An advanced general dominant eigenvalue method of accelerating successive substitution during flash calculation for compositional reservoir model

The efficiency and accuracy of phase equilibrium calculations are essential in compositional reservoir models. Usually, a significant part of the computational effort in compositional reservoir simulations is spent on phase equilibrium calculations. The nonlinear nature of phase equilibrium calculations requires an iterative solution procedure. Although the successive substitution method (SSM) is robust and simple to implement, it suffers from slow convergence, especially near the critical point of the mixture. The general dominant eigenvalue method (GDEM) has been widely used to accelerate SSM, but its stability and efficiency deteriorate as the temperature and pressure approach the critical point. This paper proposes a modified form of GDEM to improve its performance in the near-critical region. The modifications have two aspects. First, the liquid phase fraction in the mixture is added as a variable when performing GDEM acceleration, improving both stability and efficiency. The second modification is a post-calibration step imposed to replace the conventional criterion, which is applied before triggering GDEM. With the help of the post-calibration step, the stability of the modified GDEM is ensured, and more importantly, the calculation efficiency can be improved. Numerical tests of three hydrocarbon mixtures, including different numbers of components, show that the stability of the modified GDEM is almost the same as SSM and that its calculation efficiency is much higher than SSM and the conventional GDEM.Cited as: Wang, X., Wei, D., Wang, X., Zhao, X., Li, J., Noetinger, B. An advanced general dominant eigenvalue method of accelerating successive substitution during flash calculation for compositional reservoir model. Advances in Geo-Energy Research, 2022, 6(3): 241-251. https://doi.org/10.46690/ager.2022.03.0

Novel research methods on the net-zero economy of climate finance in the energy sector

This is a perspective, about the future climate policy of Pakistan, to improve the harvest of Green Climate Funds (GCF). This paper takes upon the calculation of climate financing potential in the context of the energy sector of Pakistan by estimating the potential of becoming a net-zero sector in Pakistan’s Economy. The study has identified several options for the government to reallocate the energy mix and tie the energy demand targets with climate targets for a green future of Pakistan. The study has used basic excel tools to calculate facts from the available data sets in Pakistan. The study found that, if Pakistan chooses to shift from dirty sources of energy production to the use of cleaner inputs for energy production, Pakistan can generate a significant amount of climate finance by reducing the emissions from energy production, which are recordable, traceable, and can be evaluated by any of the third-party evaluating organization. The initial cost for Pakistan will cause some discrepancies in some of the macroeconomic indicators and may also cause budget imbalances it will surely help the economy to achieve the targets of becoming a net-zero economy and be able to harvest Green Climate Funds in long term with much faster rate, which can overpass the investments made or being made in this sector and will create a significant amount jobs in the economy, which will be green jobs, promoting environmental friendly output and sustainable growth

Cosmic test of sTGC detector prototype made in China for ATLAS experiment upgrade

Following the Higgs particle discovery, the Large Hadron Collider complex will be upgraded in several phases allowing the luminosity to increase to $7 \times 10^{34}cm^{-2}s^{-1}$. In order to adapt the ATLAS detector to the higher luminosity environment after the upgrade, part of the ATLAS muon end-cap system, the Small Wheel, will be replaced by the New Small Wheel. The New Small Wheel includes two kinds of detectors: small-strip Thin Gap Chambers and Micromegas. Shandong University, part of the ATLAS collaboration, participates in the construction of the ATLAS New Small Wheel by developing, producing and testing the performance of part of the small-strip Thin Gap Chambers. This paper describes the construction and cosmic-ray testing of small-strip Thin Gap Chambers in Shandong University

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Experimental Study and Numerical Simulation of Dynamic Stress-Strain of Directional Blasting with Water Jet Assistance

Effective control of the explosive energy and the propagation direction of blast-induced crack and minimizing damage of remaining rock mass are the main purposes of directional-controlled blasting. In this paper, the experimental test on blast strain fields affected by water jet slot and blasthole wall protection material is conducted. Next, the FEM software ANSYS/LSDYNA is used to simulate the blast‐induced crack propagation and the blast stress wave transmission of different types of blasthole, and the distribution and evolution law of dynamic blast stress are also analyzed. The results indicate that the existence of blasthole wall protection material is not only beneficial to the “guiding effect” of blast‐induced crack propagation of water jet slot but also beneficial to reduce blast-induced damage of remaining rock mass. Besides, the bigger Dm/rb is, the weaker the “guiding effect” and “blasthole wall protection effect” by water jet slot and wall protection material are