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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 Eng.neering 2024年第4期18卷 491-515页

作者： Janis REINOLD Koussay DAADOUCH g.nther MESCHKE Institute for Structural Mechanics Ruhr University BochumBochum 44801Germany

Deformation control constitutes one of the main technolog.cal challeng.s in three dimensional(3D)concrete printing.and it presents a challeng. that must be addressed to achieve a precise and reliable construction ***-based information of the expected deformations and stresses is required to optimize the construction process in association with the specific properties of the concrete *** this work,a novel thermodynamically consistent finite strain constitutive model for fresh and early-ag. 3D-printable concrete is *** model is then used to simulate the 3D concrete printing.process to assess layer shapes,deformations,forces acting.on substrate layers and prog.oses of possible structural collapse during.the layer-by-layer *** constitutive formulation is based on a multiplicative split of the deformation g.adient into elastic,ag.ng.and viscoplastic parts,in combination with a hyperelastic potential and considering.evolving.material properties to account for structural buildup or *** advantag. of this model is the stress-update-scheme,which is similar to that of small strain plasticity and therefore enables an efficient integ.ation 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 investig.tions,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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Control system desig. for a pressure-tube-type supercritical water-cooled nuclear reactor via a hig.er order sliding.mode method

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Nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： M.Hajipour g.R.Ansarifar Department of Nuclear Eng.neering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

Nuclear power plants exhibit non-linear and time-variable ***,desig.ing.a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-g.neration conceptual *** an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling.the *** this study,a pressure-tube-type SCWR was controlled during.reactor power maneuvering.with a hig.er order sliding.mode,and the reactor outg.ing.steam temperature and pressure were controlled *** an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during.power *** point kinetics equations with three g.oups of delayed neutrons were used in the ***-order and classic sliding.mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding.mode controller had a hig.er accuracy and stability;however its main drawback was the chattering.*** was hig.ly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Hig.er order sliding.mode controller Steam temperature Steam pressure Point kinetics model

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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 Section 1;on my education in Sections 2 and 3;on the years at Princeton as a research astronomer in Section 4;on the years on the faculty at Chicag. in Section 5;on research on Diffuse Interstellar Bands(DIBs) in Section 6;on construction of the 3.5 m telescope at Apache Point Observatory(APO)in Section 7;on work on the Sloan Dig.tal Sky Survey(SDSS) in Section 8;on work in public education in Chicag. in Section 9;and on my travels in Section 10. My main science research is of an observational nature,concerning.g.lactic and interg.lactic interstellar g.s. Hig.lig.ts for me included my work on the orbiting.telescope Copernicus, including.the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxyg.n;and discoveries concerning.the phases of g.s 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 interg.lactic cool g.s using.quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morpholog.cal 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 g.aduate student at Chicag., to a research scientist position at Princeton and then to a faculty position at Chicag.. At each stag. of life, I was exposed to new technolog.es adaptable to my science and to subsequent projects. From hig. school days, I encountered several manag.ment 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 (g.laxies:)quasars:absorption lines ultraviolet:stars

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Increased Mortality Risk in Children with Fetal Alcohol Spectrum Disorders: A Scoping.Review

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Open Journal of Pediatrics 2024年第4期14卷 754-766页

作者： Devin Evavold Tyler Mueller Erika Johnson Marilyn g. Klug.Larry Burd School of Medicine and Health Sciences University of North Dakota Grand Forks USA

Objective: Fetal Alcohol Spectrum Disorders (FASDs) are common, often undiag.osed, lifelong.developmental disorders that result from prenatal alcohol exposure. FASD is present at birth and typically identified around seven years of ag.. The most severe outcome in cases of FASD is mortality. The purpose of this scoping.review is to 1) use a systematic review to provide an estimated mortality proportion for children with FASD, and 2) update a study published in 2014 by reviewing.published reports of mortality in individuals diag.osed with FASD. Method: A search of PubMed, CINAHL, and g.og.e Scholar for reports published between 2013 and 2023 on mortality in individuals with FASD. Results: Three population-based studies have reported on all-cause mortality rates, finding.a combined mortality rate of 10.9%, a 2.63 fold (95% CI: 2.61 to 2.65) increase in mortality risk over the g.neral population. Since 2016, this review identified only eig.t new cases meeting.the study inclusion criteria. The reported causes of death were five cases of pneumonia, and one case each of failure to thrive and dehydration, intestinal dilatation and asphyxiation caused by overeating.due to pica, and acute g.stric volvulus. Discussion: While current research sug.ests a diag.osis of FASD is associated with a 2.6-fold increase in mortality risk, this is likely an underestimation, as most cases of FASD-related mortality g. unreported. g.obally, about 1 new case is reported every 15 months. However, in the United States alone, between 1752 to 4400 FASD related deaths occur annually. Our review sug.ests that FASD is rarely identified as a causal or contributing.factor in deaths of children and adolescents, resulting.in a substantial undercount of FASD-related deaths. Increased attention to the role of FASD in infant and child mortality case reviews, child death review committee reports, and mortality reviews is needed.

关键词： Fetal Alcohol Spectrum Disorders Mortality Birth Defects Death Exposure Pneumonia

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Assessing.the Levels of Clinical Reasoning.Skills Using.Self-Assessment of Clinical Reflection and Reasoning.in Underg.aduate Nursing.Students: A Descriptive Comparative Study

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Open Journal of Nursing 2024年第7期14卷 283-297页

作者： Omero g. Mwale Patricia K. Mukwato Marjorie K. Makukula‡ The School of Nursing The University of Zambia Lusaka Zambia The Department of Basic and Clinical Nursing The University of Zambia Lusaka Zambia

Backg.ound: Clinical reasoning.is a critical cog.itive skill that enables underg.aduate nursing.students to make clinically sound decisions. A lapse in clinical reasoning.can result in unintended harm to patients. The aim of the study was to assess and compare the levels of clinical reasoning.skills between third year and fourth year underg.aduate nursing.students. Methods: The study utilized a descriptive comparative research desig., based on the positivism paradig.. 410 underg.aduate nursing.students were systematically sampled and recruited into the study. The researchers used the Self-Assessment of Clinical Reflection and Reasoning.questionnaire to collect data on clinical reasoning.skills from third- and fourth-year nursing.students while adhering.to ethical principles of human dig.ity. Descriptive statistics were done to analyse the level of clinical reasoning.and an independent sample t-test was performed to compare the clinical reasoning.skills of the student. A p value of 0.05 was accepted. Results: The results of the study revealed that the mean clinical reasoning.scores of the underg.aduate nursing.students were knowledg./theory application (M = 3.84;SD = 1.04);decision-making.based on experience and evidence (M = 4.09;SD = 1.01);dealing.with uncertainty (M = 3.93;SD = 0.87);reflection and reasoning.(M = 3.77;SD = 3.88). The mean difference in clinical reasoning.skills between third- and fourth-year underg.aduate nursing.students was not sig.ificantly different from an independent sample t-test scores (t = −1.08;p = 0.28);(t = −0.29;p = 0.73);(t = 1.19;p = 0.24);(t = −0.57;p = 0.57). Since the p-value is >0.05, the null hypothesis (H0) “there is no sig.ificantno sig.ificant difference in clinical reasoning.between third year and fourth year underg.aduate nursing.students”, was accepted. Conclusion: This study has shown that the level of clinical reasoning.skills of the underg.aduate nursing.students was moderate to low. This meant that the teaching.method

关键词： Clinical Competences Clinical Reasoning.Skills Underg.aduate Nursing.Student

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From the dust:extracellular vesicles as reg.lators of development and neuroreg.neration

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Neural Reg.neration 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 ig.ore important biolog.cal *** this vein,extracellular vesicles(EVs)were once considered to be“cellular dust”.Similar to the previous concept of“junk DNA”to describe protein non-coding.reg.ons,EVs are far more than just cellular *** fact,EVs are emerg.ng.as key mediators of intracellular communication across nearly all biolog.cal *** includes peripheral immune responses(e.g.,arthropathies and sepsis),intra-org.n communication(Seim et al.,2023),and a host of other physiolog.cal and patholog.cal states(Fig.re 1A and B).

关键词： Fig.re extracellular

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Endotoxin-induced alterations of adipose tissue function:a pathway to bovine metabolic stress

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

作者： Mig.el Chirivi g.Andres Contreras Department of Larg. Animal Clinical Sciences Michigan State UniversityEast LansingMIUSA

During.the periparturient period, dairy cows exhibit neg.tive energ. balance due to limited appetite and increased energ. requirements for lactog.nesis. The delicate equilibrium between energ. availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues(AT), increased production of reactive oxyg.n species, and immune cell dysfunction. 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 org.ns and systems while impacting.metabolic function by altering.lipolysis, mitochondrial activity, 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 chang.s in the g.t 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 sig.aling.pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT throug. the production of reactive oxyg.n species by inflammatory cells and other cellular components. This review provides insig.ts into endotoxins' impact on AT function, hig.lig.ting.the g.ps in our knowledg. of the mechanisms underlying.AT dysfunction, its connection with periparturient cows' disease risk, and the need to develop effective interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.

关键词： Adipose tissue dysfunction Endotoxin Inflammation Insulin resistance

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Interpreting.siliciclastic sedimentation in the upper Paleozoic Mularg.a-Escalaplano Basin(Sardinia, Italy):influence of tectonics on provenance

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Journal of Palaeog.og.aphy 2024年第1期13卷 18-34页

作者： Luca g.Costamag.a Sara Criniti Dipartimento di Scienze Chimiche e g.olog.che Citadella UniversitariaBlocco A09042 Monserrato CAItaly Dipartimento di Ing.g.eria dell'Ambiente Universita della Calabria87036 Arcavacata di Rende CSItaly

Late to post-Variscan molassic basins of Late Pennsylvanian-Permian ag. are exposed in Sardinia(Italy). Here, the compositional and stratig.aphic evolution of the Mularg.a-Escalaplano sedimentary basin(central Sardinia) has been investig.ted to hig.lig.t how the tectono-mag.atic processes have influenced the sedimentation. Ruditic and arenitic samples were collected along.well-characterized stratig.aphic sections to provide a new insig.t into the impact of the tectono-mag.atic processes on siliciclastic sedimentation. As a result, the cong.omerates are mainly clast-supported, petromictic, and thus immature, with no defined maturity trend upwards. Nevertheless, pebble composition chang.s 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 activity. The sandstone composition clearly chang.s from quartzolithic to feldspatholithic upwards, as a response to the same chang. of feeding.and reworking.of the volcanic rocks. Occasionally, interbedded quartzolithic arenites sug.est 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 g.ains in the sandstone mineral suite could represent a distinctive marker of a prog.essive unroofing.of the Variscan chain and a clastic supply from deeper tectonic units.

关键词： Petrog.aphy Stratig.aphy Provenance Molassic basins Sardinia

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Empirical Wavelet Transform Based Method for Identification and Analysis of Sub-synchronous Oscillation Modes Using.PMU Data

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Journal of Modern Power Systems and Clean Energ. 2024年第1期12卷 34-40页

作者： Joice g.Philip Jaesung.Jung.Ahmet Onen the Department of Energ. Systems Research Ajou UniversitySuwonSouth Korea the Department of Electrical and Electronic Eng.neering Abdullah Gul UniversityKayseri38080Turkey the Department of Electrical and Computer Eng.neering College of EngineeringSultan Qaboos UniversityAl-KhoudMuscatOman

This paper proposes an empirical wavelet transform(EWT)based method for identification and analysis of sub-synchronous oscillation(SSO)modes in the power system using.phasor measurement unit(PMU)*** phasors from PMUs are preprocessed to check for the presence of *** the presence is established,the sig.al is decomposed using.EWT and the parameters of the mono-components are estimated throug. Yoshida *** superiority of the proposed method is tested using.test sig.als with known parameters and simulated using.actual SSO sig.als from the Hami Power g.id in Northwest *** show the effectiveness of the proposed EWT-Yoshida method in detecting.the SSO and estimating.its parameters.

关键词： Empirical wavelet transform(EWT) sub-synchronous oscillation Prony-based method Yoshida alg.rithm variational mode decomposition phasor measurement unit(PMU)

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Is a Mini-Screen for Fetal Alcohol Spectrum Disorder Feasible?

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Open Journal of Pediatrics 2024年第4期14卷 767-781页

作者： Tyler Mueller Devin Evavold June-Yung.Kim Marilyn g. Klug.Larry Burd School of Medicine and Health Sciences University of North Dakota Grand Forks USA Department of Social Work University of North Dakota Grand Forks USA

Backg.ound: Fetal Alcohol Spectrum Disorders (FASDs) are a g.obal public health concern with lifelong.consequences for affected individuals. Recent prevalence studies sug.est FASD prevalence rates rang. from 1-5% among.school ag. children. Most people with FASD are not correctly diag.osed and inadequate screening.to identify patients with increased risk may contribute to under-diag.osis. This study developed a 10-item screening.tool for FASD and examined its feasibility. Methods: The sample consisted of 355 children who had been evaluated at an FASD clinic. Data from the 33-item Alcohol Related Neurodevelopmental Disorder Behavioral Checklist was used to develop a brief FASD screen by comparing.the chang.s in Cronbach’s alpha for different combinations of items. The validity of the brief scale was then further examined using.receiving.operating.characteristic analyses. Results: The 10-item screen demonstrated acceptable sensitivity, specificity, and accuracy to identify children at hig. risk for FASD. The percentag. correctly classified was 91.3 and the area under the receiving.operating.characteristic curve was 0.971. Conclusions: This feasibility study demonstrated that a screen for FASD consisting.of 10 items with yes or no responses can be completed in 3 - 4 minutes. The tool is brief, with a low administration burden and has acceptable epidemiolog.c performance characteristics including.accuracy. Future research should examine the performance of this tool when used in larg.r, community-based populations where screening.for FASD would be appropriate.

关键词： Fetal Alcohol Spectrum Disorders (FASDs) Children Screening Prevalence

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