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Particuology 2024年第11期94卷 211-228页

作者： Cairen miranda j.hn Palmore j.. Department of Mechanical Engineering Virginia TechBlacksburg24060VAUSA Department of Mechanical Engineering University of WashingtonSeattle98195WAUSA

The present research focuses on improving the prediction of rotating particle *** particle-surface collision models do not accurately predict the particle rebound when taking rotation into *** data,such as the studies by Gorham and Kharaz(2000),Buck,Tang,Heinrich,Deen and Kuipers(2017),and Dong and Moys(2006)show that the Tsuj.,Oshima and Morikawa(1985)model is inaccurate due to the incorrect tangential coefficient of restitution ***,Kuipers,Mohd Salleh,Stein,and Seville(2001)introduced a similar model to the work by Tsuj. et al.(1985)which includes a tangential coefficient of restitution but is only in two dimensions and does not consider out of plane *** work re-derives the particle collision model from the impulse equations for binary collisions in 3D while considering rotating *** derived equations in this work compares well to experimental particle-surface impact *** implications of this model are seen by investigating erosion due to particle collision in a simple pipe *** is shown that Tsuj. et al.(1985)over predicts the *** small differences in particle traj.ctories between the present model and the Tsuj. et al.(1985)model will grow in complex flows with multiple close range particle impacts leading to inaccurate erosion predictions which will negatively impact the design of turbomachinery and pneumatic pipes.

关键词： Particle collisions CFD Rotation Three dimensional

Unsteady Non-Uniform Flow of Molten Metals in Rectangular Open Channels

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World j.urnal of Engineering and Technology 2022年第3期10卷 593-604页

作者： Miguel A. Barron j.an reyes Dulce Y. miranda Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

In the metallurgical industries, it is very important to characterize the flow of molten metals in open channels given that they are transported through these devices to different plant sections. However, unlike the flow of water which has been studied since ancient times, the flow of molten metals in open channels has received little attention. The unsteady non-uniform flow of blast furnace molten pig iron in a rectangular open channel is analyzed in this work by numerical solution of the Saint-Venant equations. The influence of mesh size on the convergence of molten metal height is studied to determine the proper mesh and time step sizes. A sinusoidal inflow pulse is imposed at the entrance of the channel in order to analyze the propagation of the resulting wave. The influence of the angle of inclination of the channel and the roughness coefficient of the walls on the amplitude and the dynamic behavior of the height of the molten metal are analyzed. Phase portraits of the channel state variables are constructed and interpreted. Numerical simulations show that as the angle of inclination of the channel increases, the amplitude of the formed wave decreases. From 10 degrees onwards, the peak of the wave descends even below the initial height. On the other hand, the roughness coefficient affects the molten pig iron height profiles in an inverse way than the angle of inclination. The amplitude of the formed wave increases as the roughness coefficient increases.

关键词： Molten Metals Flow Non-Uniform Flow Open Channels Pig Iron Transport Saint-Venant Equations Sinusoidal Pulse Unsteady Flow

Non-Darcy Flow in Molding Sands

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Open j.urnal of Applied Sciences 2024年第4期14卷 976-982页

作者： Miguel A. Barron-Meza j.an reyes-miranda Daniel Flores-Sanchez Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Ciudad de Mexico Mexico

Darcy’s law is widely used to describe the flow in porous media in which there is a linear relationship between fluid velocity and pressure gradient. However, it has been found that for high numbers of Reynolds this law ceases to be valid. In this work, the Ergun equation is employed to consider the non-linearity of air velocity with the pressure gradient in casting sands. The contribution of non-linearity to the total flow in terms of a variable defined as a non-Darcy flow fraction is numerically quantified. In addition, the influence of the shape factor of the sand grains on the non-linear flow fraction is analyzed. It is found that for values of the Reynolds number less or equal than 1, the contribution of non-linearity for spherical particles is around 1.15%.

关键词： Darcy’s Law Molding Sands Non-Darcy Flow Reynolds Number Shape Factor

Using music to reduce anxiety among older adults in the emergency department:a randomized pilot study

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j.urnal of Integrative Medicine 2017年第6期15卷 450-455页

作者： Laura Belland Laura Rivera-reyes Ula Hwang center for family medicine newyork-presbyterian/columbia university medical centerNew YorkNY 10032USA department of emergency medicine icahn school of medicine at mount sinaiNew YorkNY 10029USA geriatric research education and clinical centerjames j.peters vamcNew YorkNY 10029USA

BACKGROUND： An emergency department （ED） visit may be distressing and anxiety-provoking for older adults （age 〉 65 years）. No studies have specifically evaluated the effect of music listening on anxiety in older adults in the ED. OBj.CTIVE： The obj.ctive of this pilot study was to evaluate the effect of music listening on anxiety levels in older ED patients. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： This was a randomized pilot study in the geriatric ED of an urban academic tertiary medical center. This was a sample of English-speaking adults （age 〉 65 years） who were not deaf （n = 35）. Subj.cts consented to participate and were randomized to receive up to 60 min of music listening with routine care, while the control group received routine care with no music. Subj.cts in the music treatment group received headphones and an electronic tablet with pre-downloaded music, and were allowed to choose from 5 selections. MAIN OUTCOME MEASURES： The primary outcome was change in anxiety levels, measured by the state- trait anxiety inventory （STAI）, at enrollment and 1 h later. RESULTS： A total of 35 participants were enrolled： 74% were female, 40% were white, and 40% were black; of these, 32 subj.cts completed the study protocol. When comparing control （n = 18） against intervention subj.cts （n = 17）, there were no significant differences in enrollment STAI scores （43.00 ± 15.00 vs. 40.30± 12.80, P = 0.57）. STAI scores 1 hour after enrollment （after the music intervention） were significantly reduced in the intervention subj.cts compared to the control subj.cts （with reduction of 10.00± 12.29 vs. 1.88 ± 7.97, P = 0.03）. CONCLUSION： These pilot results suggest that music listening may be an effective tool for reducing anxiety among older adults in the ED.

关键词： music anxiety emergency department randomized controlled trial

Effect of successive sprays on liquid distribution in fluidized beds

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Particuology 2021年第1期19卷 17-24页

作者： Cedric Briens Liliana Pardo reyes Franco Berruti j.nnifer McMillan Institute for Chemicals and Fuels from Alternative Resources Western University22312 Wonderland Rd.IldertonONN0M 2A0Canada Edmonton Research Centre Syncrude Canada Ltd942117th AveEdmontonABT6N 1H4 Canada

In processes such as Fluid Coking^(™),agglomerate formation should be minimized since it reduces the yield of valuable products,and degrades operability because of the fouling of *** experimental model,consisting of an aqueous solution of gum arabic with a dye,has been successfully developed to simulate the formation of agglomerates in the Fluid Coking^(™)process,where bitumen is sprayed into a fluidized bed of coke particles The particles wetted by a spray could be predicted by assuming that all the particles in the wake of bubbles formed from the tip of the spray j.t have been wetted by the inj.cted *** transfer of liquid from particles wetted with the spray to dry bed particles was relatively ineffective,as the number of wet particles increased by only 50%.With successive liquid inj.ctions,the proportion of the liquid trapped in agglomerates increases in latter inj.ctions:large agglomerates from earlier inj.ctions accumulate above the grid and are carried by gas bubbles into the spray j.t cavity,where they seed fresh agglomerates.

关键词： Fluidized bed Liquid inj.ction Agglomerate formation Fluid Coker

Hairless canary seeds (Phalaris canariensis L.) as a potential source of antioxidant, antihypertensive, antidiabetic, and antiobesity biopeptides

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Food Production, Processing and Nutrition 2021年第1期3卷 80-91页

作者： U.C.Urbizo-reyes j.E.Aguilar-Toalá A.M.Liceaga Protein Chemistry and Bioactive Peptides Laboratory Department of Food SciencePurdue University745 Agriculture Mall DriveWest LafayetteIN 47907USA

Rising consumer concerns with synthetic drugs to treat non-communicable diseases(NCDs)have promoted a shift towards using natural biological active constituents that offer similar health *** canary seed(Phalaris canariensis L)is an emerging crop traditionally used in Mexico to treat *** liberated during simulated digestion of canary seed protein are believed to be responsible for their biological activity;however,no studies have shown the effect of controlled protein hydrolysis using commercial proteases on canary seed protein’s biological ***,this study aimed to explore the in vitro antihypertensive,antidiabetic,and anti-obesity activity of canary seed peptides derived from proteolysis with Alcalase®.Protein fractions were primarily composed of prolamins(54.07±1.8%),glutelins(32.19±3.18%),globulins(5.97±0.52%)and albumins(5.97±0.52%).The<3 kDa and 3–10 kDa peptide fractions showed the highest inhibition capacity(p<0.05)towards angiotensin-converting enzyme(IC50=0.028–0.032 mg/mL)lipase(IC50=2.15–2.27 mg/mL),α-glucosidase(IC50=0.82–1.15 mg/mL),and dipeptidyl-peptidase-IV(IC50=1.27–1.60 mg/mL).Additionally,these peptide fractions showed high antioxidant activity against DPPH(134.22–150.66μmol TE/mg)and ABTS(520.92–813.33μmol TE/mg).These results provide an insight into the potential development of functional foods using commercial enzymatic hydrolysis of canary seed proteins for treating hypertension,type-2 diabetes,and obesity.

关键词： Canary seeds Bioactive peptides Anti-obesity activity Antihypertensive activity Antidiabetic activity

A test method for evaluating the thermal environment of underground coal mine refuge alternatives

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International j.urnal of Mining Science and Technology 2019年第3期29卷 343-355页

作者： D.S.Yantek L.Yan N.W.Damiano M.A.reyes j.R.Srednicki CDC NIOSH

Since 2009,the Mine Safety and Health Administration(MSHA)has required mines to install refuge alternatives(RAs)in underground coal *** of the biggest concerns with occupied RAs is the possible severity of the resulting thermal *** 30 CFR 7.504,the maximum allowable apparent temperature(AT)for an occupied RA is specified as 35℃(95°F).Manufacturers must conduct heat/humidity tests to demonstrate that their RAs meet the 35℃(95°F)AT *** these tests,heat input devices are used to input the metabolic heat of actual miners.A wide variety of test methods,sensors,and heat input devices could be used when conducting such *** 2012,the National Institute for Occupational Safety and Health(NIOSH)has conducted over thirty 96-hour heat/humidity tests on four different *** paper discusses the test equipment and procedures used during these *** information is useful for RA manufacturers conducting RA heat/humidity tests,for other researchers investigating RA heat/humidity buildup,and for those who need to assess the thermal environment of any confined space where people may be trapped or are seeking refuge.

关键词： Refuge chamber Refuge alternative Confined space Thermal environment Test method Temperature

BaTiO_(3)solid solutions co-doped with Gd^(3+)and Eu^(3+):Synthesis,structural evolution and dielectric properties

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j.urnal of Rare Earths 2024年第10期42卷 1920-1926页

作者： R.Martínez-López M.Pérez-Labra j.A.Romero-Serrano F.R.Barrientos-Hernández M.reyes-Pérez M.I.Valenzuela-Carrillo G.Urbano-reyes V.E.reyes-Cruz G.I.Dávila-Pulido Academic Area of Earth Sciences and Materials Autonomous University of Hidalgo StateRoad Pachuca-Tulancingo Km 4.5 Mineral de La Reforma.Hidalgo42184Mexico Metallurgy and Materials Department ESIQIE-IPNUPALMZacatencoCiudad de Mexico07738Mexico Autonomous University of Coahuila Boulevard Adolfo López Mateos S/nNueva RositaCoahuila26800Mexico

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO_(3)solid solutions codoped with rare earth elements(Gd^(3+)and Eu^(3+))prepared using the solid-state reaction method are *** pure precursor powders of BaCl_3,TiO_(2),Gd_(2)O_(3),and Eu_(2)O_(3)were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 MPa and sintered at 1300℃in air atmosphere for 6 h to obtain Ba_(1-3x)Gd_(2x)Ti_(1-3x)Eu_(4x)O_(3)(x=0,0.0015,0.01 and0.1).X-ray diffraction(XRD)and Rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO_(3)for the samples with x=0,0.0015 and 0.01,as well as a consistent increment in the lattice parameters caused by the *** solubility limit of Gd^(3+)and Eu^(3+)in the BaTiO_(3)structure is reached for the sample with x>0.01,and the orthorhombic Eu_2TiO_(5)and monoclinic BaTi_(2)O_(5)secondary phases were *** Raman results show the characteristic peaks of ferroelectric tetragonal BaTiO_(3)around 716 cm^(-1)(LO of A1 symmetry),515 cm^(-1)(TO of A1 symmetry),and 305 cm^(-1)(B1).The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and Eu homogeneously distributed in the BaTiO_(3)*** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO_(3) Doping Gadolinium Europium Synthesis Rare earths

Catalytic performance of zinc-supported copper and nickel catalysts in the glycerol hydrogenolysis

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j.urnal of Energy Chemistry 2020年第3期29卷 185-194页

作者： R.j.Chimentao B.C.miranda D.Ruiz F.Gispert-Guirado F.Medina j.Llorca j.B.O.Santos Physical Chemistry Department Faculty of Chemical SciencesUniversity of ConcepcionCasilla 160-CConcepcionChile Chemical Engineering School Universidad de Costa Ric1San Jose 2060Costa Rica Scientific Resources Service Universitat Rovira i VirgiliTarragona 43007Spain Department of Chemical Engineering Universitat Rovira i VirgiliTarragona 43007Spain Department of Chemical Engineering Barcelona Research Center in Multiscale Science and EngineeringInstitute of Energy TechnologiesUniversitat Politècnica de Cataluny1EEBE08019 Barcelon1Spain Department of Chemical Engineering Universidade Federal de Sao Carlos(UFSCAR)Sao CarlosBrazil

Gas-phase catalytic conversion of glycerol to value added chemicals was investigated over zinc-supported copper and nickel *** addition of aluminum in the support was also investigated in glycerol conversion and the results indicate an increase in the acidity and adsorption capacity for both copper and nickel *** and XRD analysis revealed Ni Zn alloy formation in the Ni/ZnO *** XRD patterns of the prepared Zn Al mixed oxide catalysts show the presence of Gahanite phase(ZnAl2O4).In addition,H2 chemisorption and TPR results suggest a strong metal-support interactions(SMSI)effect between Ni and Zn O *** supports Zn O and ZnAl(Zn/Al=0.5)were investigated in the glycerol conversion and they did not present *** supported on ZnO and ZnAl mixed oxide(Zn/Al=0.5)was active towards hydroxyacetone *** was active in the hydrogenolysis of glycerol both for C–C and C–O bonds cleavage of glycerol producing *** metal-support interactions(SMSI)between Ni and ZnO has a remarkable suppression effect on the methanation activity during the glycerol conversion.

关键词： Glycerol Hydrogenolysis Dehydration Hydroxyacetone Copper Nickel Catalyst

NiTi laser textured implants with improved in vivo osseointegration:An experimental study in rats

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j.urnal of Materials Science & Technology 2022年第19期114卷 120-130页

作者： M.M.Costa A.miranda F.Bartolomeu O.Carvalho S.Matos G.miranda F.S.Silva Center for MicroElectroMechanical Systems(CMEMS-UMinho) University of MinhoCampus de AzurémGuimarães 4800-058Portugal Life and Health Sciences Research Institute(ICVS) School of MedicineUniversity of MinhoCampus de GualtarBraga 4710-057Portugal ICVS/3B’s-PT Government Associate Laboratory Braga/GuimarãesPortugal Center for Innovation and Research in Oral Sciences(CIROS) Faculty of MedicineUniversity of CoimbraFMUCPortugal CICECO Aveiro Institute of MaterialsDepartment of Materials and Ceramic EngineeringUniversity of AveiroAveiro 3810-193Portugal

Laser surface texturing is a versatile approach for manufacturing implants with suitable surfaces for *** work explores the use of laser to fabricate NiTi textured implants,testing two dif-ferent groove-based *** performance was evaluated in vivo through implantation in Sprague Dawley rats’femur,being then analyzed after 4 and 12 weeks of ***-out experiments and histological characterization allowed to assess bone-implant bond and osseointegration and to compare the laser textured solutions with non-textured *** showed that,at 4 weeks of implantation,mainly immature woven bone was present whilst at 12 weeks a more mature bone had ***-sidering the largest implantation time(12 weeks),results showed extraction forces considerably higher for textured implants(G2 and G3).Moreover,when comparing G2 and G3,it was found that G2(having the highest textured surface area)displayed the maximum extraction force among all groups,with an increase of 212%when compared to non-textured implants(G1).These results prove that the design and manufacturing technology are effective to promote an im-proved bone-implant bond,aiming the development of orthopedic implants.

关键词： NiTi Laser surface texturing In vivo studies Osseointegration Implants