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Aerodynamics of a Tandem-Bladed Axial Compressor Rotor under Circumferential distortion at different Rotational Speeds

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Journal of Thermal Science 2024年第4期33卷 1340-1356页

作者： Amit KUMAR Jerry T.john A.M.PRAdEEP R.A.dAKKERMANS dragan KOZULOVIC department of Aerospace Engineering Indian Institute of Technology BombayMumbai400076India department of Automotive and Aeronautical Engineering Hamburg University of Applied Sciences20099HamburgGermany Institute of Jet Propulsion Bundeswehr University Munich85577NeubibergGermany

For most aircraft engines,inflow distortion is *** distortion is known to degrade the aerodynamic performance and stable operating limits of a *** rotor configuration is an arrangement that effectively controls the growth of the boundary layer over the suction surface of the ***,a higher total pressure rise can be achieved through this unconventional design approach involving the splitting of the blade into forward and aft *** is expected that the effect of inlet flow distortion would be more severe for a tandem-rotor design due to the greater flow turning inherent in such ***,this aspect needs to be thoroughly *** present study discusses the effect of circumferential distortion on the tandem-rotor at different rotational ***-annulus RANS simulations using ANSYS CFX are used in the present *** performance of the rotor at a particular flow coefficient and different rotational speeds is *** total pressure and efficiency are observed to drop at lower mass flow rates under the influence of circumferential *** loss region in each blade passage is mainly associated with the blade wake,tip leakage vortex,secondary flow,and boundary ***,their contribution varies from passage to passage,particularly in the distorted *** the lower span,the wake width is found to be higher than that at a higher *** to the redistribution of the mass flow,the circumferential extent reduces at a higher *** the undistorted sector,the strength of the tip leakage vortex is significantly higher at the design rotational speed than at lower *** distortion near the tip region promotes an early vortex breakdown even at the design operating *** adversely affects the total pressure,efficiency,and stall *** clean flow conditions,this phenomenon is only observed near the stall *** the design operating condition,the breakdown of the forward rotor tip l

关键词： tandem rotor circumferential distortion loss tip leakage vortex vortex breakdown diffusion factor aerodynamics of compressor blade

Challenges and Opportunities in Preserving Key Structural Features of 3d-Printed Metal/Covalent Organic Framework

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Nano-Micro Letters 2024年第8期16卷 362-381页

作者： Ximeng Liu dan Zhao john Wang department of Materials Science and Engineering National University of SingaporeSingapore 117574Singapore department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore National University of Singapore(Chongqing)Research Institute Chongqing 401123People’s Republic of China

Metal-organic framework(MOF)and covalent organic framework(COF)are a huge group of advanced porous materials exhibiting attractive and tunable microstructural features,such as large surface area,tunable pore size,and functional surfaces,which have significant values in various application *** emerging 3d printing technology further provides MOF and COFs(M/COFs)with higher designability of their macrostructure and demonstrates large achievements in their performance by shaping them into advanced 3d ***,the currently available 3d printing M/COFs strategy faces a major challenge of severe destruction of M/COFs’microstructural features,both during and after 3d *** is envisioned that preserving the microstructure of M/COFs in the 3d-printed monolith will bring a great improvement to the related *** this overview,the 3d-printed M/COFs are categorized into M/COF-mixed monoliths and M/COF-covered *** differences in the properties,applications,and current research states are *** up-to-date advancements in paste/scaffold composition and printing/covering methods to preserve the superior M/COF microstructure during 3d printing are further discussed for the two types of 3d-printed M/*** the analysis of the current states of 3d-printed M/COFs,the expected future research direction to achieve a highly preserved microstructure in the 3d monolith is proposed.

关键词： Metal-organic frameworks Covalent organic frameworks 3d printing Microstructure Monolith

Geothermal extraction performance in fractured granite from Gonghe Basin,Qinghai province,China:Long-term injection and production experiment

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第2期3卷 111-123页

作者： Haiyan Zhu Shijie Chen Qiang Fu Peng Zhao john d.McLennan State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina College of Energy Chengdu University of TechnologyChengdu610059SichuanChina CNOOC Research Institute Co. Ltd.Beijing100028China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China department of Chemical Engineering University of UtahSalt Lake CityUT84105United States

The efficient exploitation of geothermal energy through enhanced geothermal systems(EGS)has been a relevant topic for hot dry rock(HdR)geothermal *** cryogenic fluid is injected into a thermal reservoir,improving heat exchange efficiency is key to achieving the optimal exploitation of *** this paper,granite outcrops from Gonghe Basin were used as the testing *** natural fractures in the granite samples were relatively well *** simulate long-term injection and production from multi-wells in situ,physical ex-periments were performed in a newly-developed,in-house large-scale true triaxial experimental *** extraction performance of an HdR was simulated for long-term injection and production ***,the mode of one-injection and multiple-production wells was *** the paper,the ef-fects of the production-injection well spacing,the number of production wells and the injection rate on the production temperature and flow rate are *** results show that,during long-term injection and pro-duction,there are two stages of production temperature variation,namely stabilization and *** the number of the production wells is increased,the heat extraction efficiency is ***,competitive diversion of fluid among fractures occurred due to different ***,under different pro-duction modes,the production flow rate contributed differently to the heat ***,the effect of the production-injection wells spacing on the heat exchange performance was analyzed;this is mainly reflected in the change of the effective heat exchange area between the rock and the injected *** results emphasize the importance of designing an appropriate production mode and optimizing the injection-production parameters to ensure efficient HdR exploitation.

关键词： Enhanced geothermal system(EGS) Long-term injection and production experiment One-injection and multiple-productions mode Large-scale physical simulation experiment Heat extraction performance

Experimental and analytical investigation on friction resistance force between buried coated pressurized steel pipes and soil

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 615-629页

作者： Shaurav ALAM Tanvir MANZUR john MATTHEWS Chris BARTLETT Erez ALLOUCHE Brent KEIL john KRAFT department of Civil Engineering and Construction Engineering Technology Louisiana Tech UniversityRustonLA 71270USA department of Civil Engineering Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh Georgia Tech Research Institute AtlantaGA 30332USA Stantec Inc. Edmonton T5J0K4Canada North West Pipe Company VancouverWA 98684USA

This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust *** proposed analytical method was developed based on 36 experiments,which involved three coating types(cement mortar(CM),polyurethane type-I(PT-I),prefabricated plastic tape(PPT))on pipes’surfaces,three different soils(pea-gravel(PG),sand(S),silty-clay(SC)),and four simulated over burden depths above the pipe’s *** showed frictional resistance decreased with increasing over burden depth above the pipe’s *** degree of frictional resistance at the pipe-soil interface was found to be in the order of PG>SC>S for all coating variations and overburden *** coated pipe buried in all three types of soil produced significantly higher frictional resistance as compared to other coating *** on experimental data,the developed analytical introduced a dimensionless factor“Z”,which included effects of types of coatings,soil,and overburden depths for simplified rapid *** showed that the method provided a better prediction of frictional resistance forces,in comparison to previous analytical methods,which were barely close in predicting friction resistance for different coating variations,soil types,and overburden *** resistance force values reported herein could be considered conservative.

关键词： friction resistance force thrust force coated pressurized steel pipe soil type overburden depth

A Population dynamics Approach to the distribution of Space debris in Low Earth Orbit

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Communications on Applied Mathematics and Computation 2024年第1期6卷 340-353页

作者： john Jurkiewicz Peter Hinow department of Mathematical Sciences University of Wisconsin-MilwaukeeMilwaukeeWI53201USA

The presence of the debris in the Earth’s orbit poses a significant risk to human activity in outer *** debris population continues to grow due to ground launches,the loss of external parts from space ships,and uncontrollable collisions between objects.A computationally feasible continuum model for the growth of the debris population and its spatial distribution is therefore *** we propose a diffusion-collision model for the evolution of the debris density in the low-Earth orbit and its dependence on the ground-launch *** parametrize this model and test it against data from publicly available object catalogs to examine timescales for the uncontrolled ***,we consider sensible launch policies and cleanup strategies and how they reduce the future risk of collisions with active satellites or space ships.

关键词： Population dynamics Space debris Kessler syndrome diffusion Low-Earth orbit

Surgical treatment of inflammatory bowel disease:From the gastroenterologist’s stand-point

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1235-1254页

作者： john K Triantafillidis Inflammatory Bowel disease Unit “Metropolitan General”HospitalHolargos 15562AtticaGreece Hellenic Society of Gastrointestinal Oncology Haidari 12461AthensGreece

Treatment of ulcerative colitis(UC)and Crohn’s disease(Cd)represents,in the majority of cases,a real challenge to the gastroenterologist’s abilities and skills as well as a clinical test concerning his/her levels of medical knowledge and *** the last two decades,our pharmaceutical arsenal was significantly strengthened,especially after the introduction of the so-called biological agents,drugs which to a large extent not only improved the results of conservative treatment but also changed the natural history of the ***,colectomy is still necessary for some patients with severe UC although smaller compared to the past,precisely because of the improvements achieved in the available conservative ***,surgeries to treat colon dysplasia and cancer are increasing to some *** the same time,satisfactory improvements in surgical techniques,the pre-and post-operative care of patients,as well as the selection of the appropriate time for performing the surgery have been *** patients with Cd,the improvement of conservative treatment did not significantly change the need for surgical treatment since two-thirds of patients need to undergo surgery at some point in the course of their *** the other hand,the outcome of the operation has improved through good preoperative care as well as the wide application of more conservative surgical techniques aimed at keeping as much of the bowel in situ as *** article discusses the indications for surgical management of UC patients from the gastroenterologist’s point of view,the results of the emerging new techniques such as transanal surgery and robotics,as well as alternative operations to the classic ileo-anal-pouch *** author also discusses the basic principles of surgical management of patients with Cd based on the results of the relevant *** self-evident is emphasized,that is,to achieve an excellent therapeutic result in patients with se

关键词： Inflammatory bowel disease Ulcerative colitis Crohn’s disease Surgery Treatment Ileo-anal-pouch anastomosis Indications Techniques

Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.S.john B.MAHANTHESH G.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India School of Mathematical and Statistical Sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

does photobiomodulation require glucose to work effectively?

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Neural Regeneration Research 2024年第5期19卷 945-946页

作者： Jaimie Hoh Kam john Mitrofanis UniversitéGrenoble Alpes Fonds de Dotation ClinatecGrenobleFrance University College London Institute of OphthalmologyUK

A main requirement for cells to function normally is the availability of ***,available either direct from circulation or storage,is converted to the essential energy that cells need to drive critical intrinsic *** cells are deprived of glucose,they become dysfunctional and suffer ***,the use of specific wavelengths of light on body tissues,has been shown to promote,through small organelles called mitochondria,the metabolism of glucose to make energy for cells;this energy can be used to improve cell function and *** this perspective,we hypothesize that the availability of glucose is central to the core mechanism of photobiomodulation;that photobiomodulation is at its most efficient in stimulating mitochondrial activity and improving cell function when there is glucose readily available.

关键词： metabolism distress stimulating

Optimizing oncolytic virus design:a“Swiss army knife”approach to create a systemically delivered therapeutic

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Signal Transduction and Targeted Therapy 2024年第5期9卷 1791-1792页

作者： Carolina S.Ilkow john Cameron Bell Ottawa Hospital Research Institute 501 Smyth RoadOttawaONK1H 8L6Canada

In a recent paper published in Nature Biotechnology,Chen et al.1 describe a multiplex oncolytic virus platform that coupled with adoptive T cell therapy could solve the problem of repeat,systemic delivery of virus based *** is widely accepted that multi-targeted therapeutic approaches attacking several facets of cancer biology are necessary to effectively deal with the tumor heterogeneity that exists within and between patients.

关键词： therapeutic al. targeted