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High-temperature deformation behaviour of duplex stainless steel with hard boronised layer

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Journal of Iron and Steel research International 2021年第2期28卷 244-253页

作者： N.m.Sultan I.Jauhari r.Saidan m.f.m.Sabri Department of mechanical Engineering Faculty of EngineeringUniversity MalayaKuala Lumpur 50603Malaysia

In order to understand the high-temperature deformation behaviour of alloy having hard surface layer,thermo-mechanically treated duplex stainless steel(DSS)is boronised for 0.75-6 h at 1223 K and subsequently deformed under compression mode at the same temperature under strain rate condition of 1×10^(-3),2×10^(-4) and 6×10^(-5) s^(-1) until strain of *** substrate microstructure is almost isotropic with grain size after boronising with layer thickness between 1.61 and 2.74μm.X-ray diffraction results confirm the formation of boride on DSS *** surface hardness of DSS increases from 387 to 1000-2400 HV after *** boronised layer with thickness of 20-40μm is formed at DSS *** results show that the flow stress of the deformation increases with the strain rate and boronising *** the boronised samples,the flow stress range is between 5 and 89 *** determine the actual effect of the boronised layer on the flow stress,the results are also compared with those from un-boronised samples having similar *** results suggest that at a constant grain size,even with the hardest layer,the effect of hard surface layer on the flow stress almost could be negligible when the deformation rate is slow,but at faster deformation rate,even in the layer with the least hardness,the flow stress shows a significant *** is also observed that the hard boride surface disintegration could be avoided at a sufficiently low deformation flow stress that could be attributed to superplasticity.

关键词： High-temperature deformation Superplasticity Duplex stainless steel Hard boride layer Surface integrity Grain size effect Strain rate effect

Phase modification and dielectric properties of a cullet–paper ash–kaolin clay-based ceramic

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International Journal of minerals,metallurgy and materials 2018年第3期25卷 350-356页

作者： K.A.Samah m.r.Sahar m.Yusop m.f.Omar Advance Optical material research Group Department of Physics Faculty of Science Universiti Teknologi Malaysia

Novel ceramics from waste material made of(x) paper ash–(80-x) cullet–20 kaolin clay(10 wt% ≤ x ≤ 30 wt%) were successfully synthesized using a conventional solid-state reaction technique. Energy-dispersive X-ray analysis confirmed the presence of Si, Ca, Al, and fe in the waste material for preparing these ceramics. The influence of the cullet content on the phase structures and the dielectric properties of these ceramics were systematically investigated. The impedance spectra were verified in the range from 1 Hz to 10 mHz at room temperature. The phase of the ceramics was found to primarily consist of wollastonite(CaSiO_3), along with minor phases of γ-dicalcium silicate(Ca_2SiO_4) and quartz(SiO_2). The sample with a cullet content of 55 wt% possessed the optimum wollastonite structure and exhibited good dielectric properties. An increase of the cullet content beyond 55 wt% resulted in a structural change from wollastonite to dicalcium silicate, a decrease in dielectric constant, and an increase in dielectric loss. All experimental results suggested that these novel ceramics from waste are applicable for electronic devices.

关键词： ceramics cullet glass paper ash wollastonite structural properties dielectric properties

Nonlinear vibration analysis of fractional viscoelastic Euler–Bernoulli nanobeams based on the surface stress theory

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Acta mechanica Solida Sinica 2017年第4期30卷 416-424页

作者： m.faraji Oskouie r.Ansari f.Sadeghi Department of mechanical Engineering University of Guilan

The nonlinear vibrations of viscoelastic Euler-Bernoulli nanobeams are studied using the fractional calculus and the Gurtin-murdoch theory. Employing Hamilton＇s principle, the governing equation considering surface effects is derived. The fractional integro-partial differential governing equation is first converted into a fractional-ordinary differential equation in the time domain using the Galerkin scheme. Thereafter, the set of nonlinear fractional time-dependent equations expressed in a state-space form is solved using the predictorcorrector method. finally, the effects of initial displacement, fractional derivative order, viscoelasticity coefficient, surface parameters and thickness-to-length ratio on the nonlinear time response of simply-supported and clamped-free silicon viscoelastic nanobeams are investigated.

关键词： fractional calculus Viscoelastic nanobeam Nonlinear vibrations

Imidazolium-based ionic liquids as additives to preserve the Enhanced Green fluorescent Protein fluorescent activity

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Green Chemical Engineering 2021年第4期2卷 412-422页

作者： Nathalia V.Veríssimo Carolina f.Saponi Timothy m.ryan Tamar L.Greaves Jorge f.B.pereira Department of Engineering of Bioprocesses and Biotechnology School of Pharmaceutical SciencesSao Paulo State University(UNESP)Rodovia Araraquara-Jaú/Km 0114800-903AraraquaraSPBrazil School of Science College of ScienceEngineering and HealthRMIT University124 La Trobe StreetMelbourneVIC 3000Australia School of Pharmaceutical Sciences Sao Paulo University(USP)Av.Prof.Lineu Prestesno.580B1605508-000Cidade de UniversitariaSao PauloSPBrazil Australian Synchrotron 800 Blackburn RoadClaytonVIC 3168Australia Univ Coimbra CIEPQPFDepartment of Chemical EngineeringRua Sílvio LimaPolo II–Pinhal de Marrocos3030-790 CoimbraPortugal

fluorescent Proteins(fP)can be applied as biomarkers and biosensors in the industrial and medical fields,but their large-scale use,especially for new industrial applications,is limited due to their low ***,the discovery of additives capable of preserving the activity of fP at room temperature and under stress conditions can help to expand and facilitate their commercial *** this goal,we evaluated the application of 1-alkyl-3-methylimidazolium chloride-based([C_(n)mim]Cl)ionic liquids(ILs)as additives to preserve the activity of Enhanced Green fluorescent Protein(EGfP)at different storage times and under unfavorable ***[C_(n)mim]Cl solutions(at 0.100 mol L^(-1))were able to preserve EGfP fluorescence for longer than the phosphatesaline buffer(PBS)and NaCl solutions,increasing its fluorescence manifestation from 1 to 3 months.[C_(n)mim]Cl with shorter to medium cationic alkyl chains were the most effective in preserving EGfP fluorescence.[C_(n)mim]Cl also protected EGfP activity in the presence of the surfactant SDS,the acid guanidine hydrochloride,and H_(2)O_(2).Therefore,[C_(n)mim]Cl can be added to aqueous solutions to preserve EGfP fluorescence activity at room temperature for longer storage times and to reduce the negative impact of denaturing agents on ***,there is a massive potential for the application of ILs as additives to preserve fP in the long-term without refrigeration and under unfavorable conditions,and this is fundamental to enable expansion of fP in industrial and commercial applications.

关键词： Green fluorescent Protein Protein stability fluorescence Ionic liquids Preservatives

magnetically actuated glaucoma drainage devicefor regulating intraocular pressure afterimplantation

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microsystems & Nanoengineering 2023年第4期9卷 91-105页

作者： Inês C.f.pereira ralph J.S.van mechelen Hans m.Wyss Leonard Pinchuk Henny J.m.Beckers Jaap m.J.den Toonder microsystems Department of Mechanical EngineeringEindhoven University of Technology5600MB EindhovenThe Netherlands Institute for Complex molecular Systems(ICmS) Eindhoven University of Technology5600MB EindhovenThe Netherlands University Eye Clinic maastricht Maastricht University Medical Centre+(MUMC+)6202AZ MaastrichtThe Netherlands Innfocus Inc.a Santen CompanyMiamiFlorida 33186USA Ophthalmic Biophysics Center Bascom Palmer Eye InstituteUniversity of Miami Miller School of MedicineMiamiFlorida 33136USA

The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in theeye can reduce IOP and thus stop disease progression. However, most devices currently used in clinical practice arepassive and do not allow for postsurgical IOP control, which may result in serious complications such as hypotony (i.e.,excessively low IOP). To enable noninvasive IOP control, we demonstrate a novel, miniature glaucoma implant that willenable the repeated adjustment of the hydrodynamic resistance after implantation. This is achieved by integrating amagnetic microvalve containing a micropencil-shaped plug that is moved using an external magnet, thereby openingor closing fluidic channels. The microplug is made from biocompatible poly(styrene-block-isobutylene-block-styrene)(SIBS) containing iron microparticles. The complete implant consists of an SIBS drainage tube and a housing elementcontaining the microvalve and fabricated with hot embossing using femtosecond laser-machined glass molds. Usingin vitro and ex vivo microfluidic experiments, we demonstrate that when the microvalve is closed, it can providesufficient hydrodynamic resistance to overcome hypotony. Valve function is repeatable and stable over time. Due to itssmall size, our implant is a promising, safe, easy-to-implant, minimally invasive glaucoma surgery device.

关键词： enable implantation overcome

Synthesis and functionalization of carbon xerogels to be used as supports for fuel cell catalysts

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Journal of Energy Chemistry 2013年第2期22卷 195-201页

作者： Jos L. figueiredo manuel f. r. pereira Laboratory of Catalysis and materials Associate Laboratory LSRE/LCM Faculdade de Engenharia Universidade do Porto Rua Dr. Roberto Frias 4200-465 Porto Portugal

The synthesis and properties of carbon xerogels are briefly described in this mini-review, emphasizing the methods used for tuning their surface chemistry and textural properties in order to design efficient electrocatalysts for fuel cells. In particular, the role played by the surface functional groups in determining the loading, dispersion, oxidation state and stability of the metal phases is addressed.

关键词： carbon xerogels fuel cells electrocatalysts surface chemistry catalyst supports

Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola m.Johannessen Tor I.Olaussen Nansen Scientific Society BergenNorway Nansen Environmental and remote Sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. In general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic minimum ice Climate

Insights from an academic endeavor into central nervous system drug discovery

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Neural regeneration research 2025年第6期20卷 1717-1718页

作者： Lieve van Veggel An m.Voets Tim Vanmierlo rudy Schreiber BIOmED Biomedical research Institute Faculty of Medicine and Life SciencesHasselt UniversityHasseltBelgium Department of Psychiatry and Neuropsychology Division of Translational NeuroscienceEuropean Graduate School of NeuroscienceSchool for Mental Health and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands Section of Psychopharmacology Neuropsychology and PsychopharmacologyFaculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands University mS Center(UmSC) Hasselt-PeltBelgium

Historically,"big pharma"did most central nervous system drug discovery r&D ***,in modern times their"management reductionism"resulted in disappointing pipelines and pharma resided to(late)development,regulatory approval,and marketing(Thong,2015).This had significant consequences for financing and executing research,resulting in a larger role for funding by governments and patient-organizations and a shift of research to academia(mazzucato,2013).

关键词： academic approval consequences

Neurocircuit regeneration by extracellular matrix reprogramming

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Neural regeneration research 2025年第8期20卷 2300-2301页

作者： Shengzhang Su Ian N.Levasseur Kimberly m.Alonge Department of medicinal Chemistry University of WashingtonSeattleWAUSA Department of Chemistry University of WashingtonSeattleWAUSA Department of medicine University of Washington Medicine Diabetes InstituteSeattleWAUSA

The brain's extracellular matrix(ECm),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functioning(Soles et al.,2023).Synthesized by neural and glial cells,the brain's ECm regulates a myriad of homeostatic cellular processes,including neuronal plasticity and firing(miyata et al.,2012),cation buffering(moraws ki et al.,2015),and glia-neuron interactions(Anderson et al.,2016).Considering the diversity of functions,dynamic remodeling of the brain's ECm indicates that this understudied medium is an active participant in both normal physiology and neurological diseases.

关键词： matrix programming