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MODIFICATION OF SODIUM SALT OF PARTIALLY CARBOXYMETHYLATED TAMARIND kERNEL POWDER THROUGH GRAFTING WITH ACRYLONITRILE: SYNTHESIS, CHARACTERIZATION AND SWELLING BEHAVIOR

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Chinese Journal of Polymer Science 2013年第12期31卷 1670-1684页

作者： J.H.Trivedi J.R.Jivani k.H.Patel H.C.Trivedi P.G.Dept.of Chemistry Sardar Patel UniversityVallabh Vidyanagar Amneal Phamaceuticals

A graft copolymer of polyacrylonitrile （PAN） with sodium salt of partially carboxymethylated tamarind kernel powder （Na-PCMTkP, DS ^-= 0.15） was synthesized by using ceric ammonium nitrate （CAN） as a redox initiator in an aqueous medium. The optimum reaction conditions for affording maximum percentage of grafting were established by successively varying reaction conditions such as concentrations of nitric acid, CAN, monomer （AN） as well as reaction time, temperature and amount of substrate. The influence of these reaction conditions on the grafting yields was discussed. The kinetic scheme of free radical graft copolymerization was proposed and the experimental results were found to agree very well with the proposed kinetic scheme. The graft copolymer （Na-PCMTkP-g-PAN, percentage of grafting G = 413.76% and percentage of grafting efficiency GE = 96.48%） sample synthesized under the established optimized reaction conditions was hydrolyzed by 0.7 mol-L l NaOH solution at 90-95 ℃ to yield the superabsorbent hydrogel, H-Na-PCMTkP-g-PAN. The swelling behavior of the hydrogel was studied by carrying out its absorbency measurements in low conductivity water, 0.15 mol·L^-1 salt （NaCl, CaCl2 and AlCl3） solutions and simulated urine （SU） solution at different timings. FTIR, TGA and SEM techniques were used to characterize the products.

关键词： Sodium salt of partially carboxymethylated tamarind kernel powder Acrylonitrile Graft copolymerization Superabsorbent hydrogels Swelling behavior.

Effect of baffles on performance of fluid catalytic cracking riser

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Particuology 2018年第3期16卷 18-30页

作者： Milinkumar T. Shah Vishnu k. Pareek Geoffrey M. Evans Ranjeet P. Utikar Department of Chemical Engineering Curtin University Western Australia Australia Department of Chemical Engineering University of Newcastle New South Wales Australia

Increasing demand of automobile fuel and a need to process heavier crude oil makes it imperative to find improvements to the design of existing fluid catalytic cracking （FCC） units. Several modifications to the design of the riser section of FCC units have been suggested in previous studies including： improved feed nozzle designs, multiple nozzle configurations, internal baffles, and novel two-stage-riser systems. In this study, we investigate the effects of baffles on the performance of FCC risers using computational fluid dynamics simulations. In this study, predictions from a basis model （without baffles） are compared with those from four different configurations including：（i） 5-cm baffles at 5-m spacing, （ii） 7.5-cm baffles at 5- m spacing, （iii） 10-cm baffles with 5-m spacing, （iv） lO-cm baffles at 2.5-m spacing, and （v） lO-cm baffles at 1-m spacing. The baffles force the catalyst away from wails toward the center of the riser, enhancing the radial dispersion of the catalyst and the heat transfer inside the riser. The use of longer baffles and smaller spacings further increases the dispersion, yielding more homogeneous radial profiles. The changes in the radial dispersion result in variations in the conversion, yields, and pressure drops. The baffles increase conversion of vacuum gas oil （VGO） and the yield of gasoline. However, the simulations showed that longer baffles and a larger number of baffles did not always give a higher yield or higher conversion. Among the simulated configurations, the 5-cm baffles at 5-m spacing gave the highest conversion of VGO, whereas the 10-cm baffles at 1 -m spacing resulted in the highest yield of the gasoline. Thus, rational optimization of baffle configurations is required to achieve optimal performance.

关键词： Fluid catalytic cracking Riser Baffles Computational fluid dynamics

Synthesis of SWNTs over nanoporous Co-Mo/MgO and using as a catalyst support for selective hydrogenation of syngas to hydrocarbon

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Journal of Natural Gas Chemistry 2010年第5期19卷 548-551页

作者： A.M.Rashidi A.karimi H.R.Bozorgzadeh k.kashefi M.Zare Nanotechnology Research Center Research Institute of petroleum industry (RIPI)West Blvd.Azadi Sport ComplexP.O.Box: 14665-1998TehranIran

Single-wall carbon nanotubes （SWNTs） with high surface area were synthesized over nanoporous Co-Mo/MgO by a chemical vapor deposition （CVD） method. The SWNTs were used as catalyst support for selective hydrogenation of syngas to hydrocarbons. Here an extensive study of Fischer-Tropsch synthesis （FTS） on CNT-supported cobalt catalysts with different amounts of cobalt loading up to 40 wt% is reported. The catalysts were characterized by different methods including N2 adsorption-desorption, X-ray diffraction, hydrogen chemisorption, inductively coupled plasma （ICP） and temperature-programmed reduction. Enhancement of the reducibility of Co3O4 to CoO, CoO to Co° and small cobalt oxide particles, dispersion of the cobalt, and activity and selectivity of FTS were investigated and compared with a conventional support. The CNT supported catalysts achieve a high dispersion and high loading of the active metal, cobalt in particular, so that the bulk formation of cobalt metal, which tends to occur in conventional support, can be avoided. The results showed that the specific activity of CNT supported catalysts increase significantly （there is a two fold increase in CO Conversion per gram of the active metal） with respect to the conventional supported catalyst.

关键词： CNT SWNTs Fiscber-Tropsch cobalt reducibility activity C5+ selectivity

Effect of alloying elements on mechanical properties in Cu-15%Cr in-situ composites

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中国有色金属学会会刊：英文版 2004年第2期14卷 284-290页

作者： H.G.Suzuki J.Ma k.Mihara S.Sakai S.Sun Japan Society for Promotion of Science Department of Materials Science and EngineeringFurukawa Electric COFurukawa Electric CONational Institute for Materials Science 4-1-8 Hon-machi Kawaguchi332-0012 JapanDepartment of Materials Science and EngineeringTsinghua UniversityBeijing 100084 China Tsinghua UniversityBeijing 100084China LTDNikko 321-0014JapanLTDNikko 321-0014JapanTsukuba 305-0047Japan

The effects of alloying elements on the mechanical properties as well as electrical conductivity in Cu-15%Cr(mass fraction) in-situ composites were systematically studied and high strength and high electrical conductive Cu base in-situ composites have been developed. The best combination is the addition of 0.1% to 0.2% Zr, Ti, or Sn in Cu-15%Cr in-situ composite, thermomechanical treatment to refine the microstructure and optimizing the precipitation of second phase. The strength is controlled by high density of dislocations in the Cu matrix, the lamellar spacing of the second phase, and the fine Cr precipitates. The aging treatment to reduce solute atoms has a beneficial effect on the increase of electrical conductivity. The addition of Zr, or Ti of about 0.15% to 0.2% promotes the precipitation of Cr particles.

关键词： CuCr合金铜合金内生复合材料机械性能合金化电导率

3D Casson nanofluid flow over slendering surface in a suspension of gyrotactic microorganisms with Cattaneo-Christov heat flux

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Applied Mathematics and Mechanics(English Edition) 2018年第5期39卷 623-638页

作者： V.NAGENDRAMMA C.S.k.RAJU B.MALLIkARJUNA S.A.SHEHZAD A.LEELARATHNAM Department of Mathematics SPMVV University Department of Mathematics GITAM University Department of Mathematics BMS College of Engineering Department of Mathematics COMSATS Institute of Information Technology

A mathematical model is proposed to execute the features of the non-uniform heat source or sink in the chemically reacting magnetohydrodynamic （MHD） Casson fluid across a slendering sheet in the presence of microorganisms and Cattaneo-Christov heat flux. Multiple slips （diffusion, thermal, and momentum slips） are applied in the modeling of the heat and mass transport processes. The Runge-kutta based shooting method is used to find the solutions. Numerical simulation is carried out for various values of the physical constraints when the Casson index parameter is positive, negative, or infinite with the aid of plots. The coefficients of the skin factors, the local Nusselt number, and the Sherwood number are estimated for different parameters, and discussed for engineering interest. It is found that the gyrotactic microorganisms are greatly encouraged when the dimensionless parameters increase, especially when the Casson fluid parameter is negative. It is worth mentioning that th~ velocity profiles when the Casson fluid parameter is positive are higher than those when the Casson fluid parameter is negative or infinite, whereas the temperature and concentration fields show exactly opposite phenomena.

关键词： microorganisms multiple slip Casson fluid Cattaneo-Christov heat flux,slendering sheet

Petrogenesis of the diamondiferous Pipe-8 ultramafic intrusion from the Wajrakarur kimberlite field of Southern India and its relation to the worldwide Mesoproterozoic(~1.1 Ga) magmatism of kimberlite and related rocks

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Geoscience Frontiers 2020年第3期11卷 793-805页

作者： Ashish Dongre k.S.Viljoen G.Belyanin Petrus Le Roux M.Malandkar Department of Geology Savitribai Phule Pune UniversityPune411007India Department of Geology University of JohannesburgP.O.Box 524Auckland Park2006South Africa Department of Geology University of Cape TownRondebosch7700South Africa Department of Geology Institute of ScienceAurangabad431004India

Detailed mineralogy,bulk rock major,trace and Sr-Nd isotope compositions,and ^(40)Ar/^(39)Ar dating of the Pipe-8 diamondiferous ultramafic intrusion in the Wajrakarur cluster of southern India,is *** on the presence of Ti-rich phlogopite,high Na/k content in amphibole,Al-and Ti-rich diopside,a titanomagnetite trend in spinel and the presence of Ti-rich schorlomite garnet and carbonates in the groundmass,the Pipe-8 intrusion is here more precisely classified as an ultramafic lamprophyre(i.e.,aillikite).An aillikite affinity of the Pipe-8 intrusion is further supported by the bulk rock major and trace element and Sr-Nd isotope ***-Nd isotope data are consistent with a common,moderately depleted upper mantle source region for both the Pipe-8 aillikite as well as the Wajrakarur kimberlites of southern India.A phlogopite-rich groundmass ^(40)Ar/^(39)Ar plateau age of 1115.8±7.9 Ma(2σ) for the Pipe-8 intrusion falls within a restricted 100 Ma time bracket as defined by the 1053-1155 Ma emplacement ages of kimberlites and related rocks in *** presence of ultramafic lamprophyres,carbonatites,kimberlites,and olivine lamproites in the Wajrakarur kimberlite field requires low degrees of partial melting of contrasting metasomatic assemblages in a heterogeneous sub-continental lithospheric *** widespread association of kimberlite and other mantle-derived magmatism during the Mesoproterozoic(ca.1.1 Ga) have been interpreted as being part of a single large igneous province comprising of the kalahari,Australian,West Laurentian and Indian blocks of the Rodinia supercontinent that were in existence during its *** India only kimberlite/lamproite/ultramafic lamprophyre magmatism occurred at this time without the associated large igneous provinces as seen in other parts of *** may be because of the separated paleo-latitudinal position of India from Australia during the assembly of *** is speculated that the presence of a large

关键词： kimberlite and related rocks Ultramafic lamprophyre Lamproites Wajrakarur kimberlite field Mantle plume Rodinia supercontinent

Bioleaching of copper from pre and post thermally activated low grade chalcopyrite contained ball mill spillage

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Frontiers of Environmental Science & Engineering 2013年第2期7卷 281-293页

作者： Sandeep PANDA Nilotoala PRADHAN Umaballav MOHAPATRA Sandeep k. PANDA Swagat S.RATH Danda S. RAO Bansi D. NAYAk Lala B. SUkLA Barada k. MISHRA CSIR-Institute of Minerals and Materials Technology Bhubaneswar 751013 India Department of Botany North Orissa University Baripada 757003 India Regional Center of Central Tuber Crops Research Institute Bhubaneswar 751019 India

Bioleaching of a low grade chalcopyrite （ball mill spillage material） was tested for copper recovery in shake flasks. The original samples （as received） were thermally activated （600℃, 30 min） to notice the change in physico-chemical and mineralogical characteristics of the host rock and subsequently its effect on copper recovery. A mixed culture of acidophilic chemolithotrophic bacterial consortium predominantly entailing Acidithiobacillus fer- rooxidans strain was used for bioleaching studies and optimization of process parameters of both original and thermally activated samples. Mineralogical characteriza- tion studies indicated the presence of chalcopyrite, pyrite in the silicate matrix of the granitic rock. Field emission scanning electron microscopy coupled with Energy dispersive spectroscopy （FESEM-EDS） and X-ray Fluor- escence （XRF） analysis indicated mostly SiO2. With pH 2, pulp density 10% w/v, inoculum 10% v/v, temperature 30~C, 150 ***-~, 49% copper could be recovered in 30 days from the finest particle size （- 1 ~ 0.75 mm） of the original spillage sample. Under similar conditions 95% copper could be recovered from the thermally activated sample with the same size fraction in 10 days. The study revealed that thermal activation leads to volume expansion in the rock with the development of cracks, micro and macro pores on its surface, thereby enabling bacterial solution to penetrate more easily into the body, facilitating enhanced copper dissolution.

关键词： ball mill spillage thermal activation bioleaching copper

Synthesis and luminescence of Eu3+ doped nanocrystalline TiO2 spheres

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Journal of Rare Earths 2019年第11期37卷 1121-1125页

作者： M.Lysien k.Fiaczyk R.Tomala F.Granek W.Strek Institute of Low Temperature and Structure Research Polish Academy of ScienceOkolna 2Wroclaw50-422Poland XTPL S.A. Stabtowicka 147Wroctaw54-066Poland

Eu^3+doped TiO2 anatase spheres were obtained by modified sol-gel ***(110-250 nm)are composed of smaller(5-15 nm)nanocrystals and exhibit red emission under UV light *** were synthesized by multi-step method from glycolated titania *** doped(1.0 mol%)and non-doped spheres were *** optical and structural properties were compared by materials characterization methods,such as X-ray powder diffraction,transmission electron microscopy and PL *** TiO2 spheres are crystalline phase pure and exhibit high luminescence intensity.

关键词： Titanium dioxide Nanophosphors Rare earth elements Europium doped nanoparticles Luminescence

Microwave assisted synthesis & properties of nano HA-TCP biphasic calcium phosphate

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 441-445页

作者： E.Ghomash Pasand A.Nemati M.Solati-Hashjin k.Arzani A.Farzadi Department of Materials Engineering Science and Research BranchIslamic Azad UniversityTehran ***Iran Department of Biomedical Engineering Amirkabir University of TechnologyTehran 158754413Iran

Biphasic calcium phosphate （BCP） nanopowders were synthesized by using microwave and non-microwave irradiation assisted processes. The synthesized powders were pressed under a pressure of 90 MPa, and then were sintered at 1000-1200℃ for 1 h. The mechanical properties of the samples were investigated. The formed phases and microstructures were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results showed that the synthesis time was shorter, along with a more homogeneous microstructure, when the microwave irradiation assisted method was applied. The compression strength and the Young＇s modulus of the samples synthesized with microwave irradiation were about 60 MPa and 3 GPa, but those of the samples synthesized without microwave irradiation were about 30 MPa and 2 GPa, respectively. XRD patterns of the microwave irradiation assisted and non-microwave irradiation assisted nanopowders showed the coexistence of hydroxyapatite （HA） and lricalcium phosphate （TCP） phases in the system.

关键词： bioceramics calcium phosphate hydroxyapatite (HA) Wicalcium phosphate nanoparticles (TCP) mechanical properties microwave irradiation