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Defence Technology（防务技术） 2017年第1期13卷 40-46页

作者： v.r.Arun prakash A.rajadurai Department of Production Technology MITAnna UniversityChennai 600 044India Faculty Department of Production TechnologyMITAnna UniversityChennai 600 044India

In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane treatment on fibre. The composites were fabricated by laying 20, 30 and 40vol% of e-glass fibre into epoxy resin matrix. The e-glass fibre woven mat was surface treated by an amine functional coupling agent 3-Aminopropyletrimethoxysilane(APTMS). The fibres were surface treated by aqueous solution method and thermo assisted to create silinol groups. Similarly for acid treatment H_2SO_4 and base treatment Na OH with 1N concentration was used for surface treating the fibres. Effectiveness of silane treatment on glass fibre was compared by inter laminar shear strength test according to ASTM D *** process with varying diameter drill bit and varying cutting speed was applied to check the composites for their delamination resistance while machining. Maximum improvement of 15%, 12.5% and9%(20, 30 and 40 vol %) on ILSS was achieved for siliconized e-glass fibre reinforced epoxy *** scanning electron microscopy images revealed that no fibre pull out was present on fractured surfaces of composites which contains siliconized e-glass fibre. Similarly better dimensional accuracy was achieved on drilling process for composites contains siliconized e-glass fibre.

关键词： Polymer matrix composites Surface treatment ILSS SEM

Quantifying droplet–solid friction using an atomic force microscope

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Droplet 2024年第2期3卷 105-112页

作者： Xue Qi koh Calvin Thenarianto ville Jokinen Dan Daniel Institute of Materials research and Engineering(IMrE) Agency for ScienceTechnology and Research(A*STAR)SingaporeSingapore Department of Chemistry and Materials Science School of Chemical EngineeringAalto UniversityEspooFinland Division of Physical Sciences and Engineering King Abdullah University of Science and Technology(KAUST)ThuwalSaudi Arabia

Controlling the wetting and spreading of microdroplets is key to technologies such as microfluidics,ink-jet printing,and surface *** angle goniometry is commonly used to characterize surface wetting by droplets,but the technique is ill-suited for high contact angles close to 180°.Here,we attach a micrometric-sized droplet to an atomic force microscope cantilever to directly quantify droplet–solid friction on different surfaces(superhydrophobic and underwater superoleophobic)with sub-nanonewton force *** demonstrate the versatility of our approach by performing friction measurements using different liquids(water and oil droplets)and under different ambient environments(in air and underwater).Finally,we show that underwater superoleophobic surfaces can be qualitatively different from superhydrophobic surfaces:droplet–solid friction is highly sensitive to droplet speeds for the former but not for the latter surface.

关键词： surface underwater latter

MgCo2-D2 and MgCoNi-D2 systems synthesized at high pressures and interaction mechanism during the HDDr processing

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Progress in Natural Science:Materials International 2017年第1期27卷 74-80页

作者： Chubin Wan v.E.Antonov r.v.Denys v.I.Kulakov v.A.Yartys University of Science and Technology Beijing Institute for Energy Technology Institute of Solid State Physics Russian Academy of Sciences HYSTOrSYS AS Norwegian University of Science and Technology

MgCo2and MgNiCo crystallize with hexagonal Laves type intermetallic structures of the C14 type and do not form hydrides at ambient hydrogen pressures. However, applying high hydrogen pressures in the GPa range forces the hydrogen absorption and leads to the formation of multi-phase compositions, which contain approximately 2.5 atoms H per formula unit of MgCo2or MgNiCo and remain thermally stable under normal *** hydrogenation of MgCo2resulted in its decomposition to a ternary Mg2CoD5deuteride and metallic cobalt. Phase-structural transformations accompanying the vacuum desorption of deuterium in the temperature range of 27–500 °C were studied using in situ neutron powder diffraction. The investigation showed a complete recovery of the initial MgCo2intermetallic via a Hydrogenation-Disproportionation-Desorption-recombination process. At 300°C, the Mg2CoD5deuteride first decomposed to elementary Mg and hexagonal Co. At 400°C, a MgCo phase was formed by interaction between Mg and Co. At the highest processing temperature of 500°C, a solid-state interaction of MgCo and Co resulted in the recovery of the initial *** interaction of MgNiCo with deuterium under the synthesis conditions of 2.8 GPa and 200 °C proceeded in a more complex way. A very stable ternary deuteride MgNi2D3was leached away while Co was separated in the form of Mg2CoD5and the remaining nickel formed a solid solution with Co with the approximate composition *** thermal desorption of deuterium from MgCo2D2.5and from MgNiCoD2.5has been studied by Thermal Desorption Spectroscopy with deuterium released into a closed volume. The observed effects nicely correlate with changes in the phase structural composition of the hydrides ***2is a new example of the hydrogen storage alloy, in which a successful HDDr processing results in the reversible formation of the initial intermetallic at much lower temperatures than in the equilibrium phase diagram of the Mg-Co system.

关键词： Intermetallics Hydrogen storage materials Neutron powder diffraction High pressure synthesis Phase-structural transformations Magnesium Cobalt Nickel

role of monovalent co-dopants on the PL emission properties of YAl_3(BO_3)_4:Ce^(3+) phosphor

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Journal of rare Earths 2014年第10期32卷 927-932页

作者： r.Satheesh Kumar v.Ponnusamy v.Sivakumar M.T.Jose Department of Physics Anna UniversityM.I.T. Campus research and Development Laboratory Department of PhysicsSaveetha Engineering College radiological Sefety Division Indira Gandhi Centre for Atomic Research

The cerium （Ce3＋） doped yttrium aluminium borate （YAB） phosphor was synthesized by modified solid state reaction. The phosphor＇s phase purity and its emission properties were studied using powder X-ray diffraction pattern and photoluminescence spectroscopy. The synthesized YAB had rhomobohedral crystal structure. The phosphor had two different excitation and emission spectra. By 325 nm excitation, the phosphor had emission at 373 nm and with 363 nm excitation; the phosphor gave violet-blue emission at 418 nm. The Uv emission of the phosphor originated due to Ce3＋ ions at the yttrium site and violet-blue emission owing to Ce3＋ ions at non-regular sites viz., A13＋ and interstitial sites. The emission intensity of the phosphor was enhanced when monovalent ions （K＋, Na＋, and F） were added as co-dopants. The crucial role of ionic radii of monovalent co-dopants on the emission enhancement of the YAB：Ce3＋ phosphor was reported. Thermogravimetric study showed that the YAB possessed high thermal stability at up to 900 ℃.

关键词： yttrium aluminium borate cerium monovalent codopants ionic radii thermogravimetric analysis rare earths

vanadium-Doped Magnesium Oxide Nanoparticles Formation in Presence of Ionic Liquids and Their Use in Photocatalytic Degradation of Methylene Blue

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Acta Metallurgica Sinica(English Letters) 2016年第3期29卷 253-264页

作者： Harshad r.Patil Z.v.P.Murthy Department of Chemical Engineering S.V.National Institute of Technology r&D Division Hazira Manufacturing DivisionReliance Industries Limited

Magnesium oxide（MgO） is one of the metal oxides having unique properties with numerous potential industrial *** this study,MgO and vanadium-doped MgO nanoparticles were synthesized by sol–gel method in 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF_4] and 1-octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF_4] ionic ***-doped MgO nanoparticles exhibited nanosphere and nanorod morphologies with 40–80 nm in particle size,primarily due to the influence of ionic liquids as demonstrated by high-resolution scanning electron microscopy and transmission electron *** of nanoparticles were also studied by thermal gravimetric analysis,X-ray diffraction and energy-dispersive X-ray *** ability of synthesized nanoparticles was evaluated for methylene blue（MB） in specially designed Uv *** is found to be dependent on doping,and particle characteristics change due to the influence of ionic *** ionic liquid-assisted vanadium-doped MgO nanoparticles showed good reusability under Uv irradiation and MB degradation ability under visible light.

关键词： Ionic liquid vanadium pentoxide Magnesium oxide Sol–gel Photocatalytic activity

Copper doped nickel aluminate: Synthesis, characterisation, optical and colour properties

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Chinese Journal of Chemical Engineering 2019年第10期27卷 2596-2605页

作者： v.Elakkiya r.Abhishekram S.Sumathi Department of Chemistry School of Advanced SciencesVITVellore632014India

Novel environment friendly inorganic nano green pigments,Ni1-xCuxAl2O4(x=0,0.02,0.04,0.06,0.08,0.1)were successfully synthesised by simple,cost effective sol–gel method using citric acid as a gelling *** nano pigments were characterised by powder XrD,FT-Ir,Uv-DrS,SEM–EDX and *** of elements such as Ni,Cu,Al and O for the pigment Ni0.98Cu0.02Al2O4 was authenticated by elemental mapping *** colour parameters were studied using CIE-LAB *** is evident from the DrS measurement that the band gap energy of Ni Al2O4(3.11 ev)has been massively diminished to 2.63 ev when x=0.02,unexpectedly changed the colour of the pigment from cyan to *** x=0.1 the pigment colour has turned into grey and the corresponding band gap condensed into 2.17 *** of mineralisers like NaF,CaF2,NH4H2PO4 and Li2CO3 on the colour of Ni0.98Cu0.02Al2O4 was investigated.

关键词： Nickel aluminate Sol–gel Green pigment Citric acid Chemical resistance

Effect of Process Parameters on Tensile Strength of Friction Stir Welded Cast LM6 Aluminium Alloy Joints

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Journal of Materials Science & Technology 2009年第5期25卷 655-664页

作者： M.Jayaraman r.Sivasubramanian v.Balasubramanian Department of Mechatronics Engineering Kongu Engineering CollegeErodeTamil NaduIndia Department of Mechanical Engineering Coimbatore Institute of TechnologyCoimbatoreTamil NaduIndia Centre for Materials Joining&research(CEMAJOr) Department of Manufacturing EngineeringAnnamalai UniversityAnnamalainagarTamil NaduIndia

This paper reports the effect of friction stir welding （FSW） process parameters on tensile strength of cast LM6 aluminium alloy. Joints were made by using different combinations of tool rotation speed, welding speed and axial force each at four levels. The quality of weld zone was investigated using macrostructure and microstructure analysis. Tensile strength of the joints were evaluated and correlated with the weld zone hardness and microstructure. The joint fabricated using a rotational speed of 900 r/min, a welding speed of 75 mm/min and an axial force of 3 kN showed superior tensile strength compared with other joints. The tensile strength and microhardness of the welded joints for the optimum conditions were 166 MPa and 64.8 Hv respectively.

关键词： LM6 aluminium alloy Friction stir welding Tool rotation speed Welding speed Axial force Tensile strength

Bending sensor based on flexible spin valve

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Chinese Physics B 2023年第5期32卷 655-661页

作者： L I Naumova r S Zavornitsyn M A Milyaev N G Bebenin A Y Pavlova M v Makarova I K Maksimova v v Proglyado A A Zakharov v v Ustinov M.N.Miheev Institute of Metal Physics Ural BranchRussian Academy of SciencesS.Kovalevskoi Street 18Ekaterinburg 620990Russia

Flexible spin valves were prepared by magnetron sputtering on polyimide substrates. The buffer layer that reduces significantly the effect of the polymer substrate on the spin valve microstructure and magnetoresistive properties was revealed. Bending deformation was applied to the microobjects based on the flexible spin valves in parallel to anisotropy axes. It was revealed that during the bend the magnetoresistance changes due to the joint impact of both the change of the magnetic field projection on the film plane and the change of the magnetic properties of the ferromagnetic layers. The obtained dependences have been used in construction of bending sensor, in which the flexible spin valve microstripes were united into the Wheatstone bridge.

关键词： spin valve polymer substrate magnetostriction magnetic anisotropy

Investigation of Cast Copper Structure

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Journal of Harbin Institute of Technology(New Series) 2014年第5期21卷 107-111页

作者： r K Mysik S v Brusnitsyn A v Sulitsin Ural Federal University

In this paper,the results of exploration macrostructure and microstructure of continuous cast copper bars are shown. Quantitative parameters of copper cast bars depending on the speed of continuous casting are rated. It is fixed that independent of speed of casting the macrocrystalline columnar structure consisting of four zones is formed. By means of raster electron microscopy,the microstructure of cast copper is studied. It is determined that the accumulations of eutectic Cu-Cu2O in the form of lines and gas pores by size from 2 to 35 microns at the boundaries grain are observed. With the use of the transmission electron microscope,specific dislocation configuration on cast copper sub-boundary grains is determined. It indicates to high-temperature strain of cupper in the course of cast bar solidification. The important finding can be used for the design technology of copper continuous casting and plastic working of cast bars.

关键词： copper macrostructure microstructure electronic microscopy hardness cast bar continuous casting defects.

Synergistic effect of nano-silica slurries for cementing oil and gas wells

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Petroleum research 2020年第1期5卷 83-91页

作者： r.v.v.ramana Murthy Murthy Chavali Faruq Mohammad Division of Chemistry Department of Sciences and HumanitiesVignan’s Foundation for ScienceTechnology and Research University(Vignan’s University)Vadlamudi 522213 Guntur DistrictAndhra PradeshIndia b PG Department of Chemistry Dharma Appa Rao CollegeNuzvid 521201 Krishna DistrictAndhra PradeshIndia Shree velagapudi ramakrishna Memorial College(SvrMC-PG Studies) NAAC’A’Grade&ISO 9001:2015 Certified(Autonomous)Nagaram 522268 Guntur DistrictAndhra PradeshIndia MCETrC TenaliGuntur 522201 Andhra PradeshIndia Surfactants research Chair King Saud UniversityCollege of ScienceRiyadh 11451 Kingdom of Saudi Arabia

Nanosilica,when combined with cement slurry aids in improving its compressive strength even,reduces the wait-on-cement time for cement *** study focuses on the synergistic effect of nano-silica in oil and gas well cementing.A comparative study is conducted on the performance of cement slurry(conventional 118 pcf(15.8 lbm/gal))with nanosilica and cement slurry without *** cement slurry combined with nano-silica has shown an early compressive strength development in cement slurry at different concentration of silica fume at 10% and 20% by weight of *** study also focuses on other areas for improvement including slurry stability,free fluid reduction,lower fluid loss value,fine rheology,appropriate thickening time and higher ultimate compressive strength *** cement slurry with nano-silica has shown improvement in the compressive strength due to the increased rate of hydration,thus thickening time was within 5hrs.

关键词： Nanosilica Thickening time Compressive strength Ultrasonic cement analyzer