CHEMICAL COMPOSITION AND CHARACTERIZATION STUDIES OF CASSIA AURICULATA FLOWER EXTRACT

Objectives: The present study, aimed to determine and characterize the chemical constituents of Cassia auriculata flower extract by qualitative, quantitative and analytical techniques. Methods: Preliminary Phytochemical, total flavonoid and phenol content was determined in the methanolic extract of C.auriculata (CAFMEt) using standard methods. C-18 silica gel based column chromatography was used to purify CAFMEt using n-hexane, ethyl acetate and methanol and fraction identified by thin layer chromatography. GC-MS and FT-IR techniques used to characterize the lead fraction. Results: CAFMEt showed the presence of flavonoid and Phenols in a significant amount. Three fractions was collected from column chromatography viz., Fraction 1-3 (n-hexane: yellow) was 2.5mg, (ethyl acetate: light orange) 1.8mg and (methanol: light green) 5.67mg respectively. TLC indicated n-hexane has higher refractive factors 0.457 at yellow band and ethyl acetate fraction has 0.329 at light orange band. 14 chemical constituents were identified by GC-MS included alkanes, alcohol, esters and hydrocarbons. The major peak showed the presence of 4-(4-methylphenoxy) phenol at 22.53%. Infra red spectra revealed the presence of phenolic groups in hexane fraction. Conclusion: Further studies will be carried out the pharmacological potential of n-hexane fractions of flowers of C.auriculata

ICEF2006-1535 THE EFFECT OF SULFUR ON METHANE PARTIAL OXIDATION AND REFORMING PROCESSES FOR LEAN NOX TRAP CATALYSIS

ABSTRACT Lean NOx trap catalysts have demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N 2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as "regeneration" since the catalyst is reactivated for more NOx trapping after NOx purge. Creating the rich exhaust conditions for regeneration can be accomplished by catalytic partial oxidation of methane in the exhaust system. Furthermore, catalytic reforming of partial oxidation exhaust can enable increased quantities of H 2 which is an excellent reductant for lean NOx trap regeneration. It is critical to maintain clean and efficient partial oxidation and reforming processes to keep the lean NOx trap functioning properly and to reduce extra fuel consumption from the regeneration process. Although most exhaust constituents do not impede partial oxidation and reforming, some exhaust constituents may negatively affect the catalysts and result in loss of catalytic efficiency. Of particular concern are common catalyst poisons sulfur, zinc, and phosphorous. These poisons form in the exhaust through combustion of fuel and oil, and although they are present at low concentrations, they can accumulate to significant levels over the life of an engine system. In the work presented here, the effects of sulfur on the partial oxidation and reforming catalytic processes were studied to determine any durability limitations on the production of reductants for lean NOx trap catalyst regeneration. _______________ *Currently with Finning in Alberta, Canada ([email protected]). INTRODUCTION Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance is straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are carefully regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocated Internal Combustion Engine (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the efficiency and emissions of natural gas reciprocating engines are bein

Geometrical, electronic structure, nonlinear optical and spectroscopic investigations of 4-(phenylthio)phthalonitrile dye sensitizer for solar cells using quantum chemical calculations

The geometries, electronic structures, polarizabilities, and hyperpolarizabilities of organic dye sensitizer 4-(phenylthio)phthalonitrile were studied based on Density Functional Theory (DFT) using the hybrid functional B3LYP. Ultraviolet-Visible (UV-Vis) spectrum was investigated by using a hybrid method which combines CIS-DFT (B3LYP). The absorption bands are assigned to n→π* transitions. The results were showed 4-(phenylthio) phthalonitrile used in Dye Sensitized Solar Cells (DSSC) give a good conversion efficiency

Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications

Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance is straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are stringently regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocating Internal Combustion Engines (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). A summary of the goals for the ARES program is given in Table 1-1. ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the efficiency and emissions of natural gas reciprocating engines are being pursued. Approaches include: stoichiometric engine operation with exhaust gas recirculation and three-way catalysis, advanced combustion modes such as homogeneous charge compression ignition, and extension of the lean combustion limit with advanced ignition concepts and/or hydrogen mixing. The research presented here addresses the technical approach of combining efficient lean spark-ignited natural gas combustion with low emissions obtained from a lean NOx trap catalyst aftertreatment system. This approach can be applied to current lean engine technology or advanced lean engines that may result from related efforts in lean limit extension. Furthermore, the lean NOx trap technology has synergy with hydrogen-assisted lean limit extension since hydrogen is produced from natural gas during the lean NOx trap catalyst system process. The approach is also applicable to other lean engines such as diesel engines, natural gas turbines, and lean gasoline engines; other research activities have focused on those applications. Some commercialization of the technology has occurred for automotive applications (both diesel and lean gasoline engine vehicles) and natural gas turbines for stationary power. The research here specifically addresses barriers to commercialization of the technology for large lean natural gas reciprocating engines for stationary power. The report presented here is a comprehensive collection of research conducted by Oak Ridge National Laboratory (ORNL) on lean NOx trap catalysis for lean natural gas reciprocating engines. The research was performed in the Department of Energy's ARES program from 2003 to 2007 and covers several aspects of the technology. All studies were conducted at ORNL on a Cummins C8.3G+ natural gas engine chosen based on industry input to simulate large lean natural gas engines. Specific technical areas addressed by the research include: NOx reduction efficiency, partial oxidation and reforming chemistry, and the effects of sulfur poisons on the partial oxidation, reformer, and lean NOx trap catalysts. The initial work on NOx reduction efficiency demonstrated that NOx emissions <0.1 g/bhp-hr (the ARES goal) can be achieved with the lean NOx trap catalyst technology. Subsequent work focused on cost and size optimization and durability issues which addressed two specific ARES areas of interest to industry ('Cost of Power' and 'Availability, Reliability, and Maintainability', respectively). Thus, the research addressed the approach of the lean NOx trap catalyst technology toward the ARES goals as shown in Table 1-1

Novel adsorbent from agricultural waste (cashew NUT shell) for methylene blue dye removal: Optimization by response surface methodology

Activated carbon, prepared from an agricultural waste, cashew nut shell (CNS) was utilized as an adsorbent for the removal of methylene blue (MB) dye from aqueous solution. Batch adsorption study was carried out with variables like pH, adsorbent dose, initial dye concentration and time. The response surface methodology (RSM) was applied to design the experiments, model the process and optimize the variable. A 24 full factorial central composite design was successfully employed for experimental design and analysis of the results. The parameters pH, adsorbent dose, initial dye concentration, and time considered for this investigation play an important role in the adsorption studies of methylene blue dye removal. The experimental values were in good agreement with the model predicted values. The optimum values of pH, adsorbent dose, initial dye concentration and time are found to be 10, 2.1846 g/L, 50 mg/L and 63 min for complete removal of MB dye respectively

pH Sensitivity Estimation in Potentiometric Metal Oxide pH Sensors Using the Principle of Invariance

A numerically solvable engineering model has been proposed that predicts the sensitivity of metal oxide- (MOX-) based potentiometric pH sensors. The proposed model takes into account the microstructure and crystalline structure of the MOX material. The predicted pH sensitivities are consistent with experimental results with the difference below 6% across three MOX (RuO2, TiO2, and Ta2O5) analysed. The model distinguishes the performance of different MOX phases by the appropriate choice of surface hydroxyl site densities and dielectric constants, making it possible to estimate the performance of MOX electrodes fabricated through different high-temperature and low-temperature annealing methods. It further addresses the problem, cited by theoreticians, of independently determining the C1 inner Helmholtz capacitance parameter while applying the triple-layer model to pH sensors. This is done by varying the C1 capacitance parameter until an invariant pH sensitivity across different electrolyte ionic strengths is obtained. This invariance point identifies the C1 capacitance. The corresponding pH sensitivity is the characteristic sensitivity of MOX. The model has been applied across different types of metal oxides, namely, expensive platinum group oxides (RuO2) and cheaper nonplatinum group MOX (TiO2 and Ta2O5). High temperature annealed, RuO2 produced a high pH sensitivity of 59.1082 mV/pH, while TiO2 and Ta2O5 produced sub-Nernstian sensitivities of 30.0011 and 34.6144 mV/pH, respectively. Low temperature annealed, TiO2 and Ta2O5 produced Nernstian sensitivities of 59.1050 and 59.1081 mV/pH, respectively, illustrating the potential of using cheaper nonplatinum group MOx as alternative sensor electrode materials. Separately, the usefulness of relatively less investigated, cheap, and readily available MOX, viz. Al2O3, as the electrode material was analysed. Low-temperature-annealed Al2O3 with a Nernstian sensitivity of 59.1050 mV/pH can be considered as a potential electrode material. The proposed engineering model can be used as a preliminary prediction mechanism for choosing potentially cheaper alternative sensor electrode materials

Progress in the production of hydrogen energy from food waste: A bibliometric analysis

The exponential increase in food waste generation has prompted the scientific community to convert it into value-added resources. Hydrogen energy provides a sustainable option to fossil fuels due to its purity, high energy content, with no emissions other than water vapor. Combining the two aspects, a bibliometric analysis was performed for the conversion of food waste to hydrogen energy to evaluate the research trends based on literature in the Scopus database over the last two decades. The cluster analysis supported with the visualization tool aided in conducting a systematic study revealing growing themes and hot issues. The results showed a growing interest in the conversion of food waste to hydrogen energy research with the number of publications increasing by nearly 50 times in the last two decades. Comprehensive journals like the International Journal of Hydrogen Energy were most popular in publishing articles contributing to almost 30% in the research area. The country-wise analysis revealed that China accounted for more than 25% of the articles published followed by South Korea and India while the USA dominated in terms of the number of citations. Lastly, keyword cluster analysis revealed five major research hotspots for future discussion. The study concludes that further perspectives on fuel delivery, environmental impacts, and social acceptance could aid in positive developments in the biohydrogen energy industry. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Outcome of Miniperc Technique in Paediatric Age Group: A Prospective Interventional Study

Introduction: Reducing the Percutaneous Nephrolithotomy (PCNL) tract size in paediatric patients with renal stones reduces the morbidity associated with the procedure. Miniperc (Mini PCNL) is a modification of standard PCNL using small size instruments. Aim: To evaluate the postoperative outcome of Miniperc technique in the treatment of renal stones in paediatric age group. Materials and Methods: This was a prospective interventional study conducted at the Department of Urology, Govt. Mohan Kumaramangalam Medical College & Hospital, Salem, Tamil Nadu, India from January 2020 to January 2022. There were 25 patients of renal stone disease belonging to paediatric age group (<8 years), operated by a single surgeon with the Miniperc technique. For all the cases 14F-16F sheaths, 12 Fr Nephroscope and 8-9.5 Fr semirigid ureteroscope, pneumatic lithotripsy and 30-Watt Holmium laser as energy sources were used. Stone‑Free Rate (SFR), operative time, hospital stay, and complication rates were assessed. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 26.0. Results: The mean age of the children was 5.2±3.2 years and the average stone size was 1.9 cm. Mean operative time was 74 minutes. The mean hospital stay was 1.5 days. The overall SFR was 89.7%, (N=22) which increased after secondary procedures to 94.12% (N=23). Intraoperative bleeding was seen in 3 (12%) patients and postoperative fever in 4 (16%) patients. Conclusion: Miniperc is a promising and safe technique for paediatric renal stone disease management

Analysis on ψ-Hilfer Fractional Impulsive Differential Equations

In this manuscript, we establish the existence of results of fractional impulsive differential equations involving ψ-Hilfer fractional derivative and almost sectorial operators using Schauder fixed-point theorem. We discuss two cases, if the associated semigroup is compact and noncompact, respectively. We consider here the higher-dimensional system of integral equations. We present herewith new theoretical results, structural investigations, and new models and approaches. Some special cases of the results are discussed as well. Due to the nature of measurement of noncompactness theory, there exists a strong relationship between the sectorial operator and symmetry. When working on either of the concepts, it can be applied to the other one as well. Finally, a case study is presented to demonstrate the major theory