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Coating powder beds with liquids and foams based on viscous formulations using a twin screw mixer:A continuous process study

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particuology 2024年第10期93卷 364-376页

作者： Mohamed S.Manga Dimitrios Kontziampasis Mustafa Al-Maqdad sean Clifford Serafim Bakalis david W.York School of Chemical and process Engineering Faculty of Engineering and Physical SciencesUniversity of LeedsLeedsLS29JTUK School of Mechanical Engineering Faculty of Engineering and Physical SciencesUniversity of LeedsLeedsLS29JTUK School of Science and Engineering University of DundeeDD14HNDundeeScotlandUK Dundee International Institute of Central South University Tongzipo RoadCentral South UniversityChangshaHunan410013China Department of Chemical Engineering School of EngineeringUniversity of NewcastleNewcastleNE17RUUK School of Chemical Engineering University of BirminghamBirminghamB152TTUK Department of Chemical Engineering Faculty of EngineeringUniversity of NottinghamNG72RDUK

Coating with viscous formulations has been essential in numerous industries as it can be a means for providing functionalization, additional properties, as well as other benefits. However, there have been scarce studies that have investigated and proposed methodologies in literature. Continuous coating of powders with viscous liquids poses as a promising technology, which has been mentioned in some studies, but has not yet been thoroughly investigated. This paper employs the use of image processing and analysis, in combination with statistical analysis of particles to evaluate the effectiveness of foams and liquids as a means of coating powder beds. Two different sizes of twin screw mixers that are working in continuous operation are employed, and a new continuous foaming device is fabricated and used for the experiments of coating. The effect of materials and process parameters (as for example rotational speed, and flowrate) on the quality of coating are investigated. Image analysis is used to assess the coating quality. The results clearly showcase the potential of using twin screw mixers for coating purposes and not only for mixing. The hypothesis that using large bubble foams to improve the coating of viscous liquids on particles is proven correct, as they provide higher quality coatings compared to their equivalent liquids, when used in the twin screw mixer. Surprisingly, using a larger scale twin screw mixer, does not show a substantial effect on the mixing, regarding quality, however there is still a requirement for mix optimization for achieving scale-up of this process. These results provide a new pathway for coating powders with viscous formulations in industrial applications, requiring less energy and effort in this process, and can pave the way towards introducing more sustainable industrial methodologies for coating.

关键词： powder coating Continuous processing Viscous liquid Foam Image analysis positron emission particle traking(pEpT)

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Direct-to-indirect mapping for optimal low-thrust trajectories

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Astrodynamics 2024年第1期8卷 27-46页

作者： david Ottesen Ryan p.Russell Department of Aerospace Engineering and Engineering Mechanics The University of Texas at AustinAustinTexas78712USA

Optimal,many-revolution spacecraft trajectories are challenging to solve.A connection is made for a class of models between optimal direct and indirect *** transfers that minimize thrust-acceleration-squared,primer vector theory maps direct,many-impulsive-maneuver trajectories to the indirect,continuous-thrust-acceleration *** mapping algorithm is independent of how the direct solution is obtained and requires only a solver for a boundary value problem and its partial derivatives.A Lambert solver is used for the two-body problem in this *** mapping is simple because the impulsive maneuvers and co-states share the same linear space around an optimal *** numerical results,the direct coast-impulse solutions are demonstrated to converge to the indirect continuous solutions as the number of impulses and segments *** two-body design space is explored with a set of three many-revolution,many-segment examples changing semimajor axis,eccentricity,and *** first two examples involve a small change to either semimajor axis or eccentricity,and the third example is a transfer to geosynchronous *** a single processor,the optimization runtime is seconds to minutes for revolution counts of 10 to 100,and on the order of one hour for examples with up to 500 *** of these thrust-acceleration-squared solutions are good candidates to start a homotopy to a higher-fidelity minimization problem with practical constraints.

关键词： direct optimization indirect optimization impulsive maneuvers Lambert's problem two-body dynamics primer vectortheory

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Seasonal changes in Hermit Thrush (Catharus guttatus) song syntax

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Avian Research 2024年第2期15卷 172-179页

作者： sean p.Roach Luke C.McLean Jeff W.MacLeod Leslie S.phillmore psychology Department University of New Brunswick Saint John100 Tucker Park RoadSaint JohnNBCanada Department of psychology and Neuroscience Dalhousie University1355 Oxford StHalifaxNSB3H 4J1Canada

In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a *** such syntactical patterns have been richly described in many species,comparatively little is known about how those patterns contribute to song achieving its important *** each of song’s main functions,territorial defense and mate attraction,evidence of a role for syntax is *** species for which syntax has been thoroughly described is the Hermit Thrush(Catharus guttatus),which presents song types from their repertoires in a semi-predictable order and,in doing so,rapidly cycle up and down the frequency *** objective of the present study was to explore the importance of song syntax in the Hermit Thrush through a within-subject examination of how measures of syntax,such as the predictability of song type order within song sequences,shift over the breeding *** hypothesized that,if such syntactical characteristics are important to breeding behaviour,they would be most prominent at the start of the breeding season when activity associated with territory establishment and mate attraction is most *** revealed that,as predicted,the rigidness of song type ordering within se-quences was highest at the start of the season and declined *** song type sequences were most predictable at the vitally important early part of the breeding season fit our hypothesis that this aspect of song syntax is important to song’s functions related to territory establishment and/or mate *** work will clarify whether that role relates to one of song’s two main functions or serves song transmission in some broader way.

关键词： Birdsong Hermit Thrush Seasonal change Stereotypy Syntax

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The great catastrophe: causes of the permo-Triassic marine mass extinction

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National Science Review 2024年第1期11卷 37-50页

作者： paul B.Wignall david p.G.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(pid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

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A combined experimental and DEM investigation of grain interlocking in sheared granular assemblies

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particuology 2024年第7期90卷 436-451页

作者： Rui Lu Qiang Luo Tengfei Wang david p.Connolly Tao Xie School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-Speed Railway Engineering(Southwest Jiaotong University) Ministry of EducationChengdu 610031China School of Civil Engineering University of LeedsLeeds LS29JTUK Department of Civil Engineering McMaster UniversityHamiltonONCanada

Compacted granular material,integral to geotechnical engineering,undergoes translation,rotation,and interlocking when subject to shear displacements or external *** present study focuses on the interlocking of heterogeneous granular materials,a complex behavior influenced by gradation,compaction,and varying particle geometry,and has consequently received limited attention in existing *** address this research gap,we conducted an analysis on the effect of grain interlocking on the shear resistance of granular assemblies,using a combination of laboratory testing and the discrete element method(DEM).Initially,large-scale direct shear tests were conducted on gravel−sand mixes with varying degrees of compaction and normal *** of the mixes also underwent subsequent shear reversal to explore the differences in grain interlocking between the two shearing processes on the shear *** analyzing the laboratory results,a mesoscopic scale investigation was performed by replicating the test using discrete element *** facilitate this,granular particle geometries were measured using 3D laser scanning based on the physical lab ***,based on these scans,discrete element R-block and ball models were utilized to construct both the coarse and fine particles within the *** vibro-compaction was employed to regulate the degree of *** results indicate that an increase in vertical pressure,coupled with a zero dilatancy angle,results in a rising stress ratio,indicative of grain *** interlocking exhibits a positive correlation with both the coarse content and the degree of compaction,and varies depending on the shear *** interlocking progresses,the shear band,induced by particle movement,expands and is associated with reduced particle rotation near the shear *** study further reveals a consistent positive correlation between interlocking and the principal orientation angle of strong normal c

关键词： Granular material Interlocking Shear resistance Direct shear Discrete element method Vibro-compaction

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Molecular pathology and protein markers for pancreatic cancer:relevance in staging,in adjuvant therapy,in determination of minimal residual disease,and follow-up

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Hepatobiliary Surgery and Nutrition 2024年第1期13卷 56-70页

作者： Caitlin p.Sok Karunesh polireddy david A.Kooby Department of Surgery Emory University School of MedicineAtlantaGAUSA

The diagnosis and monitoring of disease through the detection of circulating protein biomarkers is a growing field in the practice of *** search for more effective protein biomarkers to aid in the diagnosis and treatment of patients with pancreatic ductal adenocarcinoma(pDAC)remains a valuable area of study,given the aggressive and often occult nature of this *** biopsies are attractive,as they offer a minimally invasive and cost-effective approach when compared to traditional biopsy methods and imaging modalities used for diagnosis and *** antigen(CA)19-9 is currently the most commonly used serum protein biomarker for the diagnosis and monitoring of patients with pDAC,but due to its sensitivity and specificity,its utility remains *** this review,we examine how circulating protein biomarkers are used in the diagnosis,prognostication,and surveillance of *** also highlight protein biomarkers that are currently under investigation that have the potential to enhance our ability to detect early-stage malignancies,predict response to therapy,and monitor for recurrence,but these markers require larger prospective validation studies before they can be widely *** efforts to identify and validate novel biomarkers will be crucial for improving the management and outcomes of patients with this challenging disease.

关键词： Biomarkers pancreatic adenocarcinoma protein

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Corneal and intraocular pressure changes associated to the circadian rhythms:a narrative review

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International Journal of Ophthalmology(English edition) 2024年第10期17卷 1921-1928页

作者： Laura Barberán-Bernardos MiguelÁngel Ariza-Gracia david p piñero Department of Optics Pharmacology and AnatomyUniversity of AlicanteSan Vicente del Raspeig 03690AlicanteSpain ARTORG Center for Biomedical Engineering Research University of BernBern 3008Switzerland Department of Ophthalmology(IMQO-Oftalmar) Vithas Medimar International HospitalAlicante 03016Spain

AIM:To synthesize the current body of research regarding the diurnal variations in intraocular pressure(IOp)and corneal biomechanical and morphological parameters,highlighting their significance in various eye ***:A comprehensive review of studies on the diurnal variations of IOp and corneal parameters was *** findings from various studies were assessed,including the Goldmann applanation tonometry(GAT)and non-contact *** on the variations in central corneal thickness(CCT),corneal curvature,and corneal biomechanics measured by the Ocular Response Analyzer system across different population groups was extracted and ***:In both healthy subjects and those with Fuchs dystrophy,IOp and CCT demonstrate marked diurnal *** remains the gold standard for tonometry,with the highest ***,its measurements are influenced by *** patients and those with pseudoexfoliation showed significant diurnal variations in *** biomechanical parameters,especially corneal hysteresis(CH)and the corneal resistance factor(CRF),largely remain stable throughout the day for most of eye conditions,with some ***,the corneal morphology diurnal variation,particularly curvature,yielded mixed conclusions across ***:Circadian rhythms significantly influence various corneal parameters,most notably IOp and *** studies should emphasize standardized approaches larger sample sizes,and delve deeper into less-explored areas,such as the effects of orthokeratology lenses on diurnal biomechanical shifts.

关键词： circadian rhythms intraocular pressure corneal thickness corneal biomechanics corneal curvature

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Hybrid LES/RANS Simulations of Compressible Flow in a Linear Cascade of Flat Blade profiles

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Journal of Thermal Science 2024年第5期33卷 1839-1850页

作者： Jaromír pRIHODA petr STRAKA david SIMURDA petr SIDLOF Jan LEpICOVSKY Institute of Thermomechanics of the Czech Academy of Sciences Dolejskova 1402/518200 Prague 5Czech Republic Aerospace Research and Test Centre Beranovych 13019905 PragueCzech Republic Technical University of Liberec Faculty of MechatronicsStudentska 246117 Liberec 1Czech Republic

The paper reports on 3D numerical simulations of unsteady compressible airflow in a blade cascade consisting of flat profiles using a hybrid LES/RANS approach including a transition *** a first step towards simulation of blade flutter in turbomachinery,various incidence angle offsets of the middle blade were *** simulations were run for the flow regime characterized by outlet isentropic Mach number M_(is)=0.5and zero *** results of the LES/RANS simulations(pressure and Mach number distributions)were compared to a baseline RANS model,and to experimental data measured in a high-speed wind *** numerical results show that both methods overpredict flow separation taking place at the leading *** this regard,the hybrid LES/RANS method does not provide superior results compared to the traditional RANS ***,the LES/RANS results also capture vortex shedding from the blunt trailing *** frequency of the trailing edge vortex shedding in CFD simulations matches perfectly the spectral peak recorded during wind tunnel measurements.

关键词： numerical simulation blade cascade hybrid LES/RANS

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physically active primary care physicians consult more on physical activity and exercise for patients: A public teaching-hospital study

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Sports Medicine and Health Science 2024年第1期6卷 82-88页

作者： Ann Kee Lee Rosediani Bt Muhamad Vina phei sean Tan Exercise&Sports Science School of Health SciencesHealth CampusUniversiti Sains Malaysia16150Kubang KerianMalaysia Department of Family Medicine School of Medical SciencesHealth CampusUniversiti Sains Malaysia16150Kubang KerianMalaysia

physical activity and exercise(pAE)improve quality of life and reduce the effects of chronic *** care physicians(pCps)play an important role to encourage pAE in *** aim to assess pCps'current pAE consultation practices and their enablers/barriers in daily clinical *** had 64 pCps(age[35.3±4.7]y,47 women)that completed self-administered questionnaires on pAE consultation practices,training,and confidence ***(n=42)also completed the International physical Activity Questionnaire-Short Form to assess their physical activity(pA)*** conducted correlation,one-way analysis of variance and a linear regression to assess the associations between enablers,barriers and pA levels to pAE consultation *** average,pCps consulted on pAE in 49.7%of their daily clinical *** of pCps(70%)strongly agreed that more pAE knowledge were needed to increase consultation *** three barriers related(ppractices were lack of pAE education(r=0.47),patients’preference of pharmaceutical interventions(r=0.45)and lack of continuing education in pAE for pCps(r=0.37).physically active pCps(health-enhancing pA levels,n=6)gave significantly more daily consultations in pAE,73.2%±21.9%,compared to inactive pCps(n=13),37.4%22.8%(p=0.013).In our regression output,pCps who had higher pA levels consulted more on pAE daily(R^(2)=0.38,ppCps require more knowledge on pAE and need be physically active themselves to increase pAE consultation for patients in their daily *** education should consider including more pA and exercise topics that may benefit both physicians and their patients.

关键词： physical activity and exercise primary care physicians Consultations Exercise prescription Medicine

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TRAIL and Celastrol Combinational Treatment Suppresses proliferation, Migration, and Invasion of Human Glioblastoma Cells via Targeting Wnt/β-catenin Signaling pathway

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Chinese Journal of Integrative Medicine 2024年第4期30卷 322-329页

作者： QIN Jing-jing NIU Meng-da CHA Zhe GENG Qing-hua LI Yu-lin REN Chun-guang david p.Molloy YU Hua-rong Research Center of Neuroscience School of Basic Medical SciencesChongqing Medical UniversityChongqing(400016)China Laboratory of Developmental Biology Department of Cell Biology and GeneticsSchool of Basic Medical SciencesChongqing Medical UniversityChongqing(400016)China Department of Biochemistry and Molecular Biology School of Basic Medical SciencesChongqing Medical UniversityChongqing(400016)China

Objective To investigate the mechanistic basis for the anti-proliferation and anti-invasion effect of tumor necrosis factor-related apoptosis-induced ligand(TRAIL)and celastrol combination treatment(TCCT)in glioblastoma *** Cell counting kit-8 was used to detect the effects of different concentrations of celastrol(0-16µmol/L)and TRAIL(0-500 ng/mL)on the cell viability of glioblastoma cells.U87 cells were randomly divided into 4 groups,namely control,TRAIL(TRAIL 100 ng/mL),Cel(celastrol 0.5µmol/L)and TCCT(TRAIL 100 ng/mL+celastrol 0.5µmol/L).Cell proliferation,migration,and invasion were detected by colony formation,wound healing,and Transwell assays,*** reverse transcription polymerase chain reaction and Western blotting were performed to assess the levels of epithelial-mesenchymal transition(EMT)markers(zona occludens,N-cadherin,vimentin,zinc finger E-box-binding homeobox,Slug,and β-catenin).Wnt pathway was activated by lithium chloride(LiCl,20 mol/L)and the mechanism for action of TCCT was *** Celastrol and TRAIL synergistically inhibited the proliferation,migration,invasion,and EMT of U87 cells(pp-regulated the expression of GSK-3β and down-regulated the expression of β-catenin and its associated proteins(ppproteinase(MMp)-*** addition,LiCl,an activator of the Wnt signaling pathway,restored the inhibitory effects of TCCT on the expression of β-catenin and its downstream genes,as well as the migration and invasion of glioblastoma cells(ppppress glioblastoma cell migration,invasion,and EMT,potentially through inhibition of Wnt/β-catenin *** underlies a novel mechanism of action for TCCT as an effective therapy for glioblastoma.

关键词： celastrol Chinese medicine tumor necrosis factor-related apoptosis-induced ligand glioblastoma β-catenin Tripterygium wilfordii

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