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Chemical-assisted MMP reduction on methane-oil systems:Implications for natural gas injection to enhanced oil recovery

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Petroleum 2024年第1期10卷 101-108页

作者： Mohamed Almobarak Matthew b.Myers colin D.Wood Yongbing Liu Ali Saeedi Quan Xie Discipline of Petroleum Engineering WA School of Mines: Minerals Energy and Chemical Engineering Curtin University Commonwealth Scientific and Industrial Research Organization Curtin University Oil and Gas Innovation Centre Management State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation

Miscible natural gas injection is widely considered as a practical and efficient enhanced oil recovery technique. However, the main challenge in this process is the high minimum miscibility pressure（MMP）between natural gas and crude oil, which limits its application and recovery factor, especially in hightemperature reservoirs. Therefore, we present a novel investigation to quantify the effect of chemicalassisted MMP reduction on the oil recovery factor. Firstly, we measured the interfacial tension（IFT） of the methane-oil system in the presence of chemical or CO2to calculate the MMP reduction at a constant temperature（373K） using the vanishing interfacial tension（VIT） method. Afterwards, we performed three coreflooding experiments to quantify the effect of MMP reduction on the oil recovery factor under different injection *** interfacial tension measurements show that adding a small fraction（1.5 wt%） of the tested surfactant（SOLOTERRA ME-6） achieved 9% of MMP reduction, while adding 20 wt% of CO2to the methane yields 13% of MMP reduction. Then, the coreflooding results highlight the significance of achieving miscibility during gas injection, as the ultimate recovery factor increased from 65.5% under immiscible conditions to 77.2% using chemical-assisted methane, and to 79% using gas mixture after achieving near miscible condition. The results demonstrate the promising potential of the MMP reduction to significantly increase the oil recovery factor during gas injection. Furthermore, these results will likely expand the application envelop of the miscible gas injection, in addition to the environmental benefits of utilizing the produced gas by re-injection/recycling instead of flaring which contributes to reducing the greenhouse gas emissions.

关键词： Gas injection Enhanced oil recovery Miscibility Coreflooding

Quasi-static simulations of compact polydisperse particle systems

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Particuology 2010年第2期8卷 119-126页

作者： colin Thornton School of Civil Engineering University of Birmingham Birmingham UK

The Discrete Element Method （DEM） was originally devised by Cundail and Strack （1979）, as a technique to examine the micromechanics of granular media with the anticipation that this would lead to more physically reliable continuum theories to describe the quasi-static deformation of granular material such as sand. However, the methodology models the evolution of a system of particles as a dynamic process. Consequently there have been numerous publications of the application of DEM to an increasingly wider variety of problems in many areas of engineering and science. This paper, however, focuses on the orig- inal motivation for DEM and attempts to provide a state-of-the-art understanding of the quasi-static deformation of granular media. 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier b.V. All rights reserved.

关键词： Discrete Element MethodQuasi-static deformationGranular media

Eventual Positivity of Hermitian Polynomials and Integral Operators

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Chinese Annals of Mathematics,Series b 2016年第1期37卷 83-94页

作者： colin TAN Department of Mathematics National University of Singapore Block S17 10 Lower Kent Ridge Road Singapore 119076.

Quillen proved that if a Hermitian bihomogeneous polynomial is strictly positive on the unit sphere, then repeated multiplication of the standard sesquilinear form to this polynomial eventually results in a sum of Hermitian squares. Catlin-D'Angelo and Varolin deduced this positivstellensatz of Quillen from the eventual positive-definiteness of an associated integral operator. Their arguments involve asymptotic expansions of the bergman kernel. The goal of this article is to give an elementary proof of the positive-definiteness of this integral operator.

关键词： Asymptotics Polynomial Positivity

T-DNA-Induced Chromosomal Translocations in feronia and anxur2 Mutants Reveal Implications for the Mechanism of Collapsed Pollen Due to Chromosomal Rearrangements

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Molecular Plant 2014年第10期7卷 1591-1594页

作者： colin Ruprecht[a],, Andrew Carroll[b] Staffan Persson[a],[c], a Max-Planck-Institute for Molecular Plant Physiology Am Muehlenberg 1 14476 Potsdam Germanyb Department of Biology Stanford University Stanford CA 94305 USAc ARC Centre of Excellence in Plant Cell Walls School of Botany University of Melbourne Parkville 3010 Victoria Australia

Dear Editor, Approximately every fifth Arabidopsis T-DNA inser- tion line contains chromosomal translocations caused by the inserted T-DNA （Clark and Krysan, 2010）. Albeit broad use of T-DNA lines for mutant analysis, little is known about the consequences of these chromosomal rearrangements and only a few studies describe chromosomal aberrations in the mutant lines. While plant growth in general is not affected by such chromosomal translocations, defects in gametophyte development have been observed in lines that are heterozygous for the T-DNA insertion （Ray et al., 1997; Curtis et al., 2009）.

关键词： T-DNA插入染色体易位染色体重排突变系体显示苹果属机制花粉

Eventual Positivity of Hermitian Algebraic Functions and Associated Integral Operators

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Chinese Annals of Mathematics,Series b 2020年第6期41卷 967-988页

作者： colin TAN Wing-Keung TO Department of Statistics&Applied Probability National University of Singapore Current address:Science Mat hematics and TechnologySingapore University of Technology and Design8 Somapah RoadSingapore 487372 Department of Mathematics National University of SingaporeBlock S1710 Lower Kent Ridge RoadSingapore 119076

Quillen proved that repeated multiplication of the standard sesquilinear form to a positive Hermitian bihomogeneous polynomial eventually results in a sum of Hermitian squares,which was the first Hermitian analogue of Hilbert s seventeenth problem in the nondegenerate *** Catlin-D’Angelo generalized this positivstellensatz of Quillen to the case of Hermitian algebraic functions on holomorphic line bundles over compact complex manifolds by proving the eventual positivity of an associated integral *** arguments of Catlin-D’Angelo involve subtle asymptotic estimates of the bergman *** this article,the authors give an elementary and geometric proof of the eventual positivity of this integral operator,thereby yielding another proof of the corresponding positivstellensatz.

关键词： Hermitian algebraic functions Integral operators Positivity

Homological behavior of idempotent subalgebras and Ext algebras

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Science China Mathematics 2020年第2期63卷 309-320页

作者： colin Ingalls Charles Paquette School of Mathematics and Statistics Carleton UniversityOttawaON K1S 5E6Canada Department of Mathematics and Computer Science Royal Military College of CanadaKingstonON K7K 7B4Canada

Let A be a(left and right) Noetherian ring that is semiperfect. Let e be an idempotent of A and consider the ring Γ :=(1-e)A(1-e) and the semi-simple right A-module Se := e A/e rad A. In this paper, we investigate the relationship between the global dimensions of A and Γ, by using the homological properties of Se. More precisely, we consider the Yoneda ring Y(e) := Ext_A~*(Se, Se) of e. We prove that if Y(e) is Artinian of finite global dimension, then A has finite global dimension if and only if so does Γ. We also investigate the situation where both A and Γ have finite global dimension. When A is Koszul and finite dimensional, this implies that Y(e) has finite global dimension. We end the paper with a reduction technique to compute the Cartan determinant of Artin algebras. We prove that if Y(e) has finite global dimension, then the Cartan determinants of A and Γ coincide. This provides a new way to approach the long-standing Cartan determinant conjecture.

关键词： global dimension Noetherian ring semiperfect ring idempotent subalgebra Cartan determinant

Efficient and Stereoselective Synthesis of C-(β-2'-Deoxynucleosides)

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有机化学 2004年第Z1期24卷 27-28页

作者： WU,Qin-Pei REES,b.colin School of Life Science Beijing Institute of Technology Beijing 100081 King''s College London WC2R 2LS UK

　　The formation of triplex DNA is, in principle, an effective way of regulating the expression of selected genes.[1]Many cytosine mimics were investigated to form triplex DNA, e.g., 2-amino-(2'-deoxy-β-D-ribofuranosyl)pyridine (9)was proved to have some effectiveness in stabilizing triplex DNA under neutral conditions.[2] Stereoselective synthesis of 9 was achieved starting from 2-deoxyribose.……

关键词： triplex DNA

Corticospinal activity during a single-leg stance in people with chronic ankle instability

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Journal of Sport and Health Science 2022年第1期11卷 58-66页

作者： Masafumi Terada Kyle b.Kosik Ryan S.McCann colin Drinkard Phillip A.Gribble College of Sport and Health Science Ritsumeikan UniversityKusatsuShiga 525-8577Japan Department of Athletic Training&Clinical Nutrition University of KentuckyLexingtonKY 40536-0200USA School of Rehabilitation Sciences Old Dominion UniversityNorfolkVA 23529USA Westlake High School Athletics AustinTX 78746USA

Purpose:The aim of the study was to determine whether corticospinal excitability and inhibition of the tibialis anterior during single-leg standing differs among individuals with chronic ankle instability(CAI),lateral ankle sprain copers,and healthy ***:Twenty-three participants with CAI,23 lateral ankle sprain copers,and 24 healthy control participants *** motor threshold(AMT),normalized motor-evoked potential(MEP),and cortical silent period(CSP)were evaluated by transcranial magnetic stimulation while participants performed a single-leg standing ***:Participants with CAI had significantly longer CSP at 100%of AMT and lower normalized MEP at 120%of AMT compared to lateral ankle sprain copers(CSP100%:p=0.003;MEP120%:p=0.044)and controls(CSP100%:p=0.041;MEP120%:p=0.006).Conclusion:This investigation demonstrate altered corticospinal excitability and inhibition of the tibialis anterior during single-leg standing in participants with *** research is needed to examine the effects of corticospinal maladaptations to motor control of the tibial anterior on postural control performance in those with CAI.

关键词： Ankle sprain Joint instability Motor cortex Postural control

A Comparative Analysis of Four Kinds of Polysaccharides Purified from Furcellaria lumbricalis

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Journal of Ocean University of China 2007年第1期6卷 16-20页

作者： bARROW colin Ocean Nutrition Canada Ltd. Dartmouth Nova Scotia B2Y 4T6 Canada

Four kinds of polysaccharides (FA, Fb, FC and FD) were extracted and purified from a red alga Furcellaria lumbri-calis. Their monosaccharide composition, average molecular mass (Mw) and structural feature were determined by gas chromatog-raphy (GC), high performance gel permeation chromatography (HPGPC) and Fourier transform infrared spectroscopy (FTIR), respectively. The results showed that FA and Fb were composed of galactose (Gal), 3,6-anhydro-galactose (AnG) and 4-sulfated-galactose (G4S), which were structurally similar to β-carrageenan and κ-carrageenan. FC was composed of sulfated galactose and small amount of AnG, indicating that it was a hybrid-sulfated galactan. FD was composed of α-1, 4-glucose and belonged to floridean starch. The respective yields of FA, Fb, FC and FD were 4.84%,33.74%,8.76% and 13.5%, and the cor-responding Mw were 537 kD, 432 kD, 513 kD and 51 kD respectively. Owning to its high content ( >60%) of polysaccharide, F. lumbricalis will be a good source of marine sulfated polysaccharide and shows its potential utilization in food and medicine.

关键词： Furcellaria lumbricalis sulfated galactan carrageenan floridean starch