Shear rheology is a fundamental property of soft matter,which can be deformed.Although the shear rheology of fluids has been well studied at the macroscopic scale,understanding the microscopic processes of rheology at...Shear rheology is a fundamental property of soft matter,which can be deformed.Although the shear rheology of fluids has been well studied at the macroscopic scale,understanding the microscopic processes of rheology at the single-particle level remains a challenging issue.Dusty plasma serves as an ideal platform for exploring microscopic dynamics of system at the individual particle level.Here,we study the shear rheology of confined double rings of strongly coupled dust particles in a dusty plasma.The outer ring is actively driven to rotate using laser illumination.Depending on the particle number,the inner ring may passively rotate following the outer ring at different angular speeds,resulting in shear rheology.The number of dust particles influences particle arrangement,which is characterized by the pair correlation function,bond-orientational order parameter,and triangle skewness.That further alters structural stability,significantly affecting the shear rheology.展开更多
As the base oil of the current flat-rheology synthetic drilling fluid is high in cost and not renewable, the biodiesel-based flat-rheology drilling fluid with low-cost, environmental protection and renewable advantage...As the base oil of the current flat-rheology synthetic drilling fluid is high in cost and not renewable, the biodiesel-based flat-rheology drilling fluid with low-cost, environmental protection and renewable advantage was studied. Based on the optimization of raw materials, a cheap, environment-friendly biodiesel of soybean oil ethyl ester with good fluidity at low temperature was selected as the base oil. By selecting high oil-water ratio and introducing cationic surfactant into the auxiliary emulsifier, the thickening of biodiesel-based emulsion caused by hydrolysis and saponification after high-temperature aging was effectively eliminated. The organoclay prepared with cationic modifier of hexadecyl trimethyl ammonium chloride was used to improve the rheologic properties, stability and fluid loss of the drilling fluid while preventing low-temperature thickening. A flat-rheology modifier was synthesized with dimer fatty acid and cocoanut fatty acid diethanolamide, which could form strong network structure in the biodiesel-based drilling fluid to adjust effectively rheological properties of the drilling fluid. A biodiesel-based flat-rheology drilling fluid system with the density of 1.2 g/cm^(3) has been formulated which has constant rheology in the temperature range of 2-90 ℃, temperature tolerance of 160 ℃, seawater salinity tolerance of 5%, shale cuttings tolerance of 10%, and is environmentally friendly.展开更多
Flow assurance is one of the core issues in safe and economical operation of waxy crude pipelines.Its essence lies in flow and heat transfer of the crude.In the past 10 years,the authors＇ team has achieved a lot of i...Flow assurance is one of the core issues in safe and economical operation of waxy crude pipelines.Its essence lies in flow and heat transfer of the crude.In the past 10 years,the authors＇ team has achieved a lot of innovative results in aspects of waxy crude rheology,flow assurance assessment,and pipelining technologies on the basis of decades of studies.The rheological characteristics of waxy crude are much better understood,and a method for quantitatively simulating the effect of flow shear was developed based on some theoretical breakthroughs.Studies of the mechanism of waxy crude rheology have been deepened to the quantitative level.After successful development of efficient numericalalgorithms,accurate simulations have been achieved for various complex flow and heat transfer situations in waxy crude pipelining,and a reliability-based approach to flow assurance assessment has been set up.New pipelining technologies have been developed such as batching pour-point depressant-（PPD-） treated multiple-waxy-crudes,intermittent transport of waxy crudes through long-distance pipelines,and batching hot and cold crudes.By their application,a series of problems hindering safe,efficient and flexible operation of waxy crude pipelines were tackled,demonstrating that transportation technologies for waxy crude have advanced to a new and high level.展开更多
Structure of emulsifiers or functionality and molecular weight determines its rheology, emulsification and stability of emulsion explosives. Rheology of typical emulsifiers was studied by automatic rheometer. Relation...Structure of emulsifiers or functionality and molecular weight determines its rheology, emulsification and stability of emulsion explosives. Rheology of typical emulsifiers was studied by automatic rheometer. Relations between rheology and structural properties of typical emulsifiers were analyzed. Experimental results show that viscosity of emulsifiers didn＇ t change with shear rate at room temperature and appeared properties of Newtonian fluid. Viscosity of different component emulsifiers declines with temperature in different modes. The change of strain doesn＇ t affect modu- lus of emulsifiers. Loss modulus increases linearly with the increase of frequency in oscillation and storage modulus does non-linearly. The higher the temperature is, the lower change amplitude of loss modulus with frequency will be. The emulsifiers with imide and amide functionality for emulsion explosives have better shear properties at high temperature and better shapingness and stability at room temperature than other emulsifiers with ester and Sorbin Monoleate （SMO） functionality.展开更多
Numerical modeling of salt tectonics is a rapidly evolving field; however, the constitutive equations to model long-term rock salt rheology in nature still remain controversial. Firstly, we built a database about the ...Numerical modeling of salt tectonics is a rapidly evolving field; however, the constitutive equations to model long-term rock salt rheology in nature still remain controversial. Firstly, we built a database about the strain rate versus the differential stress through collecting the data from salt creep experiments at a range of temperatures（20–200 ℃） in laboratories. The aim is to collect data about salt deformation in nature, and the flow properties can be extracted from the data in laboratory experiments.Moreover, as an important preparation for salt tectonics modeling, a numerical model based on creep experiments of rock salt was developed in order to verify the specific model using the Abaqus package. Finally, under the condition of low differential stresses, the deformation mechanism would be extrapolated and discussed according to microstructure research. Since the studies of salt deformation in nature are the reliable extrapolation of laboratory data, we simplified the rock salt rheology to dislocation creep corresponding to power law creep（n = 5） with the appropriate material parameters in the salt tectonic modeling.展开更多
Polymer injectivity is an important factor for evaluating the project economics of chemical flood,which is highly related to the polymer viscosity.Because the flow rate varies rapidly near injectors and significantly ...Polymer injectivity is an important factor for evaluating the project economics of chemical flood,which is highly related to the polymer viscosity.Because the flow rate varies rapidly near injectors and significantly changes the polymer viscosity due to the non-Newtonian rheological behavior,the polymer viscosity near the wellbore is difficult to estimate accurately with the practical gridblock size in reservoir simulation.To reduce the impact of polymer rheology upon chemical EOR simulations,we used an efficient multilevel local grid refinement（LGR）method that provides a higher resolution of the flows in the near-wellbore region.An efficient numerical scheme was proposed to accurately solve the pressure equation and concentration equations on the multilevel grid for both homogeneous and heterogeneous reservoir cases.The block list and connections of the multilevel grid are generated via an efficient and extensible algorithm.Field case simulation results indicate that the proposed LGR is consistent with the analytical injectivity model and achieves the closest results to the full grid refinement,which considerably improves the accuracy of solutions compared with the original grid.In addition,the method was validated by comparing it with the LGR module of CMG_STARS.Besides polymer injectivity calculations,the LGR method is applicable for other problems in need of near-wellbore treatment,such as fractures near wells.展开更多
The present study investigates the effects of incorporating oat bran(OB) into Chinese steamed bread(CSB). Different levels(5%, 10% and 15%) of OB were used to replace wheat flour in the manufacture of CSB. The rheolog...The present study investigates the effects of incorporating oat bran(OB) into Chinese steamed bread(CSB). Different levels(5%, 10% and 15%) of OB were used to replace wheat flour in the manufacture of CSB. The rheological properties of the dough were measured(water absorption(WA), development time, mixing tolerance, extensibility and stickiness). The addition of OB significantly increased WA, development time and stickiness, whereas decreased extensibility of dough. The physical properties of CSB were determined using specific volume, loaf height, moisture, and texture analysis. The nutritional quality of the bread was also analysed using an in vitro digestion method mimicking intestinal digestion. The results illustrated that the incorporation of OB into wheat flour decreases specific volume and softness of CSB. The addition of OB decreased the glycaemic response of steamed bread.This study illustrates the potential addition of OB to improve the nutritional quality of CSB.展开更多
The microstructures on electrode level are crucial for battery performance, but the ambiguous understanding of both electrode microstructures and their structuring process causes critical challenges in controlling and...The microstructures on electrode level are crucial for battery performance, but the ambiguous understanding of both electrode microstructures and their structuring process causes critical challenges in controlling and evaluating the electrode quality during fabrication. In this review, analogous to the cell microenvironment well-known in biology, we introduce the concept of ‘‘active material microenvironment”(ME@AM)that is built by the ion/electron transport structures surrounding the AMs, for better understanding the significance of the electrode microstructures. Further, the scientific significance of electrode processing for electrode quality control is highlighted by its strong links to the structuring and quality control of ME@AM. Meanwhile, the roles of electrode rheology in both electrode structuring and structural characterizations involved in the entire electrode manufacturing process(i.e., slurry preparation, coating/printing/extrusion, drying and calendering) are specifically detailed. The advantages of electrode rheology testing on in-situ characterizations of the electrode qualities/structures are emphasized. This review provides a glimpse of the electrode rheology engaged in electrode manufacturing process and new insights into the understanding and effective regulation of electrode microstructures for future high-performance batteries.展开更多
The melt rheological behaviors of the PET/E-HDP(for short of Easily Hydrolyzed and Easily Dyed Polyester) blending systems at different blending ratios were investigated by the capillary rheometer. The E-HDP is derive...The melt rheological behaviors of the PET/E-HDP(for short of Easily Hydrolyzed and Easily Dyed Polyester) blending systems at different blending ratios were investigated by the capillary rheometer. The E-HDP is derived from polyethylene terephathalate (PET) modified through copolycondensation with sulfonate moiety, (sodiosulfo) isophthalate (Na-SIP) and iso-phthalic acid(IPA). The results showed that the apparent viscosity and non-Newtonian index of the PET/E-HDP blend system had the non-linearity change with the change of the blend ratio of PET/E-HDP. The anomaly of the viscous flow activation energy change was founded as the mass fraction of E-HDP was about 40% in the blend system,suggesting the presence of reversible crosslinked structure formed by strong polar tangling points and the phase separation owing to poor compatibility between the PET and展开更多
Helical hierarchy found in biomolecules like cellulose,chitin,and collagen underpins the remarkable mechanical strength and vibrant colors observed in living organisms.This study advances the integration of helical/ch...Helical hierarchy found in biomolecules like cellulose,chitin,and collagen underpins the remarkable mechanical strength and vibrant colors observed in living organisms.This study advances the integration of helical/chiral assembly and 3D printing technology,providing precise spatial control over chiral nano/microstructures of rod-shaped colloidal nanoparticles in intricate geometries.We designed reactive chiral inks based on cellulose nanocrystal(CNC)suspensions and acrylamide monomers,enabling the chiral assembly at nano/microscale,beyond the resolution seen in printed materials.We employed a range of complementary techniques including Orthogonal Superposition rheometry and in situ rheo-optic measurements under steady shear rate conditions.These techniques help us to understand the nature of the nonlinear flow behavior of the chiral inks,and directly probe the flow-induced microstructural dynamics and phase transitions at constant shear rates,as well as their post-flow relaxation.Furthermore,we analyzed the photo-curing process to identify key parameters affecting gelation kinetics and structural integrity of the printed object within the supporting bath.These insights into the interplay between the chiral inks self-assembly dynamics,3D printing flow kinematics and photopolymerization kinetics provide a roadmap to direct the out-of-equilibrium arrangement of CNC particles in the 3D printed filaments,ranging from uniform nematic to 3D concentric chiral structures with controlled pitch length,as well as random orientation of chiral domains.Our biomimetic approach can pave the way for the creation of materials with superior mechanical properties or programable photonic responses that arise from 3D nano/microstructure and can be translated into larger scale 3D printed designs.展开更多
Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental concerns.Here,we report a microfluid displacement technology containing a bio-based eco-f...Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental concerns.Here,we report a microfluid displacement technology containing a bio-based eco-friendly material,i.e.,calcium alginate(CaAlg)microspheres for EOR.Two dominant mechanisms responsible for EOR over Ca Alg fluid have been verified,including the microscopic oil displacement efficacy augmented by regulating capillary force(determined by the joint action of interfacial tension and wettability between different phases)and macroscopic sweep volume increment through profile control and mobility ratio reduction.This comprehensive effectiveness can be further impacted when the CaAlg microsphere is embellished ulteriorly by using appropriate amount of sodium dodecyl sulfonate(SDS).The core flooding and nuclear magnetic resonance(NMR)tests demonstrate that CaAlg-SDS microsphere can balance the interphase property regulation(wettability alteration and IFT reduction)and rheology properties,enabling simultaneous profile control and oil displacement.Excessive introduction of SDS will have a negative impact on rheological properties,which is not favored for EOR.Our results show that the involvement of 4-m M SDS will provide the best behavior,with an EOR rate of 34.38%.This cost-effective and environmentally-friendly bio-microspherebased microfluidic displacement technology is expected to achieve“green”oil recovery in future oilfield exploitation.展开更多
Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shapi...Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shaping of carbon aerogels with tailored micro-nano structural textures and geometric features.Herein,a facile extrusion 3D printing strategy has been proposed for fabricating CNT-assembled carbon(CNT/C)aerogel nanocomposites through the extrusion printing of pseudoplastic carbomer-based inks,in which the stable dispersion of CNT nanofibers has been achieved relying on the high viscosity of carbomer microgels.After extrusion printing,the chemical solidification through polymerizing RF sols enables 3D-printed aerogel nanocomposites to display high shape fidelity in macroscopic geometries.Benefiting from the micro-nano scale assembly of CNT nanofiber networks and carbon nanoparticle networks in composite phases,3D-printed CNT/C aerogels exhibit enhanced mechanical strength(fracture strength,0.79 MPa)and typical porous structure characteristics,including low density(0.220 g cm^(-3)),high surface area(298.4 m^(2)g^(-1)),and concentrated pore diameter distribution(~32.8nm).More importantly,CNT nanofibers provide an efficient electron transport pathway,imparting 3D-printed CNT/C aerogel composites with a high electrical conductivity of 1.49 S cm^(-1).Our work would offer feasible guidelines for the design and fabrication of shape-dominated functional materials by additive manufacturing.展开更多
The general development of Rheo-NMR during the last four decades as well as selective hyphenated apparatuses is presented.Based on different magnet types,the current review is divided into two categories,namely low-fi...The general development of Rheo-NMR during the last four decades as well as selective hyphenated apparatuses is presented.Based on different magnet types,the current review is divided into two categories,namely low-field and high-field NMR,while the timedomain NMR is normally applied in the former case and the frequency-domain NMR is adopted in the latter one.Depending on different rheometer cells,it can be further divided into tensile and shear mode Rheo-NMR.The combination of various rheometer cells and NMR facility guarantees our acquisition of molecular level structure and dynamics information under flow conditions,which is crucial for our understanding of the molecular origin of complex fluids.A personal perspective is also presented at last to highlight possible development in this direction.展开更多
Objective:To evaluate the effect of Shen Rou Yang Zhen Decoction on blood rheology of the patients with Piyinxu. Methods:30 cases of patients with Piyinxu were treated with Shen Rou Yang Zhen Decoction.The blood rheol...Objective:To evaluate the effect of Shen Rou Yang Zhen Decoction on blood rheology of the patients with Piyinxu. Methods:30 cases of patients with Piyinxu were treated with Shen Rou Yang Zhen Decoction.The blood rheology was detected before and after treatment. Results:30 cases of patients with Piyinxu were treated for one course of treatment resulting in obvious efficiency in 9 cases(30 % ), efficiency in 19 cases(63.33 % ), inefficiency in 2 cases (6.67%). The overall effective rate was 93.33%. The indexes of blood rheology including blood viscosity and plasma viscosity were significantly reduced (P ＜ 0.01). Conclusions: Shen Rou Yang Zhen Decoction can reduce the blood viscosity and improve the blood rheology in patients with Piyinxu.展开更多
The pumping ability and placement performance of fresh cemented paste backfill(CPB) in underground mined cavities depend on its rheological properties. Hence, it is crucial to understand the rheology of fresh CPB slur...The pumping ability and placement performance of fresh cemented paste backfill(CPB) in underground mined cavities depend on its rheological properties. Hence, it is crucial to understand the rheology of fresh CPB slurry, which is related to CPB mixture design and the temperature underground. This paper presented an experimental study investigating the effects of binder type, content, water chemical properties and content, and temperature, on the rheological properties of CPB material prepared using the tailings of a copper mine in South Australia. Portland cement(PC), a newly released commercially manufactured cement called Minecem(MC) and fly ash(FA) were used as the binders added to the mine tailing materials. Various amounts of two different water types were added to the mixtures in the preparation of backfill material slurry. Six different temperatures ranging from 5 to 60 °C were to investigate the effect of temperature on CPB rheology. Overall, the increasing water content and decreasing temperature lead to lower yield stress. Based on the results obtained from the rheological properties of CPB slurry, it was found that at room temperature(25 °C), with regards to the unconfined compressive strength(UCS) performance, the replacement of 4% PC mixed CPB(28 days UCS 425 k Pa) to 3% MC mixed CPB(28 days UCS 519 k Pa), reduced the slurry yield stress from 210.7 to 178.5 Pa. The results also showed that the chemical composition of water affects the yield stress of CPB slurry and that MC mitigates the negative effect of mine-processed water(MW) and thus lead to improve the rheological properties of the slurry. However, the results suggested that the rheological properties of a mixture using MC is very sensitive to the water volume and temperature change. Therefore, using MC in backfill requires better quality control in slump mixing.展开更多
An oil-based drilling fluid should be stable and tolerant to high temperatures for use in deep drilling. An invert emulsion of water in oil is a good choice as an oil- based drilling fluid which is a mixture of a soli...An oil-based drilling fluid should be stable and tolerant to high temperatures for use in deep drilling. An invert emulsion of water in oil is a good choice as an oil- based drilling fluid which is a mixture of a solid phase and two immiscible liquid phases stabilized by a polymeric surfactant. In deep drilling, due to high temperatures, the polymeric surfactant degrades and a phase separation occurs. Here, octadecyltrimethoxysilane-modified silica nanoparticles were used to form a stable invert emulsion of water in oil for the drilling fluid model which resulted in a milky fluid with the formation of 60 gm water droplets. In addition, rheological study showed that using hydrophobic silica nanoparticles resulted in a stable water in oil invert emulsion with desired properties for a drilling fluid that can be modified by adjusting the nanoparticle nature and content. Aging experiments at 120 ℃ indicated that they also have good stability at high temperatures for challenging drilling operations.展开更多
Excellent drilling fluid techniques are one of the significant guaranteed measures to insure safety, qual- ity, efficiency, and speediness of drilling operations. Dril- ling fluids are generally discarded after the co...Excellent drilling fluid techniques are one of the significant guaranteed measures to insure safety, qual- ity, efficiency, and speediness of drilling operations. Dril- ling fluids are generally discarded after the completion of drilling operations and become waste, which can have a large negative impact on the environment. Drilling mate- rials and additives together with drill cuttings, oil, and water constitute waste drilling fluids, which ultimately are dumped onto soil, surface water, groundwater, and air. Environmental pollution is found to be a serious threat while drilling complex wells or high-temperature deep wells as these types of wells involve the use of oil-based drilling fluid systems and high-performance water-based drilling fluid systems. The preservation of the environment on a global level is now important as various organizations have set up initiatives to drive the usage of toxic chemicals as drilling fluid additives. This paper presents an approach where grass is introduced as a sustainable drilling fluid additive with no environmental problems. Simple water- based drilling fluids were formulated using bentonite, powdered grass, and water to analyze the rheological and filtration characteristics of the new drilling fluid. A particle size distribution test was conducted to determine the par- ticle size of the grass sample by the sieve analysis method. Experiments were conducted on grass samples of 300, 90, and 35 μm to study the characteristics and behavior of the newly developed drilling fluid at room temperature. The results show that grass samples with varying particle sizes and concentrations may improve the viscosity, gel strength, and filtration of the bentonite drilling fluid. These obser- vations recommend the use of grass as a rheological modifier, filtration control agent, and pH control agent to substitute toxic materials from drilling fluids.展开更多
A temperature-resistant, salt-tolerant polyacrylamide, hydrophobically associating polymer （HAP）, was synthesized in the State Key Laboratory of Heavy Oil Processing. The rheological behavior of HAP solution was inv...A temperature-resistant, salt-tolerant polyacrylamide, hydrophobically associating polymer （HAP）, was synthesized in the State Key Laboratory of Heavy Oil Processing. The rheological behavior of HAP solution was investigated by means of flow experiments in porous media and by using a HAAKE RS600 rheometer. The results of Nuclepore membrane filtration showed that filtration time increased sharply when the critical association concentration was reached. Shear rate had a greater impact on viscosity and shear stress with increasing HAP concentration. The HAP solution with a concentration of 100 mg/L （salinity 32,868 mg/L） exhibited negative thixotropy. However, at the same salinity the HAP solution showed thixotropy and its viscosity became greater when the polymer concentration increased to 1,500 mg/L. The flow experiments in cemented core samples indicated that the resistance factor and residual resistance factor of the HAP solution were 31.8 and 12 when polymer concentration and salinity were 1,500 mg/L, 32,868 mg/L at 85℃ respectively, which is favorable for flooding application. Such factors of partially hydrolyzed polyaerylamide 3530S were merely 3.14 and 1.71, so it could not be applied to polymer flooding in the oilfield with high temperature and high salinity.展开更多
The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this...The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.展开更多
Colloidal gas aphrons (CGAs) were first reported by Sebba (1971) as micro bubbles (25-125 μm), composed of a gas nucleus surrounded by a thin surfactant film and created by intense stirring of a surfactant solution. ...Colloidal gas aphrons (CGAs) were first reported by Sebba (1971) as micro bubbles (25-125 μm), composed of a gas nucleus surrounded by a thin surfactant film and created by intense stirring of a surfactant solution. Since then, these colloidal dispersions have been used for diverse applications, with a particular focus on separation processes. However, exploitation of CGAs in petroleum industry is only at the outset. CGAs were first used in west Texas in 1998, under the name Aphron drilling fluids. This kind of fluid is characterized as having a continuous phase, a high viscosity at a low shear rate and containing, as an internal phase, micro air or gas bubbles, non-coalescing and recirculating. In this paper, we illuminate the physical and chemical properties of aphron drilling fluid and its processing mechanism.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275064 and 12475203)the Natural Science Foundation of Hebei Province,China(Grant No.A2024201020)+2 种基金the Regional Key Projects of the National Natural Science Foundation of China(Grant No.U23A20678)the Scientific Research and Innovation Team Project of Hebei University(Grant No.IT2023B03)the Post-graduate’s Innovation Fund Project of Hebei University(Grant No.HBU2024BS007)。
文摘Shear rheology is a fundamental property of soft matter,which can be deformed.Although the shear rheology of fluids has been well studied at the macroscopic scale,understanding the microscopic processes of rheology at the single-particle level remains a challenging issue.Dusty plasma serves as an ideal platform for exploring microscopic dynamics of system at the individual particle level.Here,we study the shear rheology of confined double rings of strongly coupled dust particles in a dusty plasma.The outer ring is actively driven to rotate using laser illumination.Depending on the particle number,the inner ring may passively rotate following the outer ring at different angular speeds,resulting in shear rheology.The number of dust particles influences particle arrangement,which is characterized by the pair correlation function,bond-orientational order parameter,and triangle skewness.That further alters structural stability,significantly affecting the shear rheology.
基金Supported by the NSFC Innovative Research Group(51821092)NSFC Foundation(52004297)+1 种基金China Postdoctoral Science Foundation(BX20200384)China University of Petroleum(Beijing)Foundation(2462020XKBH00)。
文摘As the base oil of the current flat-rheology synthetic drilling fluid is high in cost and not renewable, the biodiesel-based flat-rheology drilling fluid with low-cost, environmental protection and renewable advantage was studied. Based on the optimization of raw materials, a cheap, environment-friendly biodiesel of soybean oil ethyl ester with good fluidity at low temperature was selected as the base oil. By selecting high oil-water ratio and introducing cationic surfactant into the auxiliary emulsifier, the thickening of biodiesel-based emulsion caused by hydrolysis and saponification after high-temperature aging was effectively eliminated. The organoclay prepared with cationic modifier of hexadecyl trimethyl ammonium chloride was used to improve the rheologic properties, stability and fluid loss of the drilling fluid while preventing low-temperature thickening. A flat-rheology modifier was synthesized with dimer fatty acid and cocoanut fatty acid diethanolamide, which could form strong network structure in the biodiesel-based drilling fluid to adjust effectively rheological properties of the drilling fluid. A biodiesel-based flat-rheology drilling fluid system with the density of 1.2 g/cm^(3) has been formulated which has constant rheology in the temperature range of 2-90 ℃, temperature tolerance of 160 ℃, seawater salinity tolerance of 5%, shale cuttings tolerance of 10%, and is environmentally friendly.
基金the strong and long-term support from the National Natural Science Foundation of China (Grant Nos. 51134006, 50944030)the Ministry of Education (Grant No. 104118)+2 种基金Beijing Municipal Education Commission (Grant No. YB20081141401)companies such as China National Petroleum Corporation (CNPC)China Petrochemical Corporation (SINOPEC)
文摘Flow assurance is one of the core issues in safe and economical operation of waxy crude pipelines.Its essence lies in flow and heat transfer of the crude.In the past 10 years,the authors＇ team has achieved a lot of innovative results in aspects of waxy crude rheology,flow assurance assessment,and pipelining technologies on the basis of decades of studies.The rheological characteristics of waxy crude are much better understood,and a method for quantitatively simulating the effect of flow shear was developed based on some theoretical breakthroughs.Studies of the mechanism of waxy crude rheology have been deepened to the quantitative level.After successful development of efficient numericalalgorithms,accurate simulations have been achieved for various complex flow and heat transfer situations in waxy crude pipelining,and a reliability-based approach to flow assurance assessment has been set up.New pipelining technologies have been developed such as batching pour-point depressant-（PPD-） treated multiple-waxy-crudes,intermittent transport of waxy crudes through long-distance pipelines,and batching hot and cold crudes.By their application,a series of problems hindering safe,efficient and flexible operation of waxy crude pipelines were tackled,demonstrating that transportation technologies for waxy crude have advanced to a new and high level.
基金Supported by Independent Research Projects of State Key Laboratory of Explosion Science and Technology(ZDKT08-05)
文摘Structure of emulsifiers or functionality and molecular weight determines its rheology, emulsification and stability of emulsion explosives. Rheology of typical emulsifiers was studied by automatic rheometer. Relations between rheology and structural properties of typical emulsifiers were analyzed. Experimental results show that viscosity of emulsifiers didn＇ t change with shear rate at room temperature and appeared properties of Newtonian fluid. Viscosity of different component emulsifiers declines with temperature in different modes. The change of strain doesn＇ t affect modu- lus of emulsifiers. Loss modulus increases linearly with the increase of frequency in oscillation and storage modulus does non-linearly. The higher the temperature is, the lower change amplitude of loss modulus with frequency will be. The emulsifiers with imide and amide functionality for emulsion explosives have better shear properties at high temperature and better shapingness and stability at room temperature than other emulsifiers with ester and Sorbin Monoleate （SMO） functionality.
基金RWTH Aachen UniversityChina University of Petroleum for the support of the work+1 种基金funded by the startup project of China University of Petroleum, Beijing (No.2462014YJRC041)supported by Science Foundation of China University of Petroleum, Beijing (No. C201601)
文摘Numerical modeling of salt tectonics is a rapidly evolving field; however, the constitutive equations to model long-term rock salt rheology in nature still remain controversial. Firstly, we built a database about the strain rate versus the differential stress through collecting the data from salt creep experiments at a range of temperatures（20–200 ℃） in laboratories. The aim is to collect data about salt deformation in nature, and the flow properties can be extracted from the data in laboratory experiments.Moreover, as an important preparation for salt tectonics modeling, a numerical model based on creep experiments of rock salt was developed in order to verify the specific model using the Abaqus package. Finally, under the condition of low differential stresses, the deformation mechanism would be extrapolated and discussed according to microstructure research. Since the studies of salt deformation in nature are the reliable extrapolation of laboratory data, we simplified the rock salt rheology to dislocation creep corresponding to power law creep（n = 5） with the appropriate material parameters in the salt tectonic modeling.
文摘Polymer injectivity is an important factor for evaluating the project economics of chemical flood,which is highly related to the polymer viscosity.Because the flow rate varies rapidly near injectors and significantly changes the polymer viscosity due to the non-Newtonian rheological behavior,the polymer viscosity near the wellbore is difficult to estimate accurately with the practical gridblock size in reservoir simulation.To reduce the impact of polymer rheology upon chemical EOR simulations,we used an efficient multilevel local grid refinement（LGR）method that provides a higher resolution of the flows in the near-wellbore region.An efficient numerical scheme was proposed to accurately solve the pressure equation and concentration equations on the multilevel grid for both homogeneous and heterogeneous reservoir cases.The block list and connections of the multilevel grid are generated via an efficient and extensible algorithm.Field case simulation results indicate that the proposed LGR is consistent with the analytical injectivity model and achieves the closest results to the full grid refinement,which considerably improves the accuracy of solutions compared with the original grid.In addition,the method was validated by comparing it with the LGR module of CMG_STARS.Besides polymer injectivity calculations,the LGR method is applicable for other problems in need of near-wellbore treatment,such as fractures near wells.
文摘The present study investigates the effects of incorporating oat bran(OB) into Chinese steamed bread(CSB). Different levels(5%, 10% and 15%) of OB were used to replace wheat flour in the manufacture of CSB. The rheological properties of the dough were measured(water absorption(WA), development time, mixing tolerance, extensibility and stickiness). The addition of OB significantly increased WA, development time and stickiness, whereas decreased extensibility of dough. The physical properties of CSB were determined using specific volume, loaf height, moisture, and texture analysis. The nutritional quality of the bread was also analysed using an in vitro digestion method mimicking intestinal digestion. The results illustrated that the incorporation of OB into wheat flour decreases specific volume and softness of CSB. The addition of OB decreased the glycaemic response of steamed bread.This study illustrates the potential addition of OB to improve the nutritional quality of CSB.
基金the financial support from the National Natural Science Foundation of China and the start-up projectthe Sichuan-University-Dazhou Joint project(00309053A2037)+1 种基金the Fundamental Research Funds for the Central Universitiespartially sponsored by the Double First-Class Construction Funds of Sichuan University。
文摘The microstructures on electrode level are crucial for battery performance, but the ambiguous understanding of both electrode microstructures and their structuring process causes critical challenges in controlling and evaluating the electrode quality during fabrication. In this review, analogous to the cell microenvironment well-known in biology, we introduce the concept of ‘‘active material microenvironment”(ME@AM)that is built by the ion/electron transport structures surrounding the AMs, for better understanding the significance of the electrode microstructures. Further, the scientific significance of electrode processing for electrode quality control is highlighted by its strong links to the structuring and quality control of ME@AM. Meanwhile, the roles of electrode rheology in both electrode structuring and structural characterizations involved in the entire electrode manufacturing process(i.e., slurry preparation, coating/printing/extrusion, drying and calendering) are specifically detailed. The advantages of electrode rheology testing on in-situ characterizations of the electrode qualities/structures are emphasized. This review provides a glimpse of the electrode rheology engaged in electrode manufacturing process and new insights into the understanding and effective regulation of electrode microstructures for future high-performance batteries.
文摘The melt rheological behaviors of the PET/E-HDP(for short of Easily Hydrolyzed and Easily Dyed Polyester) blending systems at different blending ratios were investigated by the capillary rheometer. The E-HDP is derived from polyethylene terephathalate (PET) modified through copolycondensation with sulfonate moiety, (sodiosulfo) isophthalate (Na-SIP) and iso-phthalic acid(IPA). The results showed that the apparent viscosity and non-Newtonian index of the PET/E-HDP blend system had the non-linearity change with the change of the blend ratio of PET/E-HDP. The anomaly of the viscous flow activation energy change was founded as the mass fraction of E-HDP was about 40% in the blend system,suggesting the presence of reversible crosslinked structure formed by strong polar tangling points and the phase separation owing to poor compatibility between the PET and
基金the support from the University of South Carolina
文摘Helical hierarchy found in biomolecules like cellulose,chitin,and collagen underpins the remarkable mechanical strength and vibrant colors observed in living organisms.This study advances the integration of helical/chiral assembly and 3D printing technology,providing precise spatial control over chiral nano/microstructures of rod-shaped colloidal nanoparticles in intricate geometries.We designed reactive chiral inks based on cellulose nanocrystal(CNC)suspensions and acrylamide monomers,enabling the chiral assembly at nano/microscale,beyond the resolution seen in printed materials.We employed a range of complementary techniques including Orthogonal Superposition rheometry and in situ rheo-optic measurements under steady shear rate conditions.These techniques help us to understand the nature of the nonlinear flow behavior of the chiral inks,and directly probe the flow-induced microstructural dynamics and phase transitions at constant shear rates,as well as their post-flow relaxation.Furthermore,we analyzed the photo-curing process to identify key parameters affecting gelation kinetics and structural integrity of the printed object within the supporting bath.These insights into the interplay between the chiral inks self-assembly dynamics,3D printing flow kinematics and photopolymerization kinetics provide a roadmap to direct the out-of-equilibrium arrangement of CNC particles in the 3D printed filaments,ranging from uniform nematic to 3D concentric chiral structures with controlled pitch length,as well as random orientation of chiral domains.Our biomimetic approach can pave the way for the creation of materials with superior mechanical properties or programable photonic responses that arise from 3D nano/microstructure and can be translated into larger scale 3D printed designs.
基金supported by the Open Fund of Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs(No.KFJJ-TZ-2020-2)the National Natural Science Foundation of China(No.52104030)+1 种基金the Key Research and Development Program of Shaanxi(No.2022 KW-35)the China Fundamental Research Funds for the Central Universities。
文摘Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental concerns.Here,we report a microfluid displacement technology containing a bio-based eco-friendly material,i.e.,calcium alginate(CaAlg)microspheres for EOR.Two dominant mechanisms responsible for EOR over Ca Alg fluid have been verified,including the microscopic oil displacement efficacy augmented by regulating capillary force(determined by the joint action of interfacial tension and wettability between different phases)and macroscopic sweep volume increment through profile control and mobility ratio reduction.This comprehensive effectiveness can be further impacted when the CaAlg microsphere is embellished ulteriorly by using appropriate amount of sodium dodecyl sulfonate(SDS).The core flooding and nuclear magnetic resonance(NMR)tests demonstrate that CaAlg-SDS microsphere can balance the interphase property regulation(wettability alteration and IFT reduction)and rheology properties,enabling simultaneous profile control and oil displacement.Excessive introduction of SDS will have a negative impact on rheological properties,which is not favored for EOR.Our results show that the involvement of 4-m M SDS will provide the best behavior,with an EOR rate of 34.38%.This cost-effective and environmentally-friendly bio-microspherebased microfluidic displacement technology is expected to achieve“green”oil recovery in future oilfield exploitation.
基金supported by the Hunan Provincial Natural Science Foundation of China (Grant no.2023JJ30632)National Key R&D Program (Grant no.2022YFC2204403)Key R&D Program of Hunan Province (Grant no.2022GK2027)。
文摘Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shaping of carbon aerogels with tailored micro-nano structural textures and geometric features.Herein,a facile extrusion 3D printing strategy has been proposed for fabricating CNT-assembled carbon(CNT/C)aerogel nanocomposites through the extrusion printing of pseudoplastic carbomer-based inks,in which the stable dispersion of CNT nanofibers has been achieved relying on the high viscosity of carbomer microgels.After extrusion printing,the chemical solidification through polymerizing RF sols enables 3D-printed aerogel nanocomposites to display high shape fidelity in macroscopic geometries.Benefiting from the micro-nano scale assembly of CNT nanofiber networks and carbon nanoparticle networks in composite phases,3D-printed CNT/C aerogels exhibit enhanced mechanical strength(fracture strength,0.79 MPa)and typical porous structure characteristics,including low density(0.220 g cm^(-3)),high surface area(298.4 m^(2)g^(-1)),and concentrated pore diameter distribution(~32.8nm).More importantly,CNT nanofibers provide an efficient electron transport pathway,imparting 3D-printed CNT/C aerogel composites with a high electrical conductivity of 1.49 S cm^(-1).Our work would offer feasible guidelines for the design and fabrication of shape-dominated functional materials by additive manufacturing.
基金This work was financially supported by the National Natural Science Foundation of China(U20A20256,51973207)the NSAF Joint Fund(U2030203).
文摘The general development of Rheo-NMR during the last four decades as well as selective hyphenated apparatuses is presented.Based on different magnet types,the current review is divided into two categories,namely low-field and high-field NMR,while the timedomain NMR is normally applied in the former case and the frequency-domain NMR is adopted in the latter one.Depending on different rheometer cells,it can be further divided into tensile and shear mode Rheo-NMR.The combination of various rheometer cells and NMR facility guarantees our acquisition of molecular level structure and dynamics information under flow conditions,which is crucial for our understanding of the molecular origin of complex fluids.A personal perspective is also presented at last to highlight possible development in this direction.
文摘Objective:To evaluate the effect of Shen Rou Yang Zhen Decoction on blood rheology of the patients with Piyinxu. Methods:30 cases of patients with Piyinxu were treated with Shen Rou Yang Zhen Decoction.The blood rheology was detected before and after treatment. Results:30 cases of patients with Piyinxu were treated for one course of treatment resulting in obvious efficiency in 9 cases(30 % ), efficiency in 19 cases(63.33 % ), inefficiency in 2 cases (6.67%). The overall effective rate was 93.33%. The indexes of blood rheology including blood viscosity and plasma viscosity were significantly reduced (P ＜ 0.01). Conclusions: Shen Rou Yang Zhen Decoction can reduce the blood viscosity and improve the blood rheology in patients with Piyinxu.
基金This research was partially funded by Mining Education Australia(MEA)and OZ Minerals,Australiatheir support is gratefully acknowledged.
文摘The pumping ability and placement performance of fresh cemented paste backfill(CPB) in underground mined cavities depend on its rheological properties. Hence, it is crucial to understand the rheology of fresh CPB slurry, which is related to CPB mixture design and the temperature underground. This paper presented an experimental study investigating the effects of binder type, content, water chemical properties and content, and temperature, on the rheological properties of CPB material prepared using the tailings of a copper mine in South Australia. Portland cement(PC), a newly released commercially manufactured cement called Minecem(MC) and fly ash(FA) were used as the binders added to the mine tailing materials. Various amounts of two different water types were added to the mixtures in the preparation of backfill material slurry. Six different temperatures ranging from 5 to 60 °C were to investigate the effect of temperature on CPB rheology. Overall, the increasing water content and decreasing temperature lead to lower yield stress. Based on the results obtained from the rheological properties of CPB slurry, it was found that at room temperature(25 °C), with regards to the unconfined compressive strength(UCS) performance, the replacement of 4% PC mixed CPB(28 days UCS 425 k Pa) to 3% MC mixed CPB(28 days UCS 519 k Pa), reduced the slurry yield stress from 210.7 to 178.5 Pa. The results also showed that the chemical composition of water affects the yield stress of CPB slurry and that MC mitigates the negative effect of mine-processed water(MW) and thus lead to improve the rheological properties of the slurry. However, the results suggested that the rheological properties of a mixture using MC is very sensitive to the water volume and temperature change. Therefore, using MC in backfill requires better quality control in slump mixing.
文摘An oil-based drilling fluid should be stable and tolerant to high temperatures for use in deep drilling. An invert emulsion of water in oil is a good choice as an oil- based drilling fluid which is a mixture of a solid phase and two immiscible liquid phases stabilized by a polymeric surfactant. In deep drilling, due to high temperatures, the polymeric surfactant degrades and a phase separation occurs. Here, octadecyltrimethoxysilane-modified silica nanoparticles were used to form a stable invert emulsion of water in oil for the drilling fluid model which resulted in a milky fluid with the formation of 60 gm water droplets. In addition, rheological study showed that using hydrophobic silica nanoparticles resulted in a stable water in oil invert emulsion with desired properties for a drilling fluid that can be modified by adjusting the nanoparticle nature and content. Aging experiments at 120 ℃ indicated that they also have good stability at high temperatures for challenging drilling operations.
基金the support provided by the Deanship of Scientific Research(DSR)at King Fahd University of Petroleum&Minerals(KFUPM)for funding this work through Project No.IN 141008
文摘Excellent drilling fluid techniques are one of the significant guaranteed measures to insure safety, qual- ity, efficiency, and speediness of drilling operations. Dril- ling fluids are generally discarded after the completion of drilling operations and become waste, which can have a large negative impact on the environment. Drilling mate- rials and additives together with drill cuttings, oil, and water constitute waste drilling fluids, which ultimately are dumped onto soil, surface water, groundwater, and air. Environmental pollution is found to be a serious threat while drilling complex wells or high-temperature deep wells as these types of wells involve the use of oil-based drilling fluid systems and high-performance water-based drilling fluid systems. The preservation of the environment on a global level is now important as various organizations have set up initiatives to drive the usage of toxic chemicals as drilling fluid additives. This paper presents an approach where grass is introduced as a sustainable drilling fluid additive with no environmental problems. Simple water- based drilling fluids were formulated using bentonite, powdered grass, and water to analyze the rheological and filtration characteristics of the new drilling fluid. A particle size distribution test was conducted to determine the par- ticle size of the grass sample by the sieve analysis method. Experiments were conducted on grass samples of 300, 90, and 35 μm to study the characteristics and behavior of the newly developed drilling fluid at room temperature. The results show that grass samples with varying particle sizes and concentrations may improve the viscosity, gel strength, and filtration of the bentonite drilling fluid. These obser- vations recommend the use of grass as a rheological modifier, filtration control agent, and pH control agent to substitute toxic materials from drilling fluids.
文摘A temperature-resistant, salt-tolerant polyacrylamide, hydrophobically associating polymer （HAP）, was synthesized in the State Key Laboratory of Heavy Oil Processing. The rheological behavior of HAP solution was investigated by means of flow experiments in porous media and by using a HAAKE RS600 rheometer. The results of Nuclepore membrane filtration showed that filtration time increased sharply when the critical association concentration was reached. Shear rate had a greater impact on viscosity and shear stress with increasing HAP concentration. The HAP solution with a concentration of 100 mg/L （salinity 32,868 mg/L） exhibited negative thixotropy. However, at the same salinity the HAP solution showed thixotropy and its viscosity became greater when the polymer concentration increased to 1,500 mg/L. The flow experiments in cemented core samples indicated that the resistance factor and residual resistance factor of the HAP solution were 31.8 and 12 when polymer concentration and salinity were 1,500 mg/L, 32,868 mg/L at 85℃ respectively, which is favorable for flooding application. Such factors of partially hydrolyzed polyaerylamide 3530S were merely 3.14 and 1.71, so it could not be applied to polymer flooding in the oilfield with high temperature and high salinity.
基金the Indian Institute of Technology (Indian School of Mines), Dhanbad for providing necessary laboratory facilities and financial support
文摘The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.
文摘Colloidal gas aphrons (CGAs) were first reported by Sebba (1971) as micro bubbles (25-125 μm), composed of a gas nucleus surrounded by a thin surfactant film and created by intense stirring of a surfactant solution. Since then, these colloidal dispersions have been used for diverse applications, with a particular focus on separation processes. However, exploitation of CGAs in petroleum industry is only at the outset. CGAs were first used in west Texas in 1998, under the name Aphron drilling fluids. This kind of fluid is characterized as having a continuous phase, a high viscosity at a low shear rate and containing, as an internal phase, micro air or gas bubbles, non-coalescing and recirculating. In this paper, we illuminate the physical and chemical properties of aphron drilling fluid and its processing mechanism.
