Wyniki wyszukiwania - Biblioteka Nauki

1

Synthesis, characterization and analytical applications of new chelating resin containing tetracycline

100%

Singh D. K. , Srivastava M.

Chemia Analityczna

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2005

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tom Vol. 50, No. 2

377-386

EN

A new chelating resin based on phenol-formaldehyde copolymer containing tetracycline as functional species has been synthesized. The mixture of 0.1 mol of phenol, 0.2 mol of formaldehyde and 10.4 inmol of tetracycline provided the highest sorption capacity of the phenol-formaldehydc-tetracyclme system (PFTC3). Complexation properties (distribution coefficients) of PFTC3 chelating resin towards 17 metal ions has been studied in demineralized water (DMW) and 0.1 mol L-1 NaNO3 as well as buffer solutions at different pH (2-6). A tentative structure of PFTC3 was proposed and confirmed by FTIR analysis and the estimated tetracycline content. Successive separations of some pairs of metal ions have been performed. The new chelating resin has also been applied to the selectiveremoval of Fe+3 and Zr4+ from dilute aqueous solutions.

PL

Zsyntetyzowano na bazie polimeru fenolowo-formaldehydowego nowy jonit chelalujący zawierający tetracyklinę jako grupę funkcyjną. Najwyższą zdolność sorpcyjną ukiadu fenolowo-formaldchydowo-tetracyklinowego (PFTC3) uzyskano wychodząc z mieszaniny 0.1 mola fenolu, 0.2 mola formaldehydu i 10.4 mmola tetracyldiny. Zbadano zdolność komplcksowania (współczynniki podziaiu) 17-u jonów metalicznych na jonicie PFTC3 w wodzie demineralizowanej (DMW) i 0.1 mol L-1 NaNO3 oraz w roztworach buforów (pH = 2-6). Zaproponowano wstępnie strukturę PFTC3, którą potwierdziła analiza za pomocą FTIR oraz oszacowano zawartość tetracykliny w jonicie. Wykonano udane rozdzielenia par jonów metalicznych. Nowy jonit chelatujący zastosowano także do selektywnego usuwania Fe+3 i Zr4+ z rozcieńczonych roztworów wodnych.

2

Genetic Algorithm for Combined Speaker and Speech Recognition using Deep Neural Networks

80%

Kaur G. , Srivastava M. , Kumar A.

Journal of Telecommunications and Information Technology

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2018

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tom nr 2

23--31

EN

Huge growth is observed in the speech and speaker recognition ﬁeld due to many artiﬁcial intelligence algorithms being applied. Speech is used to convey messages via the language being spoken, emotions, gender and speaker identity. Many real applications in healthcare are based upon speech and speaker recognition, e.g. a voice-controlled wheelchair helps control the chair. In this paper, we use a genetic algorithm (GA) for combined speaker and speech recognition, relying on optimized Mel Frequency Cepstral Coeﬃcient (MFCC) speech features, and classiﬁcation is performed using a Deep Neural Network (DNN). In the ﬁrst phase, feature extraction using MFCC is executed. Then, feature optimization is performed using GA. In the second phase training is conducted using DNN. Evaluation and validation of the proposed work model is done by setting a real environment, and eﬃciency is calculated on the basis of such parameters as accuracy, precision rate, recall rate, sensitivity, and speciﬁcity. Also, this paper presents an evaluation of such feature extraction methods as linear predictive coding coefficient (LPCC), perceptual linear prediction (PLP), mel frequency cepstral coefﬁcients (MFCC) and relative spectra ﬁltering (RASTA), with all of them used for combined speaker and speech recognition systems. A comparison of diﬀerent methods based on existing techniques for both clean and noisy environments is made as well.

3

Plantlet formation via somatic embryogenesis and LC ESI Q-TOF MS determination of secondary metabolites in Butea monosperma (Lam.) Kuntze

51%

Sharma C. , Kumari T. , Pant G. , Bajpai V. , Srivastava M. , Mitra K. , Kumar B. , Arya K. R.

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nr 11

EN

Medicinal properties of Butea monosperma (BM) and overexploitation of bark as a rich source of flavonoids for different biological activities, development of efficient method for high frequency somatic embryos and in vitro synthesis of bioactive secondary metabolites using plant tissue culture technology is important. Initially, callus was induced from leaf explants of BM on Murashige and Skoog (MS) medium containing 0.25 mg L-1 2,4-Ddichlorophenoxyacetic acid (2,4-D) with 0.1 mg L-1 kinetin (Kn) and ascorbic acid (AA). MS half strength macronutrients and full strength micronutrients containing 0.25 mg L-1 2,4-D with 0.1 mg L-1 Kn, and 0.5 mg L-1 AA provided fragile callus with 84.0 ± 1.00 % optimal growth response. Shoot formation occurred via somatic embryogenesis through an intermediary callus phase. However, 2.1 mg L-1 thidiazuron with 0.5 mg L-1 AA provides high frequency (79.6 ± 2.02 %) of somatic embryogenesis within 5 weeks. Developed embryos when transferred to woody plant medium containing 0.5 mg L-1 AA with 3.0 mg L-1 Kn and 0.5 mg L-1 a naphthalene acetic acid responded 44.0 ± 0.00 % embryo maturation, whereas 0.5 mg L-1 Kn, 0.3 mg L-1 indole-3-butyric acid, and 0.25 mg L-1 AA induced rooting within 6 and 8 weeks, respectively. Liquid chromatography electro spray ionization quadrupole time of flight mass spectrometry (LC ESI Q-TOF MS) analysis of in vitro cultures showed similarity to those compounds identified in wild grown leaf samples known for osteogenic activity. Histological investigation through scanning electron microscopy demonstrates the developmental stages of somatic embryos, shoot bud formation, and induction of root primordial.