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Synthesis and characterization of acidic properties of Al-SBA-15 materials with varying Si/Al ratios
G. Muthu Kumaran Shelu Garg Kapil Soni Manoj Kumar J.K. Gupta L.D. Sharma K.S. Rama Rao G. Murali Dhar 《Microporous and mesoporous materials》2008,114(1-3):103-109
Al-SBA-15 of varying Si/Al ratios in the range 11.4–78.4 was synthesized using tri-block copolymer P123. The calcined materials were examined by XRD, pore size distribution, surface area, 27Al NMR spectroscopy. The acidity and acid strength distribution were studied using microcalorimetric adsorption of NH3. The acidic properties were also examined by cumene cracking reaction as a function of Si/Al ratios. Systematic variation of acidity and activity was observed as a function of Si/Al ratio. The initial heats of NH3 adsorption correlated well with activity indicate that acid sites with ΔH > 100 kJ/mole is responsible for cumene cracking activity. Linear correlations were obtained with total acidity and cumene cracking activities. The tetrahedral aluminum was found to be responsible for the observed acidities and catalytic activities. 相似文献
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The Journal of Supercomputing - Blockchain technology with its inherent security features revolutionizes the field of distributed networks and has become one of the significant areas of research.... 相似文献
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Charu Singh Maarten Venter Rajesh Kumar Muthu David Brown 《International Journal of Speech Technology》2018,21(4):851-859
These days’ speech processing devices like voice-controlled devices, radio, and cell phones have gained more popularity in the area of military, audio forensics, speech recognition, education and health sectors. In the real world, speech signal during communication always contains background noise. The main task of speech related applications is voice activity detection (VAD) which include speech communication, speech recognition, and speech coding. Noise-reduction schemes for speech communication may increase the quality of speech and improve working efficiency in military aviation. Most of the developed algorithms can improve the quality of speech but unable to remove the background noise from the speech. This study provides researchers with a summary of the challenges in speech communication with background noise and provides research directions in the area of military personnel and workforces who work in noisy environments. Results of the study reveal that the DSP-based voice activity detection and background noise reduction algorithm reduced the spurious values of the speech signal. 相似文献
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Jia Mao Qi Sun Xi Wang BalaAnand Muthu Sujatha Krishnamoorthy 《Computational Intelligence》2024,40(1):e12326
Smart cities are increasingly evolving, initializing new strategies, and programs that have a significant influence on policy making and scheduling while coexisting with urban facilities. To recognize urban planning offers to a smarter city context, it is now necessary to understand the contribution of the smart city in overall urban planning and vice versa. Currently, transportation has been seen as a connection to all aspects of life across the world. This article presents the results of a survey testing into whether the public supports the concept of green transportation in the smart cities. The green urban mobility model has been proposed to investigate urban traffic information to characterize important features of smart mobility in the smart cities. The development of intelligent transportation systems using the proposed model that makes traffic easier in the city to transport safe and more comfortable. The experimental results suggest the required factors of green transportation and realistic behavior of smart mobility. 相似文献
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S Maruthamuthu J Chandrasekaran D Manoharan SN Karthick Hee‐Je Kim B Saravanakumar 《Polymer International》2016,65(5):584-595
Nanocolloidal polypyrrole (PPy):poly(styrene sulfonate) (PSS) particles were synthesized by chemical oxidative polymerization using 15 wt% of PSS. The highly processable polymer composite (PPy:PSS) was spin‐coated at 4000 rpm on fluorine‐doped tin oxide glass and subsequently employed as a counter electrode (CE) for dye‐sensitized solar cells (DSCs). PPy:PSS multilayer (one, three, five) CEs were treated with CuBr2 salt, which enhances the efficiency of the DSCs. Optical studies reveal that a bulkier counterion hinders interchain interactions of PPy which on salt treatment shows a moderate redshift in absorption maxima. Salt‐treated PPy:PSS films exhibit lower charge transfer resistance, higher surface roughness and better catalytic performance for the reduction of I3?, when compared with untreated films. The improved catalytic performance of salt‐treated PPy:PSS multilayer films is attributed to charge screening and conformational change of PPy, along with the removal of excess PSS. Under standard AM 1.5 sunlight illumination, salt treatment is shown to boost the efficiency of multilayer PPy:PSS composite film‐based DSCs, leading to enhanced power conversion efficiency of 6.18, 6.33 and 6.37% for one, three and five layers, respectively. These values are significantly higher (ca 50%) than those for corresponding devices without CuBr2 salt treatment (3.48, 2.90 and 2.01%, respectively). © 2016 Society of Chemical Industry 相似文献
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Muniyandi Kasipandi Jagadeesan Gayathri George Blassan P. Manoharan Ashwini Lydia Nataraj Gayathri Abrahamse Heidi Thangaraj Parimelazhagan 《Food science and biotechnology》2022,31(13):1717-1728
Food Science and Biotechnology - A rich source of nutrients, figs have a number of clinically validated benefits. This study aimed to evaluate the in vitro simulated gastrointestinal digestion, and... 相似文献
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Muthu Kumaran Gnanamani Gary Jacobs Wilson D. Shafer Dennis E. Sparks Shelley Hopps Gerald A. Thomas Burtron H. Davis 《Topics in Catalysis》2014,57(6-9):612-618
Low temperature water–gas shift (LT-WGS) was performed over various group I alkali metal (Li, Na, K, Rb, Cs) promoted cobalt carbide (Co2C) catalysts at temperatures ranging from 453 to 573 K and atmospheric pressure. Cobalt carbide (Co2C) was found to be active for the WGS reaction. The stability of the catalyst is related to the stability of the cobalt carbide phases under reaction conditions. Potassium promoted cobalt carbide catalysts exhibited higher activity and stability compared to the other alkali promoted catalysts for LT-WGS. X-ray diffraction analyses of fresh and used catalysts suggest that the origin of deactivation of the catalysts is primarily due to the chemical transition of cobalt from carbide to metal during WGS. 相似文献
10.
Solomon Sundar Manoharan Swati Sigamani John Prasanna Manju Lata Rao Ranjan Kumar Sahu 《Journal of the American Ceramic Society》2002,85(10):2469-2471
Interaction of electromagnetic radiation with a physical mixture of metal nitrates and amides/hydrazides is observed to initiate high-temperature reactions, useful for realizing several high-temperature ceramic materials. A judicious choice of such redox mixtures undergoes exothermic reactions when they couple with microwave radiation. The coupling of electromagnetic radiation with metal salts and amides/hydrazides depends on the dielectric properties of the individual components in the reaction mixture. The approach has been used to prepare γ-Fe2 O3 , Fe3 O4 , MgCr2 O4 , α-CaCr2 O4 , and La0.7 Ba0.3 MnO3 . 相似文献