Understanding the interplay of capillary and viscous forces in CO2 core flooding experiments

Interaction between capillary and viscous forces significantly affects the flow instability in immiscible displacement, which is usually investigated by visualization of flow patterns in 2d porous micromodels or in 3d system equipped with X-ray CT. However, in most practical applications, visualization of flow in porous media is not possible and the pressure signal is often as one of the important sources of information. Core flooding experiments were implemented in this study to investigate the interplay of capillary and viscous effects by analysis of differential pressure. Water and crude oil were employed as defending fluid, and different states of CO2 were injected as invading fluid. The inlet was set as the constant injection flow rate while the outlet as the constant pressure. In viscous-dominated displacement, differential pressure evidently depends on the injection rate and the pressure decline curve is fitted by a power function. The exponent of the function is found to be significantly larger at the crossover between capillary-dominated and viscous-dominated regions. In capillary-dominated displacement, the pressure profile is characterized by a pressure jump at the beginning and intermittent fluctuations during the displacement. Further analysis by wavelet decomposition indicates a transition point existing in standard deviation of pressure fluctuations when the displacement is transformed from capillary-dominated to viscous-dominated. The experimental results are finally verified by a macroscopic capillary number, which characterizes the interaction between capillary and viscous forces at a critical value of , agreeing well with the Log Nca-Log M phase diagram

A Multi-Objective Routing Algorithm Based on Auction Game for Space Information Network

This paper aims to create a resource-saving method for the routing problem in space information network. To this end, a multi-objective routing algorithm was created based on game theory for space information network. Specifically, the auction game was introduced to solve the routing problem using the delay-tolerating network (DTN) protocol. Considering the topological periodicity of low earth orbit (LEO) satellite network, a typical space information network, the dynamic topological structure was divided into relatively static time slots. Then, the routing problem was solved through the auction game in these slots. The proposed algorithm can minimize the number of selfish nodes in the network and avoid network congestion resulted from excessive resource consumption of individual nodes. Finally, the proposed algorithm was compared with other well-known routing models like the epidemic routing model (Epidemic) and the first contact routing model (FC). The results show that the proposed algorithm outperformed the contrastive models in both average delay and network overhead ratio. The research findings shed important new light on the routing of space information network

Allocating Limited Resources to Protect a Massive Number of Targets using a Game Theoretic Model

Resource allocation is the process of optimizing the rare resources. In the area of security, how to allocate limited resources to protect a massive number of targets is especially challenging. This paper addresses this resource allocation issue by constructing a game theoretic model. A defender and an attacker are players and the interaction is formulated as a trade-off between protecting targets and consuming resources. The action cost which is a necessary role of consuming resource, is considered in the proposed model. Additionally, a bounded rational behavior model (Quantal Response, QR), which simulates a human attacker of the adversarial nature, is introduced to improve the proposed model. To validate the proposed model, we compare the different utility functions and resource allocation strategies. The comparison results suggest that the proposed resource allocation strategy performs better than others in the perspective of utility and resource effectiveness.Comment: 14 pages, 12 figures, 41 reference

The effect of CO2 phase on drainage process by analysis of transient differential pressure

Authors gratefully acknowledge the financial supports from China Scholarship Council (CSC) and UK India Education & Research Initiative (UKIERI).Peer reviewedPostprin

Black Garlic Improves Heart Function in Patients With Coronary Heart Disease by Improving Circulating Antioxidant Levels

Background: Black garlic (BG) has many health-promoting properties.Objectives: We aimed to explore the clinical effects of BG on chronic heart failure (CHF) in patients with coronary heart disease (CHD).Design: The main components of BG were measured by gas chromatography–mass spectrometry (GC–MS) and its antioxidant properties were determined by the clearance rate of free radicals. One hundred twenty CHF patients caused by CHD were randomly and evenly assigned into BG group and placebo group (CG). The duration of treatment was 6 months. Cardiac function was measured according to the New York Heart Association (NYHA) functional classification system. The following parameters were measured, including walking distance, BNP precursor N-terminal (Nt-proBNP), left-ventricular ejection fraction (LVEF) value, and the scores of quality of life (QOL). The circulating antioxidant levels were compared between two groups.Results: There are 27 main compounds in BG with strong antioxidant properties. BG treatment improved cardiac function when compared with controls (P < 0.05). The QOL scores and LVEF values were higher in the BG group than in the CG group while the concentration of Nt-proBNP was lower in the BG group than in the CG group (P < 0.05). Circulating antioxidant levels were higher in the BG group than in the CG group. Antioxidant levels had positive relation with QOL and LVEF values, and negative relation with Nt-proBNP values.Conclusion: BG improves the QOL, Nt-proBNP, and LVEF in CHF patient with CHD by increasing antioxidant levels

Analysis of the efficacy of Chinese medicine in the treatment of covid-19 and the study of medication pattern

In order to explore the efficacy and medication pattern of Chinese medicine in the treatment of COVID-19, we conducted statistics on the medication use of Chinese medicine based on some clinical data of novel coronavirus pneumonia (COVID-19) and related literature, and used the statistical method of frequency analysis to screen out the drugs with high frequency of use in patients with different types of novel coronavirus pneumonia (COVID-19). We used the statistical method of frequency analysis to screen out the core drugs with high frequency of use in patients with different types of novel coronavirus pneumonia (COVID-19) and the related main drug symptoms; Several drugs with good conversion effect were screened out by mean comparison method in terms of conversion time of drugs, and drug analysis was also conducted by data mining and other methods, so as to derive several groups of core drug combinations of Chinese medicine in the treatment of novel coronavirus pneumonia (COVID-19), and to provide data support and research directions for the effectiveness of Chinese medicine intervention in the treatment of novel coronavirus pneumonia (COVID-19)

preparationofticl4withthetitaniumslagcontainingmagnesiaandcalciainacombinedfluidizedbed

This paper describes a new method for producing TiCl4 by chloridizing materials of high content CaO and MgO, in which a combined fluidized bed is used as a reactor to avoid agglomeration between particles caused by molten CaCl2 and MgCl2. The combined fluidized bed consists of at least a riser tube and a semi-circulating fluidized bed. Two kinds of high titanium slag, in which the total mass content of CaO and MgO is 2.03% and 9.09% respectively, are employed to examine the anti-agglomeration effect and the conversion of the materials when the temperature ranges are between 923.15K and 1073.15K, gas apparent velocity 0.7-1.1m.s(-1), and inlet amount of solid materials is 4.6-7.0kg.h(-1). It is found that the anti-agglomeration effect in the combined fluidized bed is satisfactory and the new method can achieve a TiCl4 production capacity of 14.0-75.4t.m(-2).d(-1) in relation to 25.0-40.0t.m(-2).d(-1) from the conventional bubble bed. Furthermore, low-temperature chloridization, for example, at 923K or 973K, can also be used to produce TiCl4 and avoid agglomeration