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Analysis of particle dispersion and cavity formation during bulk particle water entry using fully coupled CFD-DEM-VOF approach

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Particuology 2024年第7期90卷 558-580页

作者： Utkan Çalışkan Sanja Mišković Norman b.Keevil institute of Mining Engineering University of British Columbia2329 West MallVancouverBC V6T 1Z4Canada

This paper presents the development and validation of a fully coupled computational fluid dynamics—discrete element method—volume of fluid(CFD-DEM-VOF)model to simulate the complex behavior of particle-laden flows with free *** coupling between the fluid and particle phases is established through the implemented continuity,momentum,and alpha transport *** coupled particle forces such as drag,pressure gradient,dense virtual mass,viscous,and interface forces are also integrated,with drag and dense virtual mass forces being dependent on local *** integrated conservative alpha transport equation ensures phase volume conservation during interactions between particles and ***,we have implemented a trilinear interpolation method designed to operate on unstructured hexahedral *** method has been tested for its ability to properly resolve the coupling effects in the numerical simulations,particularly in cases with a relatively low cell-size *** model is validated through three distinct test cases:single particle water entry,dam break with particles,and water entry of a group of particles *** experimental setup is built to study the dynamics of the water entry of a group of particles,where three key flow features are analyzed:the evolution of average particle velocity,cavity shape,and particle dispersion cloud profiles in *** tests involve four different scenarios,including two different water levels(16.1 and 20.1 cm)and two different particle densities(2650 and 4000 kg/m3).High-speed videometry and particle tracking velocimetry(using imageJ/TrackMate)methods are employed for experimental data *** is demonstrated that numerical results are in excellent agreement with theoretical predictions and experimental *** study highlights the significance of vortices in cavity shaping and particle *** validated CFD-DEM-VOF model constitutes a robust tool for simulating particle-laden flows,cont

关键词： CFD-DEM-VOF Trilinear interpolation Particle-laden flow Free-surface Particle water entry Volume conservation

Pelleting and particle size reduction of corn increase net energy and digestibility of fiber,protein,and fat in corn-soybean meal diets fed to group-housed pigs

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Journal of Animal Science and biotechnology 2024年第4期15卷 1751-1760页

作者： Su A Lee Diego A.Rodriguez Chad b.Paulk Hans H.Stein Department of Animal Sciences University of IllinoisUrbanaIL 61801USA Department of Grain Sciences and industry Kansas State UniversityManhattanKS 66506USA

background Reduction of the particle size of corn increases energy digestibility and concentrations of digestible and metabolizable *** may also reduce particle size of grain,but it is not known if there are interactions between particle size reduction and *** objective of this experiment was to test the hypothesis that particle size reduction and pelleting,separately or in combination,increase N balance,apparent total tract digestibility(ATTD)of fiber and fat,and net energy(NE)in corn-soybean meal diets fed to group-housed *** Six corn-soybean meal-based diets were used in a 3×2 factorial design with 3 particle sizes of corn(i.e.,700,500,or 300μm)and 2 diet forms(i.e.,meal or pelleted).Pigs were allowed ad libitum access to feed and ***-four castrated male pigs(initial weight:29.52 kg;standard diviation:1.40)were allotted to the 6 diets using a 6×6 Latin square design with 6 calorimeter chambers(i.e.,4 pigs/chamber)and 6 *** consumption and CO_(2)and CH_(4)productions were measured during fed and fasting states and fecal and urine samples were *** Regardless of particle size of corn,the ATTD of gross energy(GE),N,and acid-hydrolyzed ether extract(AEE),and the concentration of NE were greater(Pin pelleted diets than in meal *** of diet form,the ATTD of GE,N,and AEE,and the concentration of NE were increased(linear;Pby reducing the particle size of corn,but the increase was greater in meal diets than in pelleted diets(interaction;Pions both pelleting and reduction of corn particle size increased nutrient digestibility and NE,but increases were greater in meal diets than in pelleted diets.

关键词： Corn Digestibility Feed technology Net energy Particle size Pelleting

Markov Chain Modelling of Reliability Analysis and Prediction under Mixed Mode Loading

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 307-314页

作者： SiNGH Salvinder AbDULLAH Shahrum nik MOHAMED nik Abdullah MOHD NOORANi Mohd Salmi Department of Mechanical and Materials Engineering Faculty of Engineering & Built EnvironmentUniversiti Kebangsaan Malaysia Department of Mechanical Engineering Universiti Malaysia Pahang School of Mathematical Sciences Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia

The reliability assessment for an automobile crankshaft provides an important understanding in dealing with the design life of the component in order to eliminate or reduce the likelihood of failure and safety *** failures of the crankshafts are considered as a catastrophic failure that leads towards a severe failure of the engine block and its other connecting *** reliability of an automotive crankshaft under mixed mode loading using the Markov Chain Model is *** Markov Chain is modelled by using a two-state condition to represent the bending and torsion loads that would occur on the *** automotive crankshaft represents a good case study of a component under mixed mode loading due to the rotating bending and torsion *** estimation of the Weibull shape parameter is used to obtain the probability density function,cumulative distribution function,hazard and reliability rate functions,the bathtub curve and the mean time to *** various properties of the shape parameter is used to model the failure characteristic through the bathtub curve is ***,an understanding of the patterns posed by the hazard rate onto the component can be used to improve the design and increase the life cycle based on the reliability and dependability of the *** proposed reliability assessment provides an accurate,efficient,fast and cost effective reliability analysis in contrast to costly and lengthy experimental techniques.

关键词： reliability Weibull Markov Chain mixed mode failure

Protein glycation:a wolf in sweet sheep’s clothing behind neurodegeneration

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Neural Regeneration Research 2024年第5期19卷 975-976页

作者： Ana b.Uceda Francisco Leal-Pérez Miquel Adrover institut Universitari d’investigacióen Ciències de la Salut(iUNiCS) institut d’investigacióSanitària illes balears(idiSba) Departament de Química Universitat de les Illes BalearsCtraPalma de MallorcaSpain

At the beginning of the 16th century,Paracelsus coined the maxim:“the dose makes the poison”.This principle can be applied to all living organisms,including organs and *** brain and its glial and neuronal cells are ... 详细信息

关键词： organs sheep sweet

Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants

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international Journal of Extreme Manufacturing 2024年第1期6卷 353-374页

作者： Amit bandyopadhyay indranath Mitra Sushant Ciliveri Jose D Avila William Dernell Stuart b Goodman Susmita bose W.M.Keck biomedical Materials Research Laboratory School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America Veterinary Clinical Sciences College of Veterinary MedicineWashington State UniversityPullmanWA 99164United States of America Department of Orthopedic Surgery Stanford University Medical CenterRedwood CityCA 94063United States of America

bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. in this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. in vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

关键词： Ti6Al4V load-bearing implants additive manufacturing 3D printing antibacterial performance

Simulation and experimentation of Propeller-Savonius turbine tested underwater surface

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CLEAN ENERGY 2024年第3期8卷 20-33页

作者： Wuryanti, Sri Sasono, Teguh Manunggal, bambang P. Mursanto, Wahyu b. Sugianto Politekn Negeri bandung Politeknik Negeri Bandung Bandung Indonesia Politekn Negeri Padang Dept Mech Engn Padang Indonesia

indonesia's vast maritime territory offers a unique opportunity for harnessing the potential Energy of seawater currents. This study explores the effectiveness of a combined Savonius and propeller-type turbine system. The Savonius turbine, known for its efficiency in capturing ocean currents due to its large sweep area, is combined with a propeller-type turbine to enhance rotational speed and power generation. A novel approach is employed to induce turbulence and optimize energy extraction, first channeling water through the propeller turbine and then into the Savonius turbine. A comprehensive investigation is conducted through simulations and experimental tests within a controlled tunnel environment. The study explores the performance of two-bladed and three-bladed Propeller-Savonius configurations at varying inlet water velocities (0.1, 0.3, 0.6 and 1.0 m/s). The simulation incorporates a turbulence model with 5% intensity and a hydraulic diameter of 0.216 m. Results indicate that the proposed configuration achieves a maximum power output of 2.0293 W with an impressive efficiency of 63.339% in simulation. Concurrently, experimental testing yields a peak efficiency of 61.335% and turbine power of 0.3951 W. The findings demonstrate the feasibility of the combined turbine system and highlight the importance of turbulence in optimizing energy extraction from seawater currents. This research contributes valuable insights into the design and performance of hybrid turbines for harnessing oceanic Energy, emphasizing the potential for sustainable power generation in maritime regions. The methodology and results presented herein offer a foundation for further exploration and refinement of seawater current energy conversion technologies. The study combines a Savonius turbine and a propeller turbine to enhance rotational speed and power generation. CFD simulations and experiments document performance at different water velocities. The findings show that this system is promisi

关键词： hydro-turbine propeller -Savonius renewable energy water WiND TURbiNE PERFORMANCE bLADES CFD RATiO

Ab initio density response and local field factor of warm dense hydrogen

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Matter and Radiation at Extremes 2024年第5期9卷 48-67页

作者： Tobias Dornheim Sebastian Schwalbe Panagiotis Tolias Maximilian P.böhme Zhandos A.Moldabekov Jan Vorberger Center for Advanced Systems Understanding(CASUS) D-02826 GörlitzGermany Helmholtz-Zentrum Dresden-Rossendorf(HZDR) D-01328 DresdenGermany Space and Plasma Physics Royal Institute of Technology(KTH)Stockholm SE-10044Sweden Technische Universität Dresden D-01062 DresdenGermany

We present quasi-exact ab initio path integral Monte Carlo(PiMC)results for the partial static density responses and local field factors of hydrogen in the warm dense matter regime,from solid density conditions to the strongly compressed *** full dynamic treatment of electrons and protons on the same footing allows us to rigorously quantify both electronic and ionic exchange–correlation effects in the system,and to compare the results with those of earlier incomplete models such as the archetypal uniform electron gas or electrons in a fixed ion snapshot potential that do not take into account the interplay between the two *** full electronic density response is highly sensitive to electronic localization around the ions,and our results constitute unambiguous predictions for upcoming X-ray Thomson scattering experiments with hydrogen jets and fusion *** PiMC results are made freely available and can be used directly for a gamut of applications,including inertial confinement fusion calculations and the modeling of dense astrophysical ***,they constitute invaluable benchmark data for approximate but computationally less demanding approaches such as density functional theory or PiMC within the fixed-node approximation.

关键词： local incomplete rigorous

Clinical features of gastroesophageal reflux disease and erosive esophagitis:insights from patients undergoing esophagogastroduodenoscopy in resource-limited Ethiopia

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World Journal of Gastroenterology 2024年第34期30卷 3883-3893页

作者： Firehiwot A Mengistie Abate b Shewaye Abel T Tasamma Zekarias S Ayalew Department of internal Medicine Addis Ababa UniversityAddis Ababa 1176Addis AbabaEthiopia Department of internal Medicine Rheum Rheumatology and Internal Medicine Specialty ClinicAddis Ababa 1000Addis AbabaEthiopia Division of Gastroenterology and Hepatology Department of Internal MedicineAdera Medical and Surgical CenterAddis Ababa 1000Addis AbabaEthiopia

bACKGROUND Gastroesophageal reflux disease(GERD)is a common disease worldwide with varying clinical presentations and risk *** data for Africa is lacking,but an increasing trend is expected due to demographic and epidemiological *** endoscopic studies for general gastrointestinal disorders have shown some patients with erosive esophagitis(EE),no studies in Ethiopia have investigated the clinical characteristics,risk factors,and severity of GERD using esophagogastroduodenoscopy(EGD).AiM To assess the clinical features of GERD in Ethiopian patients who underwent EGD and determine the severity and risk factors of *** We conducted a multicenter,retrospective cross-sectional study of 221 patients diagnosed with GERD and endoscopic findings of EE at Trauma Associated Severe Hemorrhage and Amniotic Membrane Stem Cell between January 2019 and August *** were collected from electronic medical records and phone call *** used descriptive statistics and binary logistic regression analysis with SPSS version 26 to identify the association between variables with a statistical significance set at P valueients was 44.8(±15.9)years,with a male-to-female ratio of 1.6:*** most commonly reported symptom was epigastric pain(80.5%),followed by heartburn(43%).Los Angeles(LA)-A EE was diagnosed in 71.1%of patients,followed by LA-b(14.9%),LA-C(7.7%),and LA-D(5.9%).Multivariate analysis showed that age 50 or above,presence of bleeding,and endoscopic findings of duodenitis/duodenopathy were significantly associated with severe EE(Picture and barrett’s esophagus were observed in 4.5%and 1.36%of patients with EE,*** Most of the patients had milder EE with fewer ***,severe EE was more prevalent in older patients and those with duodenitis/duodenopathy.

关键词： Gastroesophageal reflux disease Erosive esophagitis Hiatal hernia Esophagogastroduodenoscopy Heart burn

Predictive modeling for post operative delirium in elderly

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World Journal of Gastrointestinal Oncology 2024年第9期16卷 3761-3764页

作者： Chris b Lamprecht Abeer Dagra brandon Lucke-Wold Lillian S.Wells Department of Neurosurgery University of FloridaGainevilleFL 32610United States

Delirium,a complex neurocognitive syndrome,frequently emerges following surgery,presenting diverse manifestations and considerable obstacles,especially among the *** editorial delves into the intricate phenomenon of postoperative delirium(POD),shedding light on a study that explores POD in elderly individuals undergoing abdominal malignancy *** study examines pathophysiology and predictive determinants,offering valuable insights into this challenging clinical *** the synthetic minority oversampling technique,a predictive model is developed,incorporating critical risk factors such as comorbidity index,anesthesia grade,and surgical *** is an urgent need for accurate risk factor identification to mitigate POD *** specific to elderly patients with abdominal malignancies,the findings contribute significantly to understanding delirium pathophysiology and *** research is warranted to establish standardized predictive for enhanced generalizability.

关键词： Post-operative delirium Elderly delirium Neurocognitive syndrome Neurotransmitters Abdominal malignancy Predictive model Synthetic minority oversampling technique