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Flow Regimes in Bubble Columns with and without Internals: A Review

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Fluid Dynamics & Materials Processing 2024年第2期20卷 239-256页

作者： Ayat n.Mahmood Amer A.Abdulrahman Laith S.Sabri Abbas J.Sultan hasan Shakir Majdi Muthanna h.Al-Dahhan Department of Chemical Engineering University of Technology-IraqBaghdadIraq Chemical and Petroleum Industries Engineering Department Al-Mustaqbal University CollegeBabylonIraq Department of Chemical and Biochemical Engineering Missouri University of Science and TechnologyRollaUSA

hydrodynamics characterization in terms ofﬂow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related *** review presents recent studies on the typicalﬂow regimes established in bubble *** effort is also provided to introduce relevant deﬁnitions pertaining to thisﬁeld,namely,that of“void fraction”and related(local,chordal,cross-sectional and volumetric)*** studies involving different parameters that affect design and operating conditions are also discussed in *** the second part of the review,the attention is shifted to cases with internals of various types(perfo-rated plates,bafﬂes,vibrating helical springs,mixers,and heat exchanger tubes)immersed in the bubble *** is shown that the presence of these elements has a limited inﬂuence on the global column ***,they can make the homogeneousﬂow regime more stable in terms of transition gas velocity and transi-tion holdup *** last section is used to highlight gaps which have not beenﬁlled yet and future directions of investigation.

关键词： hydrodynamics ﬂow regime bubble column heat-exchanging internals

wettability,reactivity,and interface structure in Mg/ni system

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Journal of Magnesium and Alloys 2024年第2期12卷 659-672页

作者： S.Terlicka n.Sobczak Ł.Maj P.Darłak J.J.Sobczak Institute of Metallurgy and Materials Science Polish Academy of Sciences25 Reymonta Str.KrakowPoland Faculty of Foundry Engineering AGH University23 Reymonta Str.KrakowPoland

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure ni *** comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact heating(Ch)*** high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;Ch:715℃for 300 s)using Ar+5 wt%h_(2) *** the sessile drop tests,images of the Mg/ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate *** and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified *** was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the ni substrate(an average contact angleθnwed by fast spreading and good wetting over the ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.In contrast,a different wetting behavior was observed for the Ch procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test ***,in both cases,the deep craters formed in the ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-ni alloys suggest a strong dissolution of ni in liquid Mg and apparent values of the final contact angles measured for the Mg/ni system.

关键词： Magnesium-based alloys Sessile drop tests Capillary purification procedure wettability Reactivity Contact angle

Phanerozoic co-evolution of O2-CO2 and ocean habitability

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national Science Review 2024年第6期11卷 18-21页

作者： Zunli Lu Rosalind E.M.Rickaby Jonathan L.Payne Ashley n.Prow Department of Earth & Environmental Sciences Syracuse University Department of Earth Sciences University of Oxford Department of Earth and Planetary Sciences Stanford University

Atmospheric carbon dioxide and oxygen concentrations are partially linked via the geological cycle of organic carbon （Fig. 1A–C; e.g. CO2+h2O■Ch2O+O2）. The history of these two biologically active components, controls on their concentrations, and implications for the complexity of the biosphere and habitability of Earth have been hotly debated, but are generally considered independently.

关键词： CO2-COnCEnTRATInG MEChAnISM OXYGEn EVOLUTIOn AnOXIA

Direct microwave leaching conditions of rare earth elements in fluorescent wastes

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Journal of Rare Earths 2024年第6期42卷 1165-1174,I0007页

作者： A.Bilen B.Birol M.n.Saridede S.S.Kaplan M.S.Sonmez Department of Metallurgical and Materials Engineering Yildiz Technical UniversityIstanbulTurkey Department of Chemical Engineering and Materials Science Stevens Institute of TechnologyNew JereyUSA Department of Metallurgical and Materials Engineering Istanbul Technical UniversityIstanbulTurkey

The luminescent phosphor powder in the fluorescent lamp constitutes 2%of the lamp’s *** can be mentioned that fluorescent wastes are a crucial raw material to produce rare earth *** the present study,microwave leaching process was conducted to dissolve rare earth elements yttrium(Y),europium(Eu),and remaining rare earth elements(REEs)present in the phosphor powder of the fluorescent *** the yields were *** the microwave leaching process,the effects of the temperature(80-160℃),acid type(hydrochloric acid(hCl),nitric acid(hnO_(3)),sulphuric acid(h_(2)SO_(4))),acid concentration(0.5-6 mol/L),solid to liquid ratio(0.1:10-0.5:10)and reaction time(5-90 min)parameters on leaching efficiencies of varying rare earth elements and calcium were *** highest yield was obtained in the direct microwave leaching of fluorescent waste with the experimental conditions of 6 mol/L hCl,160℃,0.1:10 solid-to-liquid ratio(S:L),and 90 *** energy calculations were made,and kinetic models of the reactions were obtained,and it is observed that Y and Eu dissolution is diffusion-controlled,on the other hand,lanthanum(La),cerium(Ce),and terbium(Tb)were examined to be chemical reaction ***,calcium(Ca)and gadolinium(Gd)seem coherent with the mixed ***,mathematical models of all experimental studies are created with the response surface Box-Behnken method and the correlation coefficients of all the models are over 90%.

关键词： Rare earth elements(REEs) Direct microwave leaching Fluorescent waste Kinetic models Response surface method

Sodium nitroprusside as a signal molecule for up-regulating membrane characteristics,antioxidant defense system to improve flax productivity under water stress

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Oil Crop Science 2024年第3期9卷 160-169页

作者： n.M.Al-Ashkar B.A.Bakry h.M.S.El-Bassiouny M.M.S.Abdallah M.S.Sadak Botany Department Agricultural and Biological Research InstituteNational Research Centre33 El Bohouth Street P.O.12622DokkiGizaEgypt Field Crops Research Department Agricultural and Biological Research InstituteNational Research Centre33 El Bohouth Street P.O.12622DokkiGizaEgypt

water stress is a critical environmental adversity that significantly impacts the growth,development,and yield of flax *** this study,flax seeds were cultivated under different water irrigation requirements(wIR)(100%,75%,and 50%)to investigate the effects of exogenously supplied nitric oxide(nO)donor sodium nitroprusside(SnP)as foliar treatments at concentrations of 0.0 mmol/L,0.5 mmol/L,1.0 mmol/L,and 2.0 mmol/*** stress led to a significant decrease in plant growth,photosynthetic pigments,yield components such as oil and total carbohydrate *** also resulted in an increase in leaf h2O2 production,lipid peroxidation levels and activities of enzymatic antioxidants including polyphenol oxidase,superoxide dismutase,and nitrate reductase ***,foliar application of SnP improved photosynthetic pigments and antioxidant defense system which mitigated the negative impact of water stress on growth and yield productivity by reducing oxidative damage caused by reactive oxygen species *** use of SnP also decreased h_(2)O_(2) accumulation levels,lipid peroxidation levels,and improved membrane *** treatment at concentration of 2 mmol/L showed superior results compared to other concentrations with extremely significant increases observed in yield characteristics such as oil content,total carbohydrate percentages,and unsaturated fatty acids to saturated fatty acids ratio.

关键词： Flax Fatty acid Sodium nitroprusside Antioxidant enzymes Yield

A new hydrophobic deep eutectic solvent composed of menthol and tris(2-ethylhexyl) phosphate for solvent bar microextraction of parabens from biological fluids

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Emerging Contaminants 2024年第2期10卷 135-145页

作者： nabil n.AL-hashimi husam Abed Alfattah Khaleel I.Assaf Asma A.Fakhoury Saja h.hamed Amjad h.El-Sheikh Khairi M.Fahelelbom The hashemite University Faculty of Pharmaceutical SciencesDepartment of Pharmaceutical ChemistryP.O.Box 330127Zarqa13133Jordan The hashemite University Faculty of ScienceDepartment of ChemistryP.O.Box 150459Zarqa13115Jordan Al-Balqa Applied University Faculty of ScienceDepartment of Chemistry19117 Al-SaltJordan The hashemite University Faculty of Pharmaceutical SciencesDepartment of Pharmaceutics and Pharmaceutical TechnologyP.O.Box 330127Zarqa13133Jordan Al Ain University College of PharmacyDepartment of Pharmaceutical SciencesP.O.Box 64141Al AinAl AinUnited Arab Emirates

Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and *** the legitimate concerns relating to their potential to disrupt multiple endocrine functions,it becomes imperative to prioritize the development of innovative bioanalytical techniques for effectively monitoring their presence in biological *** this study,an efficient solvent bar microextraction(SBME)was established,utilizing new hydrophobic deep eutectic solvents(DEs)to determine methylparaben and propylparaben in urine and plasma *** DEs comprising menthol and tris(2-ethylhexyl)phosphate(M-TEhP)at various molar ratios were synthesized for the first time to enhance the extraction capacity and promote the eco-friendliness of the DE used as an extraction ***-transform infrared(FT-IR)and proton nuclear magnetic resonance(1h nMR)spectroscopies were employed to confirm and investigate the properties of the successful synthesis(M-TEhP)DE at a molar ratio of 1:*** synthesized DE exhibits low microbial toxicity and can be considered an eco-friendly solvent for ***,quantum-chemical calculations were utilized to predict synthesized DE's structure and interaction energy with selected *** influential operational factors of DE-SBME on the extraction efficiency(EE%)of both parabens were evaluated using response surface methodology based on central composite design,and a total of 30 extraction tests were conducted to determine the optimal *** optimized DE-SBME,in combination with hPLC-DAD,exhibited low detection limits(0.54–0.91μg L^(−1)),excellent linearity(R^(2)≥0.9993),precise results(RSDs≤7.6%),satisfactory recoveries(92–97%)and negligible matrix ***,it had remarkable effectiveness and applicability in determining selected parabens in real urine and plasma samples.

关键词： hydrophobic deep eutectic solvent Solvent bar microextraction Parabens Response surface methodology and central composite design hPLC-DAD Urine and plasma

A detailed comparison of the composition of(RE)-Ba-Cu-O-Ag bulk superconductors

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Superconductivity 2024年第1期9卷 87-94页

作者： J.V.J.Congreve Y.Shi A.R.Dennis h.Druiff n.C.Tutt D.A.Cardwell J.h.Durrell Department of Engineering University of CambridgeCambridgeUK

The homogeneity of the microstructure and composition are critical in determining the properties of rare earthbarium‐cuprate,single grain bulk superconductors[(RE)BCO].The magnitude of the trapped magnetic field achieveable in these technologically important materials,in particular,is influenced heavily by the size and distribution of(RE)_(2)BaCuO_(x)(RE‐211)flux pinning inclusions in the bulk microstructure,whereas the size and distribution of silver agglomerates present within the bulk superconducting matrix correlate directly with improved mechanical *** careful engineering,these materials have significant potential for application in range of devices related to energy storage,medicine,electro‐magnetic machinery and microelectronic *** of(RE)BCO bulk superconductors typically involves heating a powder compact above its peritectic decomposition temperature followed by slow cooling to facilitate the growth of a single ***(RE)BCO composition has a different peritectic temperature and growth rate,which,therefore,necessitates different requirements in the heating *** fabrication temperature and growth rate,for example,may have an effect on the RE‐211 and silver distribution,which may,in turn,affect the superconducting properties of the resulting single *** this work we compare the distributions of silver and RE‐211 in the single grain microstructures of YBCOAg,GdBCO‐Ag,EuBCO‐Ag and SmBCO‐Ag bulk superconductors using optical microscopy,scanning electron microscopy and energy dispersive X‐ray *** observe that the distributions are very similar along both the a/b‐axis and c‐axis of these *** suggests that factors other than the maximum temperature used to achieve peritectic decomposition and the rate of single grain growth are particularly influential in determining the properties of the as‐processed samples in the top seeded melt growth *** observation demonstrates there is freedom to us

关键词： YBCO‐Ag GdBCO‐Ag SmBCO‐Ag EuBCO‐Ag Composition Bulk superconductor

Optimal design of the fillet weld fastening the wind turbine column

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China welding 2024年第3期33卷 39-43页

作者： Imre Timár István w.Árpád Mechanical Engineering Department Faculty of EngineeringUniversity of PannoniaVeszprem H-8200Hungary Mechanical Engineering Department Faculty of EngineeringUniversity of DebrecenDebrecen H-4032Hungary

This paper deals with the optimal design of the fillet weld of wind turbine column subjected to bending *** the premise of determined the force acting on the column,in order to further optimize the fillet weld,the minimum volume of corner seam was determined in the case of non-linear design *** constraints relate to the maximal stresses and fatigue of welding seam.A numerical solution to this problem is given by genetic optimization *** optimisation calculation result indicated that the active condition(constraint)was the stress from the static *** and meaningful information is provided for the engineering field.

关键词： fillet weld optimal design genetic algorithm static and dynamic load

Coke behavior with h_(2)O in a hydrogen-enriched blast furnace:A review

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 959-976页

作者： Feng Zhou Daosheng Peng Kejiang Li Alberto n.Conejo haotian Liao Zixin Xiong Dongtao Li Jianliang Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Chemical Engineering The University of QueenslandSt LuciaQLD 4072Australia Baosteel Central Research Institute(R&D Center of wuhan Iron&Steel Co. Ltd.)Wuhan 430080China Shougang Research Institute of Technology Shougang Group Corporation Ltd.Beijing 100043China Beijing Key Laboratory of Green Recyclable Process for Iron and Steel Production Technology Beijing 100043China

hydrogen-enriched blast furnace ironmaking has become an essential route to reduce CO_(2)emissions in the ironmaking ***,hydrogen-enriched reduction produces large amounts of h_(2)O,which places new demands on coke quality in a blast *** a hydrogen-rich blast furnace,the presence of h_(2)O promotes the solution loss *** result improves the reactivity of coke,which is 20%-30%higher in a pure h_(2)O atmosphere than in a pure CO_(2)*** activation energy range is 110-300 kJ/mol between coke and CO_(2)and 80-170 kJ/mol between coke and h_(2)***_(2)and h_(2)O are shown to have different effects on coke degradation *** review provides a comprehensive overview of the effect of h_(2)O on the structure and properties of *** exploring the interactions between h_(2)O and coke,several unresolved issues in the field requiring further research were *** review aims to provide valuable insights into coke behavior in hydrogen-rich environments and promote the further development of hydrogen-rich blast furnace ironmaking processes.

关键词： hydrogen ironmaking coke behavior blast furnace gasification microstructure kinetics