Search results

1

Agrobacterium-mediated transient GUS gene expression in buffel grass (Cenchrus ciliaris L.)

100%

Batra S., Kumar S.

Journal of Applied Genetics

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2003

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vol. 44

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issue 4

449-458

EN

The study was conducted to standardize a protocol for Agrobacterium-mediated genetic transformation of buffel grass (Cenchrus ciliaris L.). Embryogenic calli, produced from one-year-old mature seeds of buffel grass, were used as target cells for Agrobacterium-mediated transformation. A. tumefaciens strain LBA4404, harbouring pCAMBIA-1301 or pCAMBIA-2301, was used for co-cultivation with embryogenic calli from three genotypes (IG-3108, IG-9757 and IG-97101). Co-culturing of calli with Agrobacterium for 30 minutes, followed by co-cultivation with 0.1 mM acetosyringone for 3 days was found to be optimum for maximum transformation efficiency. Presence of acetosyringone during co-cultivation was found to be necessary for transformation. Transient GUS (-glucuronidase) gene expression was used to monitor T-DNA delivery into the target cells. Significant genotypic variations in response to transformation were observed among the tested genotypes. A very high frequency (63.3%) of GUS gene expression was obtained following Agrobacterium-mediated gene transfer into embryogenic calli. The standardized protocol would be useful for Agrobacterium-mediated genetic transformation of buffel grass with genes of agronomic importance.

2

Geopolymerisation of Mechanically Activated Lignite and Brown Coal Fly Ash

81%

Mucsi G., Molnár Z., Kumar S.

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vol. 126

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issue 4

994-998

EN

Geopolymers have been synthesized from mechanically activated lignite and brown coal fly ash. Mechanical activation of fly ash has been carried out using laboratory ball mill. To determine the structural changes in both, the fly ash and the resulted geopolymer, Fourier transform infrared spectroscopy measurements were performed. Isothermal conduction calorimetry method was applied to study the geopolymerisation reactions in mechanically non-activated (raw) and activated fly ash samples. The isothermal conduction calorimetry results showed similar peak intensity for mechanically activated (5-30 min) fly ash samples. However, the intensity of peak for 120 min milled brown coal fly ash was the highest. The compressive strength of the specimen was found to be dependent on the grinding residence time as well as composition/type of fly ash.

3

Corrosion Inhibition of Mild Steel in Nitric Acid Media by some Schiff Bases Derived from Anisalidine

81%

Saxena N., Kumar S., Sharma M. K., Mathur S. P.

Polish Journal of Chemical Technology

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2013

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vol. 15

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issue 1

61-67

EN

Corrosion inhibition performance of mild steel in nitric acid solution containing different concentration of anisalidine derivative Schiff bases viz. N- (4-nitro phenyl) p-anisalidine (SB1), N- (4-chloro phenyl) p-anisalidine (SB2), N- (4-phenyl) p-anisalidine (SB3), N- (4-methoxy phenyl) p-anisalidine (SB4), N- (4-hydroxy phenyl) p-anisalidine (SB5) has been investigated using mass loss, thermometric and potentiostate polarization technique. Inhibition efficiencies of Schiff bases have been evaluated at different acid strength. The inhibition efficiency was found larger than their parent amines. Inhibition efficiencies of synthesized Schiff bases increase with inhibitor concentration. Inhibition efficiency increases up to 98.32% with ansalidine derivative Schiff base.

4

Generation of marker-free Bt transgenic indica rice and evaluation of its yellow stem borer resistance

81%

Kumar S., Arul L., Talwar D.

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vol. 51

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issue 3

243-257

EN

We report on generation of marker-free ('lean DNA') transgenic rice (Oryza sativa), carrying minimal gene-expression-cassettes of the genes of interest, and evaluation of its resistance to yellow stem borer Scirpophaga incertulas (Lepidoptera: Pyralidae). The transgenic indica rice harbours a translational fusion of 2 different Bacillus thuringiensis (Bt) genes, namely cry1B-1Aa, driven by the green-tissue-specific phosphoenol pyruvate carboxylase (PEPC) promoter. Mature seed-derived calli of an elite indica rice cultivar Pusa Basmati-1 were co-bombarded with gene-expression-cassettes (clean DNA fragments) of the Bt gene and the marker hpt gene, to generate marker-free transgenic rice plants. The clean DNA fragments for bombardment were obtained by restriction digestion and gel extraction. Through biolistic transformation, 67 independent transformants were generated. Transformation frequency reached 3.3%, and 81% of the transgenic plants were co-transformants. Stable integration of the Bt gene was confirmed, and the insert copy number was determined by Southern analysis. Western analysis and ELISA revealed a high level of Bt protein expression in transgenic plants. Progeny analysis confirmed stable inheritance of the Bt gene according to the Mendelian (3:1) ratio. Insect bioassays revealed complete protection of transgenic plants from yellow stem borer infestation. PCR analysis of T2 progeny plants resulted in the recovery of up to 4% marker-free transgenic rice plants.

5

Reflection and transmission of plane waves between two different fluid saturated porous half spaces

81%

Kumar R., Miglani A., Kumar S.

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2011

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issue 2

6

Photo fenton like process Fe3+/(NH4)2S2O8/UV for the degradation of Di azo dye congo red using low iron concentration

81%

Devi L., Kumar S., Reddy K.

Open Chemistry

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2009

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vol. 7

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issue 3

468-477

EN

Degradation of Congo Red (CR) a di azo dye in aqueous solution is investigated by a Photo Fenton like process using Fe3+ ions as the catalyst and peroxy disulfate as the oxidant. The influence of various reaction parameters like, concentration of Fe3+ ions, concentration of the dye, concentration of ammonium persulfate, pH of the solution and the presence of hydroxyl radical scavenger are studied and optimal conditions are reported. The degradation rate decreased at higher dye concentration and at higher pH. The rate constant (k), catalytic efficiency (kc) and process efficiency (Φ) are evaluated for different concentration of Fe3+ ions. The degradation of CR by the photo Fenton like process leads to the formation of 4-Amino, 3-azo naphthalene sulphonic acid, dihydroxy substituted naphthalene, dihydroxy substituted biphenyl, phenol, quinol etc., as intermediates, based on which probable degradation mechanism is proposed. These results show that a photo Fenton like process could be useful technology for the mineralization of di azo dyes under lower concentration of iron in acidic conditions. The present process is advantageous as it lowers the sludge production resulting from the iron comple [...]

7

Synthesis of Fe_4[Fe(CN)_6]_3·14H_2O Nanopowder by Co-Precipitation Technique and Effect of Heat Treatment

61%

Rohilla S., Lal B., Sunder S., Aghamkar P., Kumar S., Aggarwal A.

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issue 4

696-700

EN

Nanopowder of iron cyanide hydrate (member of Prussian blue family) was obtained using ferric chloride and potassium cyanide in their dilute solution through co-precipitation method. The effect of thermal annealing on iron cyanide hydrate nanocrystallites have been studied in detail. The formation of Fe_4[Fe(CN)_6]_3·14H_2O and iron oxides was revealed by the Fourier transform infrared spectroscopy. The crystal structure, morphology and size of nanocrystallites were investigated by X-ray diffraction and transmission electron microscope. Results suggest that using co-precipitation technique, nanopowder of iron cyanide hydrate, in typically spherical shape, can be obtained and their thermal treatment also yield iron oxide nanocrystallites of spherical with good homogeneity. The size of the prepared nanocrystallites was found in the range 20-36 nm. It was observed that thermal treatment, typically at 800°C (4 h), iron cyanide hydrate (Fe_4[Fe(CN)_6]_3·14H_2O) nanocrystallites transformed into iron oxide (α-Fe_2O_{3,} hematite) nanocrystallites.

8

Embedded Solitons and Conservation Law with χ^{(2)} and χ^{(3)} Nonlinear Susceptibilities

52%

Savescu M., Kara A., Kumar S., Krishnan E., Zaka Ullah M., Moshokoa S., Zhou Q., Biswas A.

Acta Physica Polonica A

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2017

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vol. 131

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issue 2

297-303

EN

This paper studies embedded solitons that are confined to continuous spectrum, with χ^{(2)} and χ^{(3)} nonlinear susceptibilities. Bright and singular soliton solutions are obtained by the method of undetermined coefficients. Subsequently, the Lie symmetry analysis and mapping method retrieves additional solutions to the model such as shock waves, singular solitons, cnoidal waves, and several others. Finally, a conservation law for this model is secured through the Lie symmetry analysis.

Refine search results

Agrobacterium-mediated transient GUS gene expression in buffel grass (Cenchrus ciliaris L.)

Geopolymerisation of Mechanically Activated Lignite and Brown Coal Fly Ash

Corrosion Inhibition of Mild Steel in Nitric Acid Media by some Schiff Bases Derived from Anisalidine

Generation of marker-free Bt transgenic indica rice and evaluation of its yellow stem borer resistance

Reflection and transmission of plane waves between two different fluid saturated porous half spaces

Photo fenton like process Fe3+/(NH4)2S2O8/UV for the degradation of Di azo dye congo red using low iron concentration

Synthesis of Fe_4[Fe(CN)_6]_3·14H_2O Nanopowder by Co-Precipitation Technique and Effect of Heat Treatment

Embedded Solitons and Conservation Law with χ^{(2)} and χ^{(3)} Nonlinear Susceptibilities