m are created and analysed. Special attention is given to the analysis of surface curvature as an indicator for flow convergence and divergence. The research is done on a slope area covered mainly by grass and some rare bushes and trees. Despite the observed variations, the results show a general trend of decrease in the flow length with decreasing DTMs resolution. Considering the plan curvature and concave areas, the differences are smallest between the models with cell size 0.1 and 0.2 m.

The role of mass-transport complexes (MTCs) in the initiation and evolution of submarine canyons

The offshore area of the Otway Basin, located within the SE continental margin of Australia, is dominated by a multibranched canyon system where submarine mass-transport complexes (MTCs) are widely distributed. We integrate high-resolution multi-beam bathymetric and seismic reflection data to investigate the importance of regionally distributed MTCs in dictating the evolution of canyon systems. We interpret three regionally distributed MTCs that fail retrogressively and affect almost 70% of the study area. Within the MTCs, we observed seven canyons that initiated from the continental shelf edge and extended to the abyssal plain. Although these canyons share common regional tectonics and oceanography, the scales, morphology, and distribution are distinctly different. This is devoted to the presence of failure-related scarps (i.e. headwall and sidewall scarps) that control the initiation and formation of the canyons. The retrogressive failure mechanisms of MTCs have created a series of the headwall and lateral scarps on the continental shelf and slope regions. In the continental shelf, where terrestrial input (i.e. fluvial systems) is absent, the origin of the canyons is related to the local failure events and the contour current activities occurring near the pre-existing, massive headwall scarps (c. 120 m high, 3km long). The occurrence of these local failures has provided the necessary sediment input for subsequent gravity-driven, downslope sediment flows. In the continental slope region, the widespread scarps can capture gravity flows initiated from the continental shelf, developing an area of flow convergence, which greatly widens and deepens the canyon system. The gradual diversion and convergence through MTCs related scarps have facilitated the canyon confluence process, which has fundamentally changed the canyoning process. Thus, we conclude that the retrogressive failure mechanism of MTCs has a direct contribution to the initiation, distribution, and evolution of the canyons, especially in areas where fluvial input is missing. Moreover, the retrogressive failure mechanism is responsible for the canyon deepening and confluence process, which can greatly facilitate the delivery of sediment into deep oceans.

The implications of Industry 4.0 on supply chains amid the COVID-19 pandemic: a systematic review

Background: COVID-19 has caused significant disruptions in supply chains. It has increased the demand for products and decreased the supply of raw materials. This has interrupted many production processes. The emerging technologies of Industry 4.0 have the potential to streamline supply chains by improving time-sensitive customized solutions during this emergency. Purpose: This research examines the effects of the epidemic on supply chains and how these effects are reduced through Industry 4.0 technology. Design/methodology/approach: An extensive literature review using the “Preferred Reporting Items for Systematic Review and Meta-Analysis” method was carried out on the impact of the COVID-19 pandemic on supply chains and Industry 4.0 technologies. The study was undertaken by selecting keywords validated by experts and a search was conducted in the Scopus, ProQuest, and Google Scholar databases. Publications from the leading journals on these topics were selected. The bibliographical search resulted in 1484 articles followed by multiple layers of filtering. Finally, the most pertinent articles were selected for reviewing, and a total of 53 articles were analysed. Findings: This study discusses the impact of COVID-19 on the supply chain and how the emerging technologies of Industry 4.0 can help manufacturers to ease the impact. These technologies will enhance the production system through the automation and optimization of production flow convergence, enabling efficiencies and improvements among the suppliers, manufacturers, and consumers in the COVID-19 situation. Originality/value: The study summarizes the impact of the COVID-19 on supply chains and shows the potential of Industry 4.0 technologies to lessen the impact on manufacturing supply chains. This is valuable information for policymakers and practitioners so that they can get insights and take necessary actions.

Effects of Fences and Green Zones on the Air Flow and PM2.5 Concentration around a School in a Building-Congested District

We investigated the effects of wall- and tree-type fences on the airflow and fine particular matter (PM2.5) concentration around a school using a computational fluid dynamics (CFD) model. First, we validated the simulated wind speeds and PM2.5 concentrations against measured values, and the results satisfied the recommended criteria of the statistical validation indices used. Then, we evaluated the fence effects for 16 inflow directions by conducting numerical simulations with different fence types and heights. With east–southeasterly inflow, relatively high PM2.5 from the road was transported to the school. However, the wall-type fence prevented the PM2.5 from the road from entering the school, and the PM2.5 concentration decreased significantly downwind of the fence. With east–northeasterly inflow, the horizontal wind speed decreased due to the drag caused by the tree-type fence, resulting in a shift in the flow convergence region. The PM2.5 concentration decreased in the region of strengthened upward flow. This occurred because the number of pollutants transported from the background decreased. A comparison of the two fence types revealed that the effect of the tree-type fence on inbound pollutants was more significant, due to increased upward flows, than the effect of the wall-type fence.

An Advanced Proppant Depositional Study with Post-Production Flow Evaluation in a 10' X 20', Transverse Fracture, Slot Flow Configuration

While the shale revolution flourished prior to the pandemic, the increased supply bubble had already taken a toll on the profitability of horizontal wells with multiple transverse fractures. A significant shift previously occurred to reduce proppant costs by utilizing cheaper, smaller grained, lower strength, and broadly diverse grain sized sands. Due to the extremely low matrix permeability in active unconventional plays, the use of regional 40/70 and 100 mesh sands (50/140, 70/140, etc.) has become commonplace with adequate results. What remains is the need for enhanced conductivity near the wellbore to handle the radial flow convergence loss when the well is brought on-line. Research is being conducted to better understand how to efficiently increase near-wellbore conductivity using lead and tail-in stages with higher permeability (ceramic) proppant when frac sand is the majority of the material pumped into the well. A 10’x20’ Large Slot Flow (LSF) apparatus, equipped with multiple injection points, side-panel ports for leak-off and/or post-test injection, with the ability to be disassembled for sample analysis after testing, was utilized for this project. For this data, the inlet was moved to the centerline of the wall to allow for proppant and fluid to transport into an environment similar to a horizontal wellbore connecting with a transverse fracture. Various tests were conducted to study the depositional characteristics of lead and tail-in stages with ceramic proppant (15% BW-Lead, 5% BW-Tail) and a main stage of 100 mesh sand (80%). Three inlet positions were established in the lower, middle, and upper portion of the apparatus. Tests were recorded to visually capture the efficiency of placing the premium proppants near the wellbore for increased conductivity. A key addition to the study was the innovative, post-production analysis through the side-panel ports. Fluid was injected into the proppant pack to observe the effect of increased near-wellbore conductivity. To improve visibility, the fluid was colored with a fluorescent dye and observed under black lights. The injection front geometry was radial initially, but typically elongated toward the exit point after contacting the ceramic proppant. The amount of time and distance for the fluid to travel through the sand pack, as well as that for the fluid to reach the offtake point once the ceramic bed was reached, were monitored and recorded. The ratio of the velocities should represent a valid qualitative indication of the conductivity contrast of the two proppants. This paper will describe the unique experimental configuration, outline the testing program for both deposition and post-production assessments performed on the deposits, along with results that could provide better design practices leading to improved transverse fracture performance.

Late Weichselian ice-sheet flow directions in the Russian northern Barents Sea from high-resolution imagery of submarine glacial landforms

The locations and orientations of more than 1000 late Quaternary subglacial and ice-marginal landforms, including streamlined sedimentary bed forms, glacitectonic hill-hole pairs, meltwater channels, and eskers, were mapped from blocks of multibeam data (area of 4861 km2) in the little-known Russian Barents Sea. Between Sentralbanken and Admiralty Bank, at ~75°N, there is evidence for southward ice flow. Ice-flow indicators between Franz Josef Land and Novaya Zemlya show northeast flow into the head of St. Anna Trough. There is also evidence of southeast flow off the bank to the south of Franz Josef Land, and of flow convergence with northeast-flowing ice in Sedov Trough. Northeast flow of ice between Novaya Zemlya and Franz Josef Land suggests that the latter archipelago was not overrun by ice flowing north from the Barents Sea and, therefore, that a subsidiary ice dome was likely on Franz Josef Land. A major ice divide was also present at ~76°N –77°N in the Russian Barents Sea.