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141.
Thin films of polymer electrolytes comprising of PVA and KOH (A) with and without the addition of zinc salts, viz., zinc acetate (B) and zinc triflate (C) as mixed cations were prepared via. solution casting method. The thermal stability and ionic conductivity of PVA–KOH solid
polymer electrolyte (A) were improved by the partial substitution of KOH with zinc salts. Among the two salts, zinc triflate was found to improve
both the physical as well as electrochemical properties of the PVA–KOH films more significantly than zinc acetate. An attempt
to optimize the ratio of various components of polymer electrolytes, viz., polymer: KOH: zinc salt was also made, based on
the dimensional stability and ionic conductivity values. Finally, the select category polymer film containing PVA–KOH–zinc
triflate (C) in an optimum ratio of 40:35:25 was deployed in coin cell fabrication and subjected to charge–discharge studies with a view
to demonstrate the possible electrochemical reversibility characteristics. Based on the encouraging results obtained from
the cycling study, C type films [PVA–KOH–zinc triflate] qualify themselves as potential polymer electrolytes for use in rechargeable Zn/AgO polymer
batteries. 相似文献
142.
ZnCo2O4 nanomaterial was prepared by co-precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscope
(SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge–discharge tests at various
current densities. It is shown that the crystal structure and surface morphology play an important role in the enhancement
of the specific capacitance. The TEM results clearly indicate that the prepared material shows aggregated particles. The particle
size powder was about 50 nm, and SEM pictures indicate a porous morphology. The electrochemical behavior of ZnCo2O4 was characterized by mixing equal proportion of carbon nanofoam (CNF). From CV, it is concluded that the combination of redox
and pseudo-capacitance increases the specific capacitance up to 77 F g−1 at 5 mV s−1 scan rate. The ZnCo2O4-based supercapacitor cell has good cyclic stability and high coulombic efficiency. 相似文献
143.
5,6-Dihydrobenz[c]acridines were synthesized by the reaction of 1-chloro-3,4-dihydro-2-naphthaldehyde with aromatic amines under three different conditions:
- a.
- Thermolysis of 1-chlorovinyl-(N-aryl)imines prepared from 1-chloro-3,4-dihydro-2-naphthaldehyde.
- b.
- Acid catalyzed cyclization of 1-(N-aryl)amino-3,4-dihydro-2-naphthaldehydes.
- c.
- Thermolysis of N-arylenaminoimine hydrochlorides derived from 1-chloro-3,4-dihydro-2-naphthaldehyde in DMF medium.
144.
Atiyeh Bayani Karthikeyan Rajagopal Abdul Jalil M. Khalaf Sajad Jafari G.D. Leutcho J. Kengne 《Physics letters. A》2019,383(13):1450-1456
Analyzing chaotic systems with coexisting and hidden attractors has been receiving much attention recently. In this article, we analyze a four dimensional chaotic system which has a plane as the equilibrium points. Also this system is of the group of systems that have coexisting attractors. First, the system is introduced and then stability analysis, bifurcation diagram and Largest Lyapunov exponent of this system are presented as methods to analyze the multistability of the system. These methods reveal that in some ranges of the parameter, this chaotic system has three different types of coexisting attractors, chaotic, stable node and limit cycle. Some interesting dynamics properties such as reversals of period doubling bifurcation and offset boosting are also presented. 相似文献
145.
Hamid Reza Abdolmohammadi Abdul Jalil M Khalaf Shirin Panahi Karthikeyan Rajagopal Viet-Thanh Pham Sajad Jafari 《Pramana》2018,90(6):70
Nowadays, designing chaotic systems with hidden attractor is one of the most interesting topics in nonlinear dynamics and chaos. In this paper, a new 4D chaotic system is proposed. This new chaotic system has no equilibria, and so it belongs to the category of systems with hidden attractors. Dynamical features of this system are investigated with the help of its state-space portraits, bifurcation diagram, Lyapunov exponents diagram, and basin of attraction. Also a hardware realisation of this system is proposed by using field programmable gate arrays (FPGA). In addition, an electronic circuit design for the chaotic system is introduced. 相似文献
146.
Karthikeyan Rajagopal Sajad Jafari Akif Akgul Anitha Karthikeyan 《Nonlinear dynamics》2018,93(3):1087-1108
In this paper, we report a new chaotic jerk system which shows self-excited and hidden oscillations depending on its parameters. Dynamic analysis shows that the proposed system exhibits multi-stability and coexisting attractors. To study the effect of time delays on the multi-stability feature of the system, we introduce multiple time delays in the third state variable. Investigation of dynamical properties of the time-delayed system shows the disappearance of multi-stability. Such a feature has not been reported earlier in the literatures. 相似文献
147.
Ramaiyer Venkatraman Haamid Ameera Lungile Sitole Erick Ellis Frank R. Fronczek Edward J. Valente 《Journal of chemical crystallography》2009,39(10):711-718
Abstract The structures of eight related thio(semi)carbazones are described. These are syn,1E-2-acetylpyrazine-3-thiosemicarbazone (1), syn,1E,4Z-2-acetylpyrazine-4-ethyl-3-thiosemicarbazone, (2) and syn,1Z-2-acetylpyrazine-4,4-dimethyl-3-thiosemicarbazone (3), syn,1E,4Z-2-acetylthiazole-4-phenyl-3-thiosemicarbazone (4), syn,1Z-phenyl-4,4-dimethyl-3-thiosemicarbazone (5), syn,1E,4Z-phenyl-4-methyl-3-thiosemicarbazone (6), syn,1E,4Z-phenyl-4-ethyl-3-thiosemicarbazone (7), syn,1E,4Z-2-acetophenone-5-(N-aminothionyl)-3-thiocarbazone (8). Crystal data: for 1: triclinic, P-1, a = 5.4053(10) ?, b = 7.435(3) ?, c = 11.772(4) ?, α = 81.70(3)°, β = 82.59(2)°, γ = 77.38(2)°, and Z = 2: for 2: triclinic, P-1, a = 7.322(3) ?, b = 7.8239(16) ?, c = 9.783(4) ?, α = 87.73(2)°, β = 79.46(3)°, γ = 80.41(2)°, and Z = 2; for 3: orthorhombic, Pnma, a = 13.5210(15) ?, b = 6.6914(5) ?, c = 11.7214(10) ?, and Z = 4; for 4: triclinic, P-1, a = 5.7058(7) ?, b = 9.8776(15) ?, c = 11.869(2) ?, α = 76.389(12)°, β = 86.364(13)°, γ = 88.322(12)°, and Z = 2; for 5: triclinic, P-1, a = 7.5362(3) ?, b = 8.6331(4) ?, c = 9.8753(4) ?, α = 91.401(4)°, β = 102.532(4)°, γ = 110.540(4)°, and Z = 2; for 6: monoclinic, P2(1)/c, a = 10.7178(4) ?, b = 5.5866(2) ?, c = 18.7647(9) ?, β = 104.392(5)°, and Z = 4; for 7: monoclinic, P2(1)/c, a = 8.9557(3) ?, b = 9.7418(4) ?, c = 13.6864(5) ?, β = 94.044(4)°, and Z = 4; for 8: triclinic, P-1, a = 9.8091(5) ?, b = 10.6173(4) ?, c = 16.4691(7) ?, α = 75.540(4)°, β = 80.305(4)°, γ = 65.192(4)°, and Z = 4. Structures 1, 2, 4, 5, 7, and 8 form intramolecular N4–H···N1 hydrogen-bonds. Structures 3 and 5 exist in the tautomeric form in which N1 is protonated.
Graphical Abstract Structures of thio(semi)carbazones were found to fall into two categories: those with intramolecular N4-H…N1 hydrogen-bonds,
and those which show a tautomeric form in which N1 is protonated.
相似文献
148.
Karthikeyan B Saravanan B 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(3):619-623
Raman spectra of phenoxyacetic acid and chlorine substituted phenoxyacetic acids viz., o-chlorophenoxyacetic acid, p-chlorophenoxyacetic acid and 2,6-dichlorophenoxyacetic acid have been analysed with the aid of abinitio theoretical calculations. The effect of chlorine substituents on the Raman spectra of phenoxyacetic acid have also been analysed by considering some important vibrational modes. 相似文献
149.
Parasuraman Karthikeyan Sythana Suresh Kumar Aswar Sachin Arunrao Muskawar Prashant Narayan Pundlik Rambhau Bhagat 《Research on Chemical Intermediates》2013,39(3):1335-1342
An environmentally benign, cheap and reusable L-amino acid functionalized ionic liquid [L-AAIL]/AlCl3 was found to be an effective catalyst for the synthesis of 3,4-dihydropyrimidine-2-(1H)-thione derivatives in good to excellent yield under solvent-free condition. Compared with the classical Biginelli reactions, this method consistently enjoys the advantages of mild reaction conditions, easy work-up, and short reaction time. These one-pot three-component Biginelli products could be separated easily from the catalyst–water system, and the catalyst could be reused at least five times without noticeably reducing catalytic activity. 相似文献
150.
A microwave-assisted persulfate oxidation method followed by ion chromatographic determination of nitrate was developed for total nitrogen determination in atmospheric wet and dry deposition samples. Various operating parameters such as oxidation reagent concentrations, microwave power, and extraction time were optimized to maximize the conversion of total nitrogen to nitrate for subsequent chemical analysis. Under optimized conditions, 0.012 M K2S2O8 and 0.024 M NaOH were found to be necessary for complete digestion of wet and dry deposition samples at 400 W for 7 min using microwave. The optimized extraction method was then validated by testing different forms of organic nitrogen loaded to pre-baked filter substrates and NIST SRM 1648 (urban particulate matter), and satisfactory results were obtained. In the case of wet deposition samples, standard addition experiments were performed. The suitability of the method for real-world application was assessed by analyzing a number of wet and dry deposition samples collected in Singapore during the period of March-April 2007. The organic nitrogen content was 15% (wet) and 30% (dry) of the total nitrogen. During the study period, the estimated wet fluxes for nitrate (NO3−), ammonium (NH4+), organic nitrogen (ON), and total nitrogen (TN) were 16.1 ± 6.5 kg ha−1 year−1, 11.5 ± 5.7 kg ha−1 year−1, 3.8 ± 1.5 kg ha−1 year−1and 31.5 ± 13.2 kg ha−1 year−1, respectively, while the dry fluxes were 2.5 ± 0.8 kg ha−1 year−1, 1.4 ± 0.9 kg ha−1 year−1, 2.3 ± 1.4 kg ha−1 year−1 and 7.5 ± 2.6 kg ha−1 year−1, respectively. 相似文献