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Numerical simulation of three dimensional concrete printing based on a unified fluid and solid mechanics formulation

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Frontiers of Structural and civil Engineering 2024年第4期18卷 491-515页

作者： Janis REiNOLD Koussay DAADOUcH günther MEScHKE institute for Structural Mechanics Ruhr University BochumBochum 44801Germany

Deformation control constitutes one of the main technological challenges in three dimensional(3D)concrete printing,and it presents a challenge that must be addressed to ac.ieve a precise and reliable construc.ion ***-based information of the expected deformations and stresses is required to optimize the construc.ion process in association with the specific properties of the concrete *** this work,a novel thermodynamically consistent finite strain constitutive model for fresh and early-age 3D-printable concrete is *** model is then used to simulate the 3D concrete printing process to assess layer shapes,deformations,forces ac.ing on substrate layers and prognoses of possible structural collapse during the layer-by-layer *** constitutive formulation is based on a multiplicative split of the deformation gradient into elastic,aging and viscoplastic parts,in combination with a hyperelastic potential and considering evolving material properties to account for structural buildup or *** advantage of this model is the stress-update-scheme,which is similar to that of small strain plasticity and therefore enables an efficient integration with existing material *** constitutive model uses the particle finite element method,which serves as the simulation framework,allowing for modeling of the evolving free surfaces during the extrusion *** analyses of three printed layers are used to create deformation plots,which can then be used to control the deformations during 3D concrete *** study offers further investigations,on the structural level,focusing on the potential structural collapse of a 3D printed concrete *** capability of the proposed model to simulate 3D concrete printing processes across the scales—from a few printed layers to the scale of the whole printed structure—in a unified fashion with one constitutive formulation,is demonstrated.

关键词： particle finite element method 3D concrete printing multiplicative split additive manufacturing elastoviscoplasticity

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Rice Husk at a glance:From Agro-industrial to Modern Applications

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Rice science 2024年第1期31卷 14-32页

作者： Masoumeh KORDi Naser FARROKHi Martin i.PEcH-cANUL Asadollah AHMADiKHAH Department of cell&Molecular Biology Faculty of Life Sciences and BiotechnologyShahid Beheshti UniversityTehran ***Iran 1062 Metallurgical industry Avenue Industrial Park Saltillo-Ramos ArizpeRamos ArizpeCoahuila 25900Mexico

Excessive waste produc.ion has led to the concept of a circular bioeconomy to deliver valuable by-products and improve environmental *** annual worldwide rice produc.ion accounts for more than 750 million tons of grain and 150 million tons of *** husk(RH)contains valuable biomaterials with extensive applications in various *** proportions of each component depend primarily on rice genotype,soil chemistry,and c.imatic *** and its derivatives,including ash,biochar,hydrochar,and ac.ivated carbon have been placed foreground of applications in agriculture and other *** the investigation on RH’s compositions,microstructures,and by-products has been done copiously,owing to its unique features,it is still an open-ended area with enormous scope for innovation,research,and ***,we reviewed the latest applications of RH and its derivatives,including fuel and other energy resources,construc.ion materials,pharmacy,medicine,and nanobiotechnology to keep this versatile biomaterial in the spotlight.

关键词： circular bioeconomy rice husk ac.ivated carbon rice husk ash rice husk biochar rice husk hydrochar rice husk application

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A Statistical Study of Magnetic Flux Emergence in Solar Ac.ive Regions Prior to Strongest Flares

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Research in Astronomy and Astrophysics 2024年第4期24卷 147-160页

作者： Alexander S.Kutsenko Valentina i.Abramenko Andrei A.Plotnikov c.imean Astrophysical Observatory p/o NauchnyCrimea298409Russia

Using the data on magnetic field maps and continuum intensity for Solar cycles 23 and 24,we explored 100 ac.ive regions(ARs)that produced M5.0 or stronger *** focus on the presence/absence of the emergence of magnetic flux in these ARs 2-3 days before the strong flare *** found that 29 ARs in the sample emerged monotonically amidst quiet-Sun.A major emergence of a new magnetic flux within a pre-existing AR yielding the formation of a complex flare-produc.ive configuration was observed in another 24 *** 30 ARs,an insignificant(in terms of the total magnetic flux of pre-existing AR)emergence of a new magnetic flux within the pre-existing magnetic configuration was observed;for some of them the emergence resulted in a formation of a configuration with a small δ-sunspot;11 out of 100 ARs exhibited no signatures of magnetic flux emergence during the entire interval of *** six cases the emergence was in progress when the AR appeared on the Eastern limb,so that the classification and timing of emergence were not *** conclude that the recent flux emergence is not a necessary and/or sufficient condition for strong flaring of an *** flux emergence rate of flare-produc.ive ARs analyzed here was compared with that of flare-quiet ARs analyzed in our previous *** revealed that the flare-produc.ive ARs tend to display faster emergence than the flare-quiet ones do.

关键词： Sun:ac.ivity Sun:flares Sun:magnetic fields

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Summary of a Life in Observational Ultraviolet/Optical Astronomy

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Research in Astronomy and Astrophysics 2024年第1期24卷 1-43页

作者： Donald g.York Department of Astronomy and Astrophysics The University of Chicago5801 South Ellis Ave.Chicago 60637ILUSA

i reminisce on my early life in Sec.ion 1;on my education in Sec.ions 2 and 3;on the years at Princeton as a research astronomer in Sec.ion 4;on the years on the faculty at c.icago in Sec.ion 5;on research on Diffuse interstellar Bands(DiBs) in Sec.ion 6;on construc.ion of the 3.5 m telescope at Apache Point Observatory(APO)in Sec.ion 7;on work on the Sloan Digital Sky Survey(SDSS) in Sec.ion 8;on work in public education in c.icago in Sec.ion 9;and on my travels in Sec.ion 10. My main science research is of an observational nature,concerning galac.ic and intergalac.ic.interstellar gas. Highlights for me included my work on the orbiting telescope copernicus, including the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxygen;and discoveries concerning the phases of gas in the local interstellar medium, based on previously unobservable interstellar UV spectral lines. With other instruments and collaborations, i extended interstellar UV studies to the intergalac.ic cool gas using quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morphological character of the source of absorption lines in QSO spectra;and pursued the identification of the unidentified DiBs. For several of these topics, extensive collaborations with many scientists were essential over many years. The conclusions developed slowly, as i moved from being a graduate student at c.icago, to a research scientist position at Princeton and then to a faculty position at c.icago. At each stage of life, i was exposed to new technologies adaptable to my science and to subsequent projects. From high school days, i encountered several management opportunities which were formative. i have been extremely fortunate both in scientific mentors i had and in experimental opportunities i encountered.

关键词： interstellar Medium(iSM) Nebulae (galaxies:)quasars:absorption lines ultraviolet:stars

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Radiative loss of coherence in free electrons:a long-range quantum phenomenon

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Light(Science & Applications) 2024年第2期13卷 294-301页

作者： cruz i.Velasco Valerio Di giulio F.Javier garcía de Abajo icFO-institut de ciencies Fotoniques The Barcelona Institute of Science and Technology08860Castelldefels(Barcelona)Spain icREA-instituciócatalana de Recerca i Estudis Avançats Passeig Lluís Companys 2308010BarcelonaSpain

Quantum physics rules the dynamics of small objects as they interact over microscopic length ***,quantum correlations involving macroscopic distances can be observed between entangled photons as well as in atomic gases and matter waves at low *** long-range nature of the electromagnetic coupling between charged particles and extended objects could also trigger quantum phenomena over large ***,we reveal a manifestation of quantum mechanics that involves macroscopic distances and results in a nearly complete depletion of coherence associated with which-way free-electron interference produced by electron-radiation coupling in the presence of distant extended *** is a ubiquitous effect that we illustrate through a rigorous theoretical analysis of a two-path electron beam interac.ing with a semi-infinite metallic plate and find the inter-path coherence to vanish proportionally to the path separation at zero temperature and exponentially at finite *** investigated regime of large distances originates in the coupling of the electron to radiative modes assisted by diffrac.ion at material structures but without any involvement of material *** the fundamental interest of this macroscopic quantum phenomenon,our results suggest an approach to measuring the vacuum temperature and nondestruc.ively sensing the presence of distant objects.

关键词： temperature quantum macroscopic

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From the dust:extracellular vesicles as regulators of development and neuroregeneration

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Neural Regeneration Research 2024年第5期19卷 933-934页

作者： Leon g.coleman Jr The University of North carolina at chapel Hill School of MedicineDepartment of PharmacologyBowles Center for Alcohol StudiesChapel HillNCUSA

First impressions can have a lasting *** science,this can be especially problematic,because our lack of understanding often causes us to mislabel and thus ignore important biological *** this vein,extracellular vesicles(EVs)were once considered to be“cellular dust”.Similar to the previous concept of“junk DNA”to desc.ibe protein non-coding regions,EVs are far more than just cellular *** fact,EVs are emerging as key mediators of intracellular communication across nearly all biological *** includes peripheral immune responses(e.g.,arthropathies and sepsis),intra-organ communication(Seim et al.,2023),and a host of other physiological and pathological states(Figure 1A and B).

关键词： Figure extracellular

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interpreting siliciclastic sedimentation in the upper Paleozoic Mulargia-Escalaplano Basin(Sardinia, italy):influence of tectonics on provenance

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Journal of Palaeogeography 2024年第1期13卷 18-34页

作者： Luca g.costamagna Sara c.initi Dipartimento di Scienze c.imiche e geologiche Citadella UniversitariaBlocco A09042 Monserrato CAItaly Dipartimento di ingegneria dell'Ambiente Universita della Calabria87036 Arcavacata di Rende CSItaly

Late to post-Variscan molassic basins of Late Pennsylvanian-Permian age are exposed in Sardinia(italy). Here, the compositional and stratigraphic evolution of the Mulargia-Escalaplano sedimentary basin(central Sardinia) has been investigated to highlight how the tectono-magmatic processes have influenced the sedimentation. Ruditic and arenitic samples were collected along well-characterized stratigraphic sec.ions to provide a new insight into the impact of the tectono-magmatic processes on siliciclastic sedimentation. As a result, the conglomerates are mainly clast-supported, petromic.ic, and thus immature, with no defined maturity trend upwards. Nevertheless, pebble composition changes in times from Variscan basement pebble-rich to volcanic rock-rich, as a consequence of the basin widening and the dismantling and reworking of the coeval volcanic ac.ivity. The sandstone composition clearly changes from quartzolithic to feldspatholithic upwards, as a response to the same change of feeding and reworking of the volcanic rocks. Occasionally, interbedded quartzolithic arenites suggest exceptional floods carrying debris from the far borders of the basin. Also, the immature sandstone composition has been interpreted as being controlled by a continuous supply of fresh debris and to a rapid burial rate. in addition, the disappearance of metaradiolarite(lydite AA) Paleozoic grains in the sandstone mineral suite could represent a distinc.ive marker of a progressive unroofing of the Variscan chain and a clastic supply from deeper tectonic units.

关键词： Petrography Stratigraphy Provenance Molassic basins Sardinia

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Endotoxin-induced alterations of adipose tissue func.ion:a pathway to bovine metabolic stress

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1391-1407页

作者： Miguel c.irivi g.Andres contreras Department of Large Animal c.inical Sciences Michigan State UniversityEast LansingMIUSA

During the periparturient period, dairy cows exhibit negative energy balance due to limited appetite and increased energy requirements for lactogenesis. The delicate equilibrium between energy availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues(AT), increased produc.ion of reac.ive oxygen species, and immune cell dysfunc.ion. Metabolic stress, especially in AT, increases the risk for metabolic and inflammatory diseases. Around parturition, cows are also susceptible to endotoxemia. Bacterial-derived toxins cause endotoxemia by promoting inflammatory processes and immune cell infiltration in different organs and systems while impac.ing metabolic func.ion by altering lipolysis, mitochondrial ac.ivity, and insulin sensitivity. in dairy cows, endotoxins enter the bloodstream after overcoming the defense mechanisms of the epithelial barriers, particularly during common periparturient conditions such as mastitis, metritis, and pneumonia, or after abrupt changes in the gut microbiome. in the bovine AT, endotoxins induce a pro-inflammatory response and stimulate lipolysis in AT, leading to the release of free fatty acids into the bloodstream. When excessive and protracted, endotoxin-induced lipolysis can impair adipocyte's insulin signaling pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT through the produc.ion of reac.ive oxygen species by inflammatory cells and other cellular components. This review provides insights into endotoxins' impact on AT func.ion, highlighting the gaps in our knowledge of the mechanisms underlying AT dysfunc.ion, its connec.ion with periparturient cows' disease risk, and the need to develop effec.ive interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.

关键词： Adipose tissue dysfunc.ion Endotoxin inflammation insulin resistance

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Prehospital transdermal glyceryl trinitrate for ultra- acute ischaemic stroke: data from the RigHT- 2 randomised sham- controlled ambulance trial

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Stroke & Vascular Neurology 2024年第1期9卷 38-49,I0035-I0046页

作者： Jason Philip Appleton Lisa J Woodhouse craig S Anderson Sandeep Ankolekar Lesley cala Mark Dixon Timothy J England Kailash Krishnan grant Mair Keith W Muir John Potter christopher i Price Marc Randall Thompson g Robinson christine Roffe Else c Sandset Jeffrey L Saver Angela Shone Aloysius Niroshan Siriwardena Joanna M Wardlaw Nikola Sprigg Philip M Bath Stroke University Hospitals Birmingham NHS Foundation TrustBirminghamUK institute of Applied HealthResearch University of Birmingham College of Medical and Dental SciencesBirminghamUK Stroke Trials Unit Mental Health and Clinical NeurosciencesUniversity of NottinghamNottinghamUK Faculty of Medicine The George Institute for Global HealthSydneyNew South WalesAustralia The george institute c.ina at Peking University Health Science center BeijingChina Neurology Royal Prince Alfred HospitalSydney Health PartnersSydneyNew South WalesAustralia Department of Neurology King's College Hospital NHS Foundation TrustLondonUK Faculty of Health and Medical Sciences University of Western AustraliaCrawleyWestern AustraliaAustralia East Midlands Ambulance Service NHS Trust NottinghamUK Stroke Queen's Medical CentreNottingham University Hospitals NHS TrustNottinghamUK centre for c.inical Brain Sciences Dementia Research InstituteUniveristy of EdinburghEdinburghUK institute of Neurology and Psychology University of GlasgowGlasgowUK Bob champion Research and Education Building University of East AngliaNorwichUK institute of Neuroscience Newcastle UniversityNewcastle upon TyneUK Department of Neurology Leeds Teaching Hospitals NHS TrustLeedsUK Department of cardiovascular Sciences and NiHR Leicester Biomedical Research centre University of LeicesterLeicesterUK Stroke Research in Stoke Institute for Science and Technology in MedicineKeele UniversityStoke-on TrentUK Department of Neurology Oslo University HospitalOsloNorway Research and Development Norwegian Air Ambulance FoundationOsloNorway Department of Neurology and comprehensive Stroke center David Geffen School of MedicineUCLALos AngelesCaliforniaUSA Research and graduate Services University of NottinghamNottinghamUK community and Health Research Unit University of LincolnLincolnUK

Background The effect of transdermal glyceryl trinitrate(gTN,a nitrovasodilator)on c.inical outcome when administered before hospital admission in suspected stroke patients is ***,we assess the safety and efficacy of gTN in the prespecified subgroup of patients who had an ischaemic stroke within the Rapid intervention with glyceryl trinitrate in Hypertensive stroke Trial-2(RigHT-2).Methods RigHT-2 was an ambulance-based multicentre sham-controlled blinded-endpoint study with patients randomised within 4hours of *** primary outcome was a shift in scores on the modified Rankin scale(mRS)at day *** outcomes included death;a global analysis(Wei-Lac.in test)containing Barthel index,EuroQol-5D,mRS,telephone interview for cognitive status-modified and Zung depression scale;and neuroimaging-determined‘brain frailty’*** were reported as n(%),mean(SD),median[iQR],adjusted common OR(acOR),mean difference or Mann-Whitney difference(MWD)with 95%*** 597 of 1149(52%)patients had a final diagnosis of ischaemic stroke;age 75(12)years,premorbid mRS>2107(18%),glasgow coma Scale 14(2)and time from onset to randomisation 67[45,108]***‘brain frailty’was common:median score 2[2,3](range 0–3).At day 90,gTN did not influence the primary outcome(acOR for increased disability 1.15,95%ci 0.85 to 1.54),death or global analysis(MWD 0.00,95%ci-0.10 to 0.09).in subgroup analyses,there were non-significant interac.ions suggesting gTN may be associated with more death and dependency in participants randomised within 1hour of symptom onset and in those with more severe *** in patients who had an ischaemic stroke,ultra-acute administration of transdermal gTN in the ambulance did not improve c.inical outcomes in a population with more c.inical and radiological frailty than seen in previous in-hospital *** iS ALREADY KNOWN ON THiS TOPic⇒Transdermal glyceryl trinitrate(gTN)was associat-ed with less death and dependency in those w

关键词： glasgow nitrate random

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continuous ward monitoring and intensive postoperative management

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c.inese Medical Journal 2024年第6期137卷 631-632页

作者： Kai Li Jiayi Wang Daniel i.Sessler Department of Anesthesiology China-Japan Union HospitalJilin UniversityChangchunJilin 130031China Outcomes Research consortium ClevelandOhio 44195USA Department of Anesthesiology Shanghai Ninth People’s HospitalShanghai JiaoTong University School of MedicineShanghai 201999China Department of Outcomes Research Cleveland ClinicClevelandOhio 44195USA

When patients having major surgery reach the post-anaesthesia care unit,families naturally assume that they have survived the most dangerous part of the perioperative *** assumption is *** in the 30 days after surgery is 140 times higher than intraoperative mortality.^([1,2])in fact,if the month after surgery were considered a disease,it would be the world’s third leading cause of death.^([3])

关键词： assume dangerous wrong

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