NOPR Collection:

Conversion of ethanol to higher alcohols on Ni/MxOy-Al2O3 (M=La, Ce, Zr, Mg and Ti) catalysts: Influence of support characteristics

2021-03-16T11:19:55Z

Title: Conversion of ethanol to higher alcohols on Ni/MxOy-Al2O3 (M=La, Ce, Zr, Mg and Ti) catalysts: Influence of support characteristics Authors: Rathinasamy, Vinayagamoorthi; Kandasamy, Thirunavukkarasu; Ramaswamy, Krishnamurthy Konda; Balasubramanian, Viswanathan; Kannan, Shanthi Abstract: A new series of alumina supported nickel (8% w/w) catalysts, modified with promoters, La₂O₃, CeO₂, ZrO₂, MgO and TiO₂, highly active for the conversion of ethanol to butanol and higher alcohols, at 200°C-220°C, in batch mode, under autogenous pressure, has been investigated. XRD and XPS results indicate the presence of metallic Ni and Ni aluminate as the active phases. H₂-TPR studies reveal that the introduction of promoters improves nickel dispersion, reducibility and moderates the metal-support interactions.TPD of ammonia and CO₂ studies establish the strong influence of the promoter oxides on the strength and population of acidic and basic sites. Ethanol conversion at 200°C varies in a narrow range, 36-42%. CeO₂ and MgO modified catalysts display maximum selectivity towards butanol (48%) and higher alcohols, (81% and 75%) in comparison with the catalyst based on pristine alumina (28.9% and 40.5%). While the selectivity for butanol and higher alcohols is governed by the basicity of the catalysts, both metal function and basicity are required to drive ethanol conversion. Moderation of acidity helps in minimizing the formation of ethylene and other gaseous products. Analysis of used catalyst indicates that the structural and active phase characteristics are retained during use. Page(s): 9-22

Enhanced adsorption of fluoride by common potters’clay surface modified by zirconium oxide particles

2021-03-16T11:17:05Z

Title: Enhanced adsorption of fluoride by common potters’clay surface modified by zirconium oxide particles Authors: Kalita, Paran Jyoti; Saikia, Jitu; Sarmah, Susmita; Goswamee, Rajib Lochan Abstract: The present study aims to enhance the fluoride removal capacity of a low cost material common potters’ clay by surface modification through oxidic particles. Zirconium oxide particles have been supported over the clay surface to achieve the objective. Results revealed that the adsorbent is very efficient in a wide pH range of 3-11.The adsorption process followed a Freundlich isotherm model signifying that the adsorption took place on the surface in a multilayer form. Kinetic study show that adsorption gained equilibrium within 120 min and it follow pseudo 2^nd order kinetics. From this study, it is found that fluoride adsorptive power of common potters’ clay can be improved through surface modification of the clay by supporting ZrO₂ particles. Page(s): 23-35

A green tactic for inhibition of corrosion on mild steel in bore well water by aqueous extract of Bauhinia Blakeana leaves

2021-03-16T11:14:54Z

Title: A green tactic for inhibition of corrosion on mild steel in bore well water by aqueous extract of Bauhinia Blakeana leaves Authors: Geetha, K; Udhayakumar, R Abstract: The impact of an aqueous extract of Bauhinia Blakeana leaves (AEBBL) in controlling the corrosion of mild steel in bore well water medium has been demonstrated by mass loss method and electrochemical measurements. The extract is characterized by Fourier-Transform Infrared Spectroscopy (FTIR) and the active ingredients present in the AEBBL are identified by Gas Chromatography-Mass Spectrometry (GC-MS). The surface morphology is examined with the help of Scanning electron microscopy (SEM) and the surface roughness analysis is done by Atomic force microscopy (AFM). Weight loss method reveals that of the extract offers a maximum corrosion inhibition efficiency of 96.62 . Potentiodynamic polarization study (PDP) and Electrochemical impedance spectroscopy (EIS) are used to study the mechanistic aspects of corrosion inhibition. Both the double layer capacitance (C_dl) and corrosion current (I_corr) values decreases while the charge transfer resistance (R_ct) value increases with the increase in concentration of AEBBL. The potentiodynamic polarisation reveal that AEBBL acts as mixed type inhibitor with primarily cathodic effectiveness. SEM and AFM documented the development of shielding coating on the mild steel surface. Page(s): 36-46

Simultaneous quantification of Daclatasvir and Sofosbuvir in human plasma and pharmacokinetic study by LCMS/MS

2021-03-16T11:08:17Z

Title: Simultaneous quantification of Daclatasvir and Sofosbuvir in human plasma and pharmacokinetic study by LCMS/MS Authors: Amarnath; Srivastava, Anupam Kumar; Ameta, Suresh C; Ameta, Rakshit Abstract: In the treatment of hepatitis C, direct-acting antivirals (DAA) are highly efficient and well tolerated with a series of DAA combinations available for treatment. A sensitive high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for the simultaneous quantification of Sofosbuvir (SOF) and Daclatasvir (DAC) in human plasma. Sofosbuvir D6 (SOF D6) and Daclatasvir ¹³C₂²H₆(DAC ¹³C₂²H₆₎are used as internal standard (IS). Quantification for both the analytes has been attained with MS-MS detection in positive ion mode using an Acquity UPLC system (Waters) equipped with Waters Xevo TQ MS system with a Gemini NX 5µ C18 (50 × 2.0mm) (Phenomenex) column, and a gradient mobile phase consisting 5 mM Ammonium Formate buffer: Acetonitrile at a flow rate of 0.300 mL/min is used as mobile phase to separate the analytes and detection is performed by electrospray ionization technique using the mass spectrometer. Full validation is performed for bio-analytical methods with respect to linearity, precision, accuracy, selectivity, carry-over, stability and dilution integrity. Linearity is obtained over a concentration range of 10.002 -3000.488 and 10.004 -3001.218 ng mL^-1 for SOF and DAC respectively by applying weighted least-squares linear regression method (1/x2). The developed method was applied successfully in bioequivalence and/or clinical studies in 48 male subjects for the simultaneous quantification of SOF and DAC. Page(s): 47-58