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A three-level central composite design of the Response Surface Methodology and the Artificial Neural Network-linked Genetic
Algorithm were applied to find the optimum operating conditions for enhanced production of l-asparaginase by the submerged fermentation of Aspergillus terreus MTCC 1782. The various effects of the operating conditions, including temperature, pH, inoculum concentration, agitation
rate, and fermentation time on the experimental production of l-asparaginase, were fitted to a second-order polynomial model and non-linear models using Response Surface Methodology and
the Artificial Neural Network, respectively. The Artificial Neural Network model fitted well, achieving a higher coefficient
of determination (R
2 = 0.999) than the second-order polynomial model (R
2 = 0.962). The l-asparaginase activity (38.57 IU s mL−1) predicted under the optimum conditions of 32.08°C, pH of 5.85, inoculum concentration of 1 vol. %, agitation rate of 123.5
min−1, and fermentation time of 55.1 h was obtained using the Artificial Neural Networklinked Genetic Algorithm in very close agreement
with the activity of 37.84 IU mL−1 achieved in confirmation experiments. 相似文献
3.
Raja DS Paramaguru G Bhuvanesh NS Reibenspies JH Renganathan R Natarajan K 《Dalton transactions (Cambridge, England : 2003)》2011,40(17):4548-4559
Four 2-oxo-1,2-dihydroquinoline-3-carbaldehyde N-substituted thiosemicarbazone ligands (H(2)-OQtsc-R, where R = H, Me, Et or Ph) and their corresponding new copper(II) complexes [CuCl(2)(H(2)-OQtsc-H)]·2H(2)O (1), [CuCl(2)(H(2)-OQtsc-Me)]·2H(2)O (2), [CuCl(2)(H(2)-OQtsc-Et)(CH(3)OH)]Cl (3) and [CuCl(H-OQtsc-Ph)]·CH(3)OH (4) have been synthesized in order to correlate the effect of terminal N-substitution on coordination behaviour, structure and biological activity. Single crystal X-ray diffraction studies revealed that the complexes 1, 2 and 3 have square pyramidal geometry around the central metal ion. In the complexes 1 and 2, the copper ion is coordinated by the ligand with ONS donor atoms, one chloride ion in apical position and the other chloride in the basal plane. Complex 3 consists of [CuCl(2)(H(2)-OQtsc-Et)(CH(3)OH)](+) cation and a chloride as counter ion. The copper ion is coordinated by the ligand with ONS donor atoms and by one chloride ion in the basal plane. One methanol molecule is bonded through its neutral oxygen in the apical position. Complex 4 is square planar with the ligand coordinating through uni-negative tridentate ONS(-) and by one chloride ion in the basal plane. The binding of complexes with lysozyme protein was carried out by fluorescence spectroscopy. Investigations of antioxidation properties showed that all the copper(II) complexes have strong radical scavenging properties. The cytotoxicity of the complexes 3 and 4 against NIH 3T3 and HeLa cell lines showed that synergy between the metal and ligands results in a significant enhancement in the cell death with IC(50) of ~10-40 μM. A size dependence of substitution at terminal N in the thiosemicarbazones on the biological activities of the complexes has been observed. 相似文献
4.
A detailed investigation has been made on the possibility of synthesizing LiNiO2 through different methods using a variety of precursors and varying heat treating conditions with a view to identify a suitable
method to synthesize LiNiO2 and to understand the influence of synthesis method and the nature of the precursors towards the performance characteristics
of LiNiO2. In this regard, four different methods,viz., solid-state, organic precursors, solution combustion and microwave methods were adopted involving suitable combinations
of lithium and nickel precursors. All the synthesized compounds were characterized for their phase purity (PXRD), local cation
environment (FTIR), particle size, surface area, and electrochemical behavior (charge-discharge). Based on the results obtained
especially from PXRD and charge-discharge studies, the “all-hydroxide” precursors of Li and Ni were found to be effective
in yielding battery active LiNiO2 as far as the solid-state and microwave-assisted methods are concerned. With regard to solution synthesis methods, citrate
precursor and the combustion method involving hydrazine hydrate fuel were found to yield better performing LiNiO2, compared to the rest of the combinations attempted in both categories. However, among the wet chemistry based solution methods
the present study recommends solution combustion method with hydrazine hydrate as fuel to synthesize electrochemically active
LiNiO2 as it was found to exhibit a stable discharge capacity of 177 mAh/g at least up to 20 cycles. 相似文献
5.
N. Kalaiselvi M. Ashok Kumar M. S. Prasath N. G. Renganathan M. Raghavan N. Muniyandi 《Ionics》2002,8(5-6):447-452
Li2CoMn3O8, a 5 V cathode material used in rechargeable lithium batteries, has been synthesized by adopting a novel technique of using
fuels along with the nitrate reactants. The effect of the fuel on the synthesis of Li2CoMn3O8 has been analyzed in terms of the physical and electrochemical properties of the final product formed by various methods
such as solid-state carbonate fusion and the solution route using acetate and nitrate precursors. Powder X-ray diffraction
FT IR spectrum, particle size, surface area and SEM analysis were carried out. The combustion method, also known as selfpropagating
high temperature (SPHT) method, has been employed in the present study by using nitrate mixtures of the respective salts and
a nitrogeneous fuel (urea or glycine) at a temperature of 300 °C for 3 hrs. The nitrate reactants without the addition of
fuel gave only a deliquescent product even at elevated temperature (600 °C) thus indicating the necessity of fuels. Similar
attempts using acetate reactants with and without the addition of nitrogeneous fuels were made separately in order to find
out the necessity of fuel also in this case. The characterization of the product in terms of purity, single-phase formation
and surface morphology suggested that the fuel played no role in the case of the acetate precursors. A comparative study was
made on the products obtained by the acetate precursor, combustion method and the conventional carbonate method. Among the
three methods, the combustion method with glycine as fuel yielded the spinel phase with high purity Li2CoMn3O8 with superior electrochemical behavior both in terms of high cell voltage and good cycle life behavior. 相似文献
6.
Monofluoro dimethyl glutarate has been successfully synthesized for the first time by electrochemical fluorination. It is
done in an undivided polypropylene cell with platinum electrodes. Initially at three different current densities, dimethyl
glutarate is subjected to electrofluorination. Maximum yield of monofluoro product is obtained at 15 mA cm−2. Selecting this current density, electrosynthesis is done at three different charges. Maximum yield of 71.5% of the monofluoro
product is obtained with a conversion efficiency of 95.2% when the charge of 6 F/mol is passed. The synthesized product is
characterized using Fourier transform infrared (FTIR), gas chromatography/mass spectrometry (GC/MS), and nuclear magnetic
resonance (NMR). The product purity and composition are ascertained using GC/MS. The attachment of fluorine to methylene group
is indicated using FTIR data. From NMR studies, the environment of fluorine in the neighborhood of carbon and hydrogen has
been established. Results are discussed in the paper. 相似文献
7.
In this paper, an approach to achieve fault diagnosis and Fault Tolerant Control in a typical bottle-filling plant using event based techniques is discussed. For this purpose, the plant is modeled using Hybrid Petri nets which enable study and analysis with regard to the working of the plant. Once effective modeling is done based on two different case studies considered, new algorithms are proposed to achieve fault diagnosis and Fault Tolerant Control on the models developed. Finally, performance measures with regard to the models proposed are evaluated to check the correctness of the models developed. Both analytical and numerical results are obtained which are highly useful to understand plant behavior. 相似文献
8.
R. Bharathikannan A. Chandramohan M. A. Kandhaswamy J. Chandrasekaran R. Renganathan V. Kandavelu 《Crystal Research and Technology》2008,43(6):683-688
The organic NLO material 2‐nitro aniline and picric acid (2NAP) was synthesized, needle shaped single crystals of dimension 10 × 1 × 0.8 mm‐3 were grown by slow evaporation solution growth technique from the saturated solution of the title compound in chloroform at ambient temperature. The material was characterized through elemental analysis, powder XRD, 1H NMR, 13C NMR and FTIR techniques. The various planes of reflection have been identified from the XRD powder pattern. The formation of the charge transfer complex was confirmed by UV‐VIS spectroscopy. The thermal stability of the crystals was investigated using TG/DTA analyses techniques. The second harmonic generation (SHG) efficiency of the material was estimated using Nd: YAG laser as source. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
Kathiravan A Renganathan R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(3):1080-1083
The adsorption of riboflavin on the surface of TiO(2) colloidal particles and the electron transfer process from its singlet excited state to the conduction band of TiO(2) were examined by absorption and fluorescence quenching measurements. The apparent association constants (K(app)) were determined. The quenching mechanism is discussed involving electron transfer from riboflavin to TiO(2). 相似文献
10.
The interaction of colloidal TiO2 nanoparticles with calf thymus-DNA was studied by using absorption, FT-IR, steady state and time resolved fluorescence spectroscopic techniques. The apparent association constant has been deduced (Kapp = 2.85 × 103 M−1) from the absorption spectral changes of the DNA-colloidal TiO2 nanoparticles using the Benesi–Hildebrand equation. Addition of colloidal TiO2 nanoparticles quenched the fluorescence of EtBr–DNA. The number of binding sites (n = 0.97) and the apparent binding constant (K = 6.68 × 103 M−1) were calculated from relevant fluorescence quenching data. The quenching, through a static mechanism, was confirmed by time resolved fluorescence spectroscopy. 相似文献