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High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayer (ML) up to 600 °C have been studied and reported in this paper. Ti/Ni multilayer samples having constant layer thicknesses of 50 Å each are deposited on float glass and Si(1 1 1) substrates using electron-beam evaporation technique under ultra-high vacuum (UHV) conditions at room temperatures. The micro-structural parameters and their evolution with temperature for as-deposited as well as annealed multilayer samples up to 600 °C in a step of 100 °C for 1 h are determined by using X-ray diffraction (XRD) and grazing incidence X-ray reflectivity techniques. The X-ray diffraction pattern recorded at 300 °C annealed multilayer sample shows interesting structural transformation (from crystalline to amorphous) because of the solid-state reaction (SSR) and subsequent re-crystallization at higher temperatures of annealing, particularly at ≥400 °C due to the formation of TiNi3 and Ti2Ni alloy phases. Sample quality and surface morphology are examined by using atomic force microscopy (AFM) technique for both as-deposited as well as annealed multilayer samples. In addition to this, a temperature dependent dc resistivity measurement is also used to study the structural transformation and subsequent alloy phase formation due to annealing treatment. The corresponding magnetization behavior of multilayer samples after each stage of annealing has been investigated by using Magneto-Optical Kerr Effect (MOKE) technique and results are interpreted in terms of observed micro-structural changes. 相似文献
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P. Ganeshan P. Ramshankar K. Raja 《International Journal of Polymer Analysis and Characterization》2018,23(3):271-277
Natural fibers are identified as one of the effective alternatives for reinforcing the polymer matrices on account of their sustainability and renewable characteristics by replacing the synthetic fibers. This study is intended to apprehend the properties of the fibers derived from the stem of Calotropis gigantea plant. The functional groups of biopolymers were recognized by Fourier transform infrared spectrum. The crystalline nature of the cellulose that represents the mechanical strength and integrity of the fibers was found from the X-ray diffraction, whereas the thermal behavior was studied by thermogravimetric analysis. Scanning electron microscope was used to study the morphology of the fibers. The results of these analytical studies have shown that the crystallinity index of the fibers was 56.08% and the fibers were able to withstand a temperature of about 220°C proving that the fibers can be used as effective reinforcements for polymer matrices similar to the commonly used bio-fibers. 相似文献
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Paramasivam Manisankar Ganeshan Selvanathan Chinnapyian Vedhi 《International journal of environmental analytical chemistry》2013,93(6):409-422
Cyclic voltammetric studies of isoproturon and carbendazim using polypyrrole modified glassy carbon electrode were carried out. The electrode and reaction conditions, which yielded maximum current signal, were selected for the development of stripping voltammetric procedure for the determination of the pesticides. The oxidation peak around 1.3?V obtained for isoproturon and carbendazim while employing polypyrrole modified electrode showed maximum current response. This peak was chosen for stripping analysis using square wave mode. The experimental parameters were optimized and the calibration plot was obtained. The LOD was 0.5?ng?mL?1 for isoproturon and 5?ng?mL?1 for carbendazim. The relative standard deviation for 5 identical measurements was 2.81% and 3.33% for isoproturon and carbendazim respectively. The applicability of the method was verified by determining the pesticides in spiked soil and water samples. 相似文献
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AgNO3 Catalyzed Regio‐Selective Synthesis of 3‐Alkyl/Aryl‐idene‐3,4‐dihydro‐4‐tosyl‐2H‐1,4‐Benzoxazine: Novel Anti‐Tubercular Scaffolds 下载免费PDF全文
Sivanandhan Karunanidhi Rajshekhar Karpoormath Milan Bera Rajesh A. Rane Mahesh B. Palkar 《Journal of heterocyclic chemistry》2016,53(5):1611-1616
A facile and efficient method for the construction of 3‐alkyl/aryl substituted 1,4‐benzoxazine and benzoxazepine via AgNO3 catalyzed cyclization of propargyloxy sulfonamides and their anti‐tubercular activity against Mycobacterium tuberculosis H37RV is described. This cyclization proceeds through 6‐exo‐dig manner to generate the products in moderate to good yields. 相似文献
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This paper investigates how the mean and variance of lead time change with the number of suppliers. Using known analytical results for the means and variances of the ‘first’ and ‘spacing’ lead times, we give simple decision rules to find the optimal numbers of suppliers when lead times are uniformly or exponentially distributed. 相似文献
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Antifungal activity and isomerization of octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa
Bioassay monitored HPLC assisted isolation and purification of the chief antifungal fraction of the leaves of Ipomoea carnea subsp. fistulosa (Convulvulaceae) were achieved using Colletotrichum gloeosporioides and Cladosporium cucumerinum as test organisms. The activity of the purified fraction was further confirmed by the dose dependent inhibition of the spore germination of Alternaria alternata and A. porri. The active fraction was identified as a mixture of (E)-octadecyl p-coumarate and (Z)-octadecyl p-coumarate. The two isomers were detected on an HPLC column with substantially different retention times, but once eluted from the column, one form was partly converted to the other in daylight. Conclusive evidence for the structures and their isomerization were obtained from the HPLC behavior, IR, UV, HRESIMS, CIMS and and NMR spectral data. Important 1H NMR and 13C NMR signals could be separately assigned for the isomers using 2D NMR techniques. 相似文献
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Ramkumar Govindaraju Asokan Ramasamy Ramya Suseenther Gayathri Ganeshan 《Journal of Cluster Science》2021,32(5):1185-1190
Journal of Cluster Science - Indiscriminate use of synthetic chemicals for pest management in agriculture leads to resistance development by the pests in addition to being toxic to non target... 相似文献
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Poissier A Ganeshan S Fernández-Serra MV 《Physical chemistry chemical physics : PCCP》2011,13(8):3375-3384
The hydrogen bond interaction between water molecules adsorbed on a Pd <111> surface, a nucleator of two dimensional ordered water arrays at low temperatures, is studied using density functional theory calculations. The role of the exchange and correlation density functional in the characterization of both the hydrogen bond and the water-metal interaction is analyzed in detail. The effect of non local correlations using the van der Waals density functional proposed by Dion et al. [M. Dion, H. Rydberg, E. Schr?der, D. C. Langreth and B. I. Lundqvist, Phys. Rev. Lett., 2004, 92, 246401] is also studied. We conclude that the choice of this potential is critical in determining the cohesive energy of water-metal complexes. We show that the interaction between water molecules and the metal surface is as sensitive to the density functional choice as hydrogen bonds between water molecules are. The reason for this is that the two interactions are very similar in nature. We make a detailed analogy between the water-water bond in the water dimer and the water-Pd bond at the Pd <111> surface. Our results show a strong similarity between these two interactions and based on this we describe the water-Pd bond as a hydrogen bond type interaction. These results demonstrate the need to obtain an accurate and reliable representation of the hydrogen bond interaction in density functional theory. 相似文献
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Shanci Chen Changquan Tang Zhigang Yin Yunlong Ma Dongdong Cai Dhanavel Ganeshan Qingdong Zheng 《中国化学》2013,(11):1409-1417
A ladder-type diindenopyrazine (IPY) was synthesized and used as a building block for constructing conjugated copolymers. Three copolymers based on the IPY moiety were obtained via the Suzuki coupling reaction with dif- ferent monomers, including 4,7-dithien-2-yl-2,1,3-benzothiadiazole (DBT), 5,8-dithien-2-yl-2,3-diphenylquinoxa- line (DTQ), and 5,8-dithien-2-yl-2,3-di(4-fluorophenyl)quinoxaline (DFTQ). The obtained polymers were charac- terized by 1H NMR spectroscopy, UV-Vis absorption spectroscopy, cyclic voltammetry, and gel permeation chro- matography (GPC). Owing to the four solubilizing alkyl chains on the IPY unit, all the three copolymers have good solubility in common solvents. These polymers have deep-lying HOMO energy levels in the range of-5.55-5.60 eV, and exhibit field-effect mobilities as high as 0.006 cm2.V-l.s i. Photovoltaic applications of these polymers as light-harvesting and hole-conducting materials were investigated in conjunction with [6,6]-phenyl-C6rbutyric acid methyl ester (PC61BM). Both conventional and inverted devices were fabricated based on these three polymers. A power conversion efficiency (PCE) of 2.53% and a high open-circuit voltage of 1.00 V were obtained under simu- lated solar light AM 1.5 G (100 mW/cm2) from an inverted solar cell with an active layer containing 25 wt% lad- der-type IPY containing copolymer (PIPYDTQ) and 75 wt% PC61BM. Moreover, a high open-circuit voltage of 1.02 V and a PCE of 2.40% were achieved from a conventional solar cell based on PIPYDTQ. 相似文献