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First-principles calculation on the electronic structures, phonon dynamics, and electrical conductivities of Pb_(10)(PO_(4))_(6O) and Pb_(9)Cu(PO_(4))_(6O) compounds

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Journal of Materials Science & Technology 2024年第6期173卷 218-224页

作者： l.Y.Hao E.g.Fu State Key laboratory of Nuclear Physics and Technology Department of Technical PhysicsSchool of PhysicsPeking UniversityBeijing 100871China

Superconducting materials with high critical temperature have the potential to revolutionize many fields,including military,electronic communications,and power ***,scientists around the world have been tirelessly working with the ultimate goal of achieving high-temperature *** 2023,a preprint by lee et *** South Korea claimed the discovery of ultra-high-temperature superconductivity with a critical temperature of up to 423 K in Cu-doped lead-apatite(lK-99)(arXiv:2307.12008,arXiv:2307.12037),which caused a worldwide sensation and ***,the electronic structures,phonon dynamics,and electrical conductivities of lK-99 and its parent compound lead-apatite have been calculated using first-principles *** results show that the lead-apatite compound and the lK-99 compound are insulator and half-metal *** flat band characteristic is consistent with previous *** electrical conductivity of the lK-99 compound shows two extreme points,and the electrical conductivity along the C-axis increases significantly after 400 *** phonon dispersion spectra of the compounds were investigated,demonstrating their dynamic instability.

关键词： Superconductivity lK-99 lead-apatite First-principles calculation

Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： l.Iniya B.Sivakumar g.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a Bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

Combustion characteristics of low-quality lignite for different bed material sphericities in a circulating fluidized bed boiler:A numerical study

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Particuology 2024年第7期90卷 364-382页

作者： Barış gürel gülşah Karaca Dolgun Osman İpek Ali Keçebaş Department of Mechanical Engineering Engineering FacultySüleyman Demirel UniversityÇünürIspartaTurkey Department of Energy Systems Engineering Technology FacultyMuğla SıtkıKoçman UniversityKötekliMenteşeMuğlaTurkey

This study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler(CFBB),with a primary focus on the impact of different bed material sphericity ratios(0.5,0.7,and 0.9).Utilizing bed material with a sphericity ratio of 0.9 sourced from theÇan power plant and verified through experimentation,the research reveals several key ***,furnace temperatures tended to rise with higher sphericity ratios,albeit with variations between lignite types,particularly highlighting the complexity of this relationship in the case of glI-Tunçbilek *** levels in the combustion chamber remained consistent across different sphericity ratios,indicating minimal influence on pressure *** combustion efficiency,especially at the bottom of the boiler,was observed at lower sphericity levels(0.5 and 0.7)forÇan lignite,as reflected in CO_(2) mole *** NO_(x) emissions generally decreased with lower sphericity,the sensitivity to sphericity varied by lignite type,with Ilgın lignite showcasing low NO_(x) but high SO_(2) emissions,underscoring the intricate interplay between lignite properties,sphericity,and ***,this study advances our understanding of CFBB combustion dynamics,offering insights valuable for optimizing performance and emissions control,particularly in lignite-based power.

关键词： Circulating fluidized bed boiler Computational particle fluid dynamics method Particle sphericity ratios NO_(x)and SO_(2)emissions Energy production efficiency

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 197-216页

作者： C.g.PAVITHRA B.J.gIREESHA M.l.KEERTHI Department of Pg Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTM) trihybrid nanofluid magnetic field

Mechanical Behavior of Panels Reinforced with Orthogonal Plant Fabrics: Experimental and Numerical Assessment

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Journal of Renewable Materials 2024年第10期12卷 1791-1810页

作者： Martha l.Sánchez g.Capote Universidad Militar Nueva granada Programa de Ingeniería CivilBogotá110111Colombia Facultad de Ciencias Departamento de FísicaUniversidad Nacional de ColombiaBogotá111321Colombia

The construction sector is one of the main sources of pollution,due to high energy consumption and the toxic substances generated during the processing and use of traditional *** production of cement,steel,and other conventional materials impacts both ecosystems and human health,increasing the demand for ecological and biodegradable *** this paper,we analyze the properties of panels made from a combination of plant fibers and castor oil resin,analyzing the viability of their use as construction *** the research,orthogonal fabrics made with waste plant fibers supplied by a company that deals with the manufacture of furniture and craft products were *** fabrics were made with strips of plant fibers of the Calamus rotang,Bambusa vulgaris,Heteropsis flexuosa,and Salix viminalis *** improve their compatibility with the castor oil resin,a cold argon plasma treatment was *** effect of the treatment on the properties of the fibers and the panels was *** density,water absorption capacity,and swelling percentage were ***,compression,static bending,and linear buckling tests were carried *** study found that panels made with treated fiber fabrics exhibited a reduction of approximately 10%in absorption capacity and up to 35%in swelling percentage *** made with Bambusa vulgaris fabrics exhibited the highest strength and stiffness *** models were constructed using commercial finite element *** comparing the numerical results with the experimental ones,differences of less than 15%were seen,demonstrating that the models allow adequately predicting the analyzed *** comparing the values obtained with the characteristic values of oriented strand board,the results suggest that panels made with unconventional materials could replace commercial panels traditionally made with wood-based fibers and particles and other composite materials in several applications in th

关键词： Unconventional materials nonstructural panels plantﬁbers surface treatment physical properties mechanical properties

A multi-sensor appiproach to calving detection

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Information Processing in Agriculture 2024年第1期11卷 45-64页

作者： Anita Z.Chang David l.Swain Mark g.Trotter Institute for Future Farming Systems School of HealthMedicaland Applied SciencesCentral Queensland UniversityRockhamptonQueensland 4700Australia

The advent of remote livestock monitoring systems provides numerous possibilities for improving on-farm productivity,efficiency,and *** potential application for these systems is for the detection of calving *** study describes the integration of data from multiple sensor sources,including accelerometers,global navigation satellite systems(gNsS),an accelerometer-derived rumination algorithm,a walk-over-weigh unit,and a weather station for parturition detection using a support vector machine *** best performing model utilised data from gNsS,the ruminating algorithm,and weather stations to achieve 98.6%accuracy,with 88.5%sensitivity and 100%*** topranking features of this model were primarily gNSS *** study provides an overview as to how various sensor systems could be integrated on-farm to maximise calving detection for improved production and welfare outcomes.

关键词： Accelerometer gNSS gPS Rumination Sensor WOW

Digital Social Connectedness as a lifeline for Older People: Use and Non-use of VinclesBCN During the Pandemic

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International Journal of Disaster Risk Science 2024年第2期15卷 251-264页

作者： Israel Rodríguez‑giralt Daniel lópez‑gómez Roser Beneito‑Montagut CareNet IN3Universitat Oberta de Catalunya08018 BarcelonaSpain School of Social Sciences Cardif UniversityCardif CF103NSWalesUK

This article presents the results of a study that evaluated VinclesBCN during COVID-19. This digital-based public social service aims to prevent loneliness and isolation in +65-year-old adults living in Barcelona. Through service user(N = 12) and professional(N = 6) interviews and a questionnaire with service users(N = 255), we demonstrate the pivotal role of digital connectedness in transforming VinclesBCN into a lifeline during the pandemic. The analysis revealed the importance of sociability, social support, and, especially, entertainment in coping with pandemic fatigue and facilitating social connectivity and support among users. Users engaged in activities such as sharing images, songs, memes, and daily greetings to provide proximity, sociability, and care among users, whether they belonged to preexisting groups or were newly introduced to the platform. It also facilitated the identification of individuals who needed companionship, comfort, or more specialized support. The findings emphasize the significance of entertainment as a resilience-building strategy during times of uncertainty. Despite the positive impact, not all users equally used the platform. Non-use was strongly associated with being a woman, having a low educational level, having preexisting social relationships, less time of enrolment in the platform, as well as a high perception of loneliness, poor self-reported health, and low mood. The article underscores the need for further research into older adults' digital engagement during crises, its role in building resilience, and advocating for inclusive digital interventions that take into account diverse older adults' needs and experiences in crisis contexts.

关键词： Barcelona COVID-19 pandemic Digital social connectedness Entertainment Older adult resilience Public digital service

In vitro engineered models of neurodegenerative diseases

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BIOCEll 2024年第1期48卷 79-96页

作者： ZEHRA gÜl MORÇIMEN ŞEYMA TAŞDEMIR AYlIN ŞENDEMIR Bioengineering Department Graduate School of Natural and Applied SciencesEge UniversityIzmir35040Türkiye Bioengineering Department Faculty of Engineering and Natural ScienceCelal Bayar UniversityManisa45110Türkiye Bioengineering Department Ege UniversityIzmir35040Türkiye Department of Biomedical Technologies Graduate School of Natural and Applied SciencesEge UniversityIzmir35040Türkiye

Neurodegeneration is a catastrophic process that develops progressive damage leading to functional andstructural loss of the cells of the nervous system and is among the biggest unavoidable problems of our *** do not reflect the pathophysiology observed in humans due to distinct differences between the neuralpathways,gene expression patterns,neuronal plasticity,and other disease-related mechanisms in animals *** in vitro cell culture models are also not sufficient for pre-clinical drug testing in reflecting thecomplex pathophysiology of neurodegenerative ***,modern,engineered techniques are applied to developmulticellular,intricate in vitro models and to create the closest microenvironment simulating biological,biochemical,and mechanical characteristics of the in vivo degenerating *** THIS review,the capabilities and shortcomings ofscaffold-based and scaffold-free techniques,organoids,and microfluidic models that best reflect neurodegeneration invitro in the biomimetic framework are discussed.

关键词： Neurodegenerative diseases In vitro models Scaffolds Organoids Microfluidic devices

Prevalence of Helicobacter pylori infection among patients with esophageal carcinoma

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World Journal of gastroenterology 2024年第29期30卷 3479-3487页

作者： Miriam lópez-gómez Maria Morales Rebeca Fuerte Marta Muñoz Pedro-David Delgado-lópez Jorge Francisco gómez-Cerezo Enrique Casado Department of Medical Oncology Precision Oncology LaboratoryInfanta Sofía University HospitalSan Sebastián de los Reyes 28231MadridSpain Department of Medical Oncology Infanta Sofía University HospitalSan Sebastián de los Reyes 28702Spain Department of Internal Medicine Infanta Sofía University HospitalSan Sebastián de los Reyes 28703MadridSpain Department of Pathology Infanta Sofía University HospitalSan Sebastián de los Reyes 28702Spain Department of Neurosurgery Burgos University HospitalBurgos 09006Spain Department of Internal Medicine Infanta Sofía University Hospital and Henares University Hospital Foundation for Biomedical Research and InnovationSan Sebastian de los Reyes 28702MadridSpain Department of Medical Oncology Infanta Sofia University Hospital and Henares University Hospital Foundation for Biomedical Research and InnovationSan Sebastian de los Reyes 28702MadridSpain

BACKgROUND Helicobacter pylori(***)is a widespread microorganism related to gastric adenocarcinoma(AC).In contrast,it has been reported that an inverse association exists between *** infection and esophageal *** mechanisms underlying this supposedly protective effect remain *** To determine the prevalence of *** infection in esophageal carcinoma patients,we performed a retrospective observational study of esophageal tumors diagnosed in our *** We retrospectively reviewed the prevalence of *** infection in a cohort of patients diagnosed with esophageal *** or previous proton pump inhibitor(PPI)usage was also *** A total of 89 patients with esophageal carcinoma(69 males,77.5%),with a mean age of 66 years(range,26-93 years)were *** was the most frequent pathological variant(n=47,52.8%),followed by squamous cell carcinoma(n=37,41.6%).Fourteen ACs(29.8%)originated in the gastroesophageal junction and 33(70.2%)in the esophageal ***,54 patients(60.7%)presented at stages III and *** *** infection occurred only in 4 patients(4.5%),3 with AC(6.3%of all ACs)and 1 with squamous cell carcinoma(2.7%of all squamous cell tumors).All patients with previous *** infection had stage *** one patient had received prior *** eradication therapy,whereas 86(96.6%)had received previous or concomitant PPI *** In our cohort of patients,and after histologic evaluation of paraffin-embedded primary tumors,we found a very low prevalence of previous *** *** also reviewed the medical history of the patients,concluding that the majority had received or were on PPI *** minimal prevalence of *** infection found in this cohort of patients with esophageal carcinoma suggests a protective role.

关键词： Helicobacter pylori Eradication Esophageal tumor Dysbiosis Proton pump inhibitors Carcinogenesis Microbiota Incidence