NOPR Collection:

Formulation of biocomposite of ultrasonication mediated cellulose and lignin nanofibers for biomedical applications

2020-09-21T10:34:46Z

Title: Formulation of biocomposite of ultrasonication mediated cellulose and lignin nanofibers for biomedical applications Authors: Vibha, Kumari; Negi, Sangeeta Abstract: Current study deals with the synthesis of bio-composites using nanofibres of lignin and cellulose embedded in pectin. Nanofibres of lignin and cellulose were generated through ultrasonication in varying doses and polymerized with pectin in order to formulate biocomposite through atomic transfer radical polymerization technique. The average size of the cellulose and lignin nanofibers formed were of 7.38 nm and 262.1 nm, respectively on ultra-sonicating it (50% amplitude, 2 sec on and off pulses at 30 ºC) for 15 min. Biocomposite was characterized through TGA analysis, which shows thermal degradation start after 100 ºC and at 761ºC about 60% of weight loss was observed, which proved its high thermostability. Scanning electron microscopy study concluded that surface of the biocomposite was smooth and homogenous. The structural analysis using FTIR illustrated ester bond formation between the hydroxyl group of lignin and cellulose with the carboxyl groups of pectin molecules while polymerization, which imparted it thermal stability and strength. On further analysis, biocomposite has shown distinct antioxidant property, negligible cell cytotoxicity and started auto- degenerate just after 15 min in aqueous medium, therefore this can be explored in biomedical and pharmaceutical industries for controlled drug delivery and as drug carrier. Page(s): 135-142

Photoluminescence study of Sr3Y1-X(BO3)3:xTb3+ green emitting phosphor

2020-09-21T10:33:09Z

Title: Photoluminescence study of Sr3Y1-X(BO3)3:xTb3+ green emitting phosphor Authors: Hargunani, S P; Palaspagar, R S; Sonekar, R P; Omanwar, S K Abstract: Terbium doped strontium yttrium borate phosphor is prepared by solution combustion method. Structural characterization of Sr₃Y(BO₃)₃:Tb³⁺(SYB:Tb) has been carried out with X-ray powder diffraction (XRD) analysis. Particle size of 0.5–2 µm and perfect element composition were seen in SEM-EDS. Using FTIR at room temperature the presence of [BO₃]^- group; complete combustion of nitrates, organic material, absence of O-H bond were firmed up. Photoluminescence properties of the phosphor have been investigated by measuring the excitation and emission spectra. Several luminescence bands of Tb³⁺ ions are observed under 233 nm excitation wavelengths in 350–700 nm spectral region. The emission spectra were composed of three bands, in which the dominated emission of green luminescence SYB:Tb attributed to the transition ⁵D₄→⁷F₅ is centered at 543 nm. The dependence of the emission intensity on the Tb³⁺ concentration for the Sr₃Y_1-X(BO₃)₃:_xTb³⁺ (0.01 ≤ x ≤ 0.05) was studied and observed that the optimum concentration of Tb³⁺ in phosphor was 3 mol% for the highest emission intensity at 543 nm. The CIE coordinates (X=0.251363409, Y=0.736605581) fall at the border of green region in the CIE 1931 chromaticity. Page(s): 143-147

CFD-subset-FVM-based MATLAB-simulation of heat transfer in high grade cold storage augmenting cryogenic energy storage system by circulating natural gas as working fluid

2020-09-21T10:31:10Z

Title: CFD-subset-FVM-based MATLAB-simulation of heat transfer in high grade cold storage augmenting cryogenic energy storage system by circulating natural gas as working fluid Authors: Raj, A Kanni Abstract: Cryogenic Energy Storage (CES) improves power grid with renewable intermittent power sources. In CES, off-peak excess electricity liquefies air or natural gas. Cryogen is stored in large dewar tanks for long periods of time. Whenever electricity need is in peak, work is recovered from cryogen by a power cycle using waste heat. Many researchers focus on liquid air energy storage (LAES). But, natural gas is promising working fluid for CES. This paper reviews a natural gas-based CES system, coupled with a high grade cold storage (HGCS) unit. Cold that is stored at a low temperature has been used to raise efficiency and hike yield of liquefier. This paper models HGCS unit and compares output with experimental data. Impact of cold recycling has been analyzed for liquefier yield and storage efficiency. Page(s): 148-151

In Vitro antimicrobial, antioxidant activity and phytochemical screening of Paeonia emodi

2020-09-21T10:29:15Z

Title: In Vitro antimicrobial, antioxidant activity and phytochemical screening of Paeonia emodi Authors: Saklani, Sarla; Chandra, Subhash; Joshi, Abhishek Abstract: This is the first scientific report to explore the comprehensive antimicrobial activity, antioxidant activity and phytochemical screening of different fractions (petroleum ether, ethyl acetate, methanolic and water) of leaves part of P. emodi. The extraction process involved fractionation with various solvents with using AOAC method and standard techniques. Antioxidant activities of methanolic extract were examined using DPPH methods. The level of starch, sucrose and malic acid P. emodi leaves were found to be 9.5%, 5.4% and 0.47%, respectively. The methanolic extract of P. emodi leaves showed the highest activity as compared with other plants. The antimicrobial activities were tested by the disc-diffusion method. Phytochemical screening of methanolic extract leads to identification of tannins, flavonoids, polyphenols, sterols, polyterpenes and alkaloids. The present study was attempted for the first time to investigate the antimicrobial activity, antioxidant activity, thin layer chromatography and phytochemical screening of P. emodi to search for newer, safer and more potent drug. Page(s): 152-155