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61.
Herein, a simple and rapid method is described for detection of l-ascorbic acid by ascorbate oxidase immobilized onto polycarbonate strip pre-activated by 1-fluoro-2-nitro-4-azidobenzene in photochemical reaction. Covalent attachment of ascorbate oxidase was confirmed by XPS studies. The immobilized-ascorbate oxidase shows higher pH, thermal and storage stability in comparison to free enzyme. 相似文献
62.
Rajesh Kumar Vishwakarma Uma Shanker Shivhare Saroj Kumar Nanda 《Food and Bioprocess Technology》2012,5(4):1364-1371
A study on the guar seeds (Cyamopsis tetragonoloba) was performed to investigate the effect of moisture content on the selected physical properties. Moisture contents of seeds
were varied from 5.2% to 25.0%, dry basis (d.b.). Seed geometric parameters, such as average length, width, thickness, geometric-mean
diameter, surface area, volume, increased but sphericity decreased with increase in moisture content. The 1,000-seed mass
increased linearly with moisture content. Bulk density of guar seeds decreased linearly when moisture content was raised from
5.2% to 25.0% d.b. On the other hand, true density decreased till moisture content was increased up to 20%. Further increase
in seed moisture resulted in increased true density, which has not been observed in other food grains. The porosity decreased
till seed 15.3% moisture and then increased with further addition of moisture. Angle of repose, coefficients of static friction
on three different surfaces (plywood, mild steel, and galvanized iron), and terminal velocity increased linearly with seed
moisture content. 相似文献
63.
Sujittra Chandarak Jaru Jutimoosik Athipong Bootchanont Muangjai Unruan Pongsakorn Jantaratana Shashank Priya Sutham Srilomsak Saroj Rujirawat Rattikorn Yimnirun 《Journal of Superconductivity and Novel Magnetism》2013,26(2):455-461
The novel Cu- and Mn-doped and Cu/Mn codoped 0.75BiFeO3–0.25BaTiO3 magnetoelectric ceramics were successfully prepared by a solid-state reaction method. The dielectric, ferroelectric, ferromagnetic, and magnetoelectric properties were determined and all the results suggested that Cu and Mn dopants occupied different B-site lattices in the 0.75BiFeO3–0.25BaTiO3 structure. To identify the preferential sites of Cu and Mn in the lattice, Synchrotron X-ray Absorption Spectroscopy (SXAS) measurements were carried out. A combination of both measured and simulated XAS results with a linear combination fitting (LCF) revealed that in Cu- and Mn-doped 0.75BiFeO3–0.25BaTiO3 ceramics both Mn and Cu substituted at Fe-site and Ti-site with slightly different proportion. On the other hand, both dopants were found to occupied different sites in Cu/Mn codoped 0.75BiFeO3–0.25BaTiO3 ceramics. 相似文献
64.
Pali Rosha Saroj Kumar Mohapatra Sunil Kumar Mahla Amit Dhir 《International Journal of Hydrogen Energy》2018,43(46):21246-21255
Catalytic dry reforming of biogas for hydrogen enrichment was studied over cerium oxide promoted nickel catalysts supported on titanium dioxide and aluminium oxide. The catalysts were prepared by wet impregnation method and characterized by H2-TPR, XRD, BET and FESEM techniques. Their catalytic performance in the biogas dry reforming reaction was studied at temperature ranges from 650 to 850 °C, with a CH4/CO2 ratio of 1.5:1. The H2-TPR results revealed that 11 wt % Ni impregnation on TiO2 support makes the catalyst with strong metal-support interaction which moderates the metal sintering. Also, the addition of CeO2 effectively improved the CH4 and CO2 conversions as well as H2 enrichment. At 850 °C, 11 wt % Ni/TiO2 catalyst leads to 70.5% CH4 conversion with 32.0% H2 enrichment, whereas, Ni0·11/Ce0.20 (Al2O3TiO2) yielded high CH4 conversion (84.9%) with 40.6% of H2 enrichment. No significant change in the activity of the catalyst was observed with 8.8 wt % of carbon deposited on the Ni0·11/Ce0.20 (Al2O3TiO2) catalyst, after 7 h of continuous reforming. Moreover, under combined (dry and oxidative) reforming of biogas, the stoichiometric H2/CO ratio (1.2) was observed at 0.47 O2/CH4 ratios with negligible carbon deposition. Thus, Ni0·11/Ce0.20 (Al2O3TiO2) catalyst exhibited better activity and selectivity with high catalyst stability at 850 °C. 相似文献
65.
Abstract—In this article, a firefly algorithm is proposed for load frequency control of multi-area power systems. Initially a two equal area non-reheat thermal system is considered and the optimum gains of the proportional integral/proportional integral derivative controller are optimized employing the firefly algorithm technique. The superiority of the proposed approach is demonstrated by comparing the results with some recently published techniques such as genetic algorithm, bacteria foraging optimization algorithm, differential evolution, particle swarm optimization, hybrid bacteria foraging optimization algorithm-particle swarm optimization, and Ziegler–Nichols-based controllers for the same interconnected power system. Further, the proposed approach is extended to a three-unequal-area thermal system considering generation rate constraint and governor dead-band. Investigations reveal on comparison that proportional integral derivative controller provides much better response compared to integral and proportional integral controllers. Additionally, robustness analysis is carried out by varying the operating load condition and time constants of speed governor, turbine, and inertia constant in the range of +50 to –50% from their nominal values as well as the size and position of step load perturbation to demonstrate the robustness of the proposed firefly algorithm optimized proportional integral derivative controller. 相似文献
66.
Saroj Rajthala Anjie Min Himalaya Parajuli Kala Chand Debnath Borghild Ljkjel Kristin Marie Hoven Arild Kvalheim Stein Lybak Evelyn Neppelberg Olav Karsten Vintermyr Anne Christine Johannessen Dipak Sapkota Daniela Elena Costea 《International journal of molecular sciences》2021,22(21)
Background: Knowledge on the role of miR changes in tumor stroma for cancer progression is limited. This study aimed to investigate the role of miR dysregulation in cancer-associated fibroblasts (CAFs) in oral squamous cell carcinoma (OSCC). Methodology: CAF and normal oral fibroblasts (NOFs) were isolated from biopsies of OSCC patients and healthy individuals after informed consent and grown in 3D collagen gels. Total RNA was extracted. Global miR expression was profiled using Illumina version 2 panels. The functional impact of altered miR-204 expression in fibroblasts on their phenotype and molecular profile was investigated using mimics and inhibitors of miR-204. Further, the impact of miR-204 expression in fibroblasts on invasion of adjacent OSCC cells was assessed in 3D-organotypic co-cultures. Results: Unsupervised hierarchical clustering for global miR expression resulted in separate clusters for CAF and NOF. SAM analysis identified differential expression of twelve miRs between CAF and NOF. Modulation of miR-204 expression did not affect fibroblast cell proliferation, but resulted in changes in the motility phenotype, expression of various motility-related molecules, and invasion of the adjacent OSCC cells. 3′ UTR miR target reporter assay showed ITGA11 to be a direct target of miR-204. Conclusions: This study identifies differentially expressed miRs in stromal fibroblasts of OSCC lesions compared with normal oral mucosa and it reveals that one of the significantly downregulated miRs in CAF, miR-204, has a tumor-suppressive function through inhibition of fibroblast migration by modulating the expression of several different molecules in addition to directly targeting ITGA11. 相似文献
67.
Flame temperature analysis of biodiesel blends and components 总被引:6,自引:0,他引:6
Meeting sustainable energy demand with minimum environmental impact is a major area of concern in the energy sector. Alternative fuels such as biodiesel, ethanol etc. have been quite promising for fulfilling both these aspects. While biodiesel reduces emissions of CO, life cycle CO2, SOx, volatile organic compounds (VOC) and particulate matter (PM) significantly, the propensity for the production of NOx is an important problem that requires extensive research. NOx emission from a direct-injection diesel engine is mainly due to formation of thermal NO that is described by Zeldovich mechanism. Thus, studying temperature profile during biodiesel combustion can provide useful insights to the formation and destruction of NOx. The main objective of this work is to investigate the effect of component methyl esters of biodiesel on open air flame temperature distribution and the effect of blending biodiesel with diesel and oxygenates (ethanol and methyl acetate) on open air flames. This objective was achieved by obtaining thermocouple measurements and thermal infrared imaging of local flame temperatures of wick-generated open air flames. A relationship between blend proportions and relative flame temperatures were obtained. In general, it was found that blending oxygenates such as ethanol and methyl acetate into petroleum diesel tended to increase the flame temperature in comparison with straight diesel fuel. The analyses of relative flame temperatures of different components of biodiesel were performed to evaluate the effect of unsaturation level and the hydrocarbon chain length on the flame temperature. It was found that the saturated methyl esters resulted in greater flame temperatures in comparison to unsaturated methyl esters. It was also revealed that shorter chained fatty acid methyl esters lead to higher flame temperatures as compared to its longer chained counterparts. 相似文献
68.
Presence of fully converted monoalkyl esters is the major requirement in quality biodiesel. Due to high associated costs with testing and widespread production of biodiesel not only in commercial scale but also in small scale, there is a high propensity of substandard biodiesel entering the market and being used in compression ignition engines. Due to this reason, it is important to understand how low grade biodiesel with a lower methyl ester conversion affects the parameters of quality standards and as a result, engine performance and durability. In this paper, the performance of fatty acid methyl esters with different proportions of unconverted triglycerides has been evaluated. The study has comprehensively evaluated the effect of unconverted triglycerides on flash point, water and sediment, kinematic viscosity, sulfur content, sulfated ash, copper strip corrosion, cetane number, cloud point, carbon residue, acid number, free glycerin, total glycerin, phosphorus content and distillation temperature. 相似文献
69.
Optimal regulation of hyperbolic systems in the presence of unknown exogenous and initial disturbances is considered. Necessary conditions for determining the optimal control that tracks a desired trajectory in the presence of disturbances are developed. These necessary conditions have the form of a twopoint boundary-value problem along with certain equality and inequality conditions. The results also characterize the worst possible disturbances that are accommodated by the optimum controller without any serious performance degradation. Numerical results on the control of a vibrating beam are presented. 相似文献
70.