PERFORMANCE OF Ni/CEO2/YSZ SOFC ANODES WITH CARBONACEOUS FUELS

This study explores the impact of ceria incorporation into Ni/YSZ cermet anode support layers on the performance of button-cell solid oxide fuel cells operating with syngas and n-butane/steam fuel feeds. Ceria is incorporated into the porous anode support by co-firing ceria powders with NiO, YSZ, and graphite pore formers. Comparison of the performance with and without the co-fired ceria indicated improvements for operation with doped ceria for both syngas (by almost 20% higher power density) and direct n-butane/steam feeds (by over 25% higher power density). For initial cell performance, ceria addition to the support layer offered improved performance at high current densities with syngas suggesting that ceria enhanced water-gas-shift reactions, thereby increasing H2 availability for more effective electrochemical oxidation in the functional layer. For longer-term testing with direct-butane feeds, ceria doped cells not only showed better performance, but also indicated suppression of carbon deposition thus improving long term operability. Ex situ characterization of the ceria-doped anodes using SEM and Raman spectroscopy indicated that ceria addition helped the anodes maintain their structural integrity. To better understand the experiments, a previous through-the-MEA 1-D model has been updated and used with C-H-O microkinetics for Ni/YSZ anodes to characterize the experimentally observed cell performance. The model was enhanced by developing a leakage mechanism to account for leakage through the electrolyte and by incorporating non-isothermal effects to account for temperature gradients due to endothermic internal reforming and exothermic oxidation within the anode layers. Studies with internal methane reforming in a Ni/YSZ anode showed that the non-isothermal effects in 1-D button cell experiments are very small. This through-the-MEA model was used to fit experimental data and provided a basis for assessing key micro-structural parameters for the Ni/YSZ cells tested in this study. The model fits with syngas at various compositions provided a basis for assessing the most sensitive micro-structural parameters on the fuel cell performance such as anode support layer porosity and tortuosity

Numerical modeling of the failure mechanisms in Si thin film anode for Li-ion batteries

In recent times, the demand for the storage of electrical energy has grown rapidly for both static applications and the portable electronics enforcing the substantial improvement in battery systems, and Li-ion batteries have been proven to have maximum energy storage density in all rechargeable batteries. However, major breakthroughs are required to consummate the requirement of higher energy density with lower cost to penetrate new markets. Graphite anode having limited capacity has become a bottle neck in the process of developing next generation batteries and can be replaced by higher capacity metals such as Silicon. In the present study we are focusing on the mechanical behavior of the Si-thin film anode under various operating conditions. A numerical model is developed to simulate the intercalation induced stress and the failure mechanism of the complex anode structure. Effect of the various physical phenomena such as diffusion induced stress, plasticity and the crack propagation are investigated to predict better performance parameters for improved design

Design and Synthesis of Some Heterocycles of Medicinal Interest

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Retinal nerve fiber layer thickness analysis in normal, ocular hypertensive, and primary open angle glaucoma: an optical coherence tomography study

Background: To correlate the findings of optical coherence tomography (OCT) evaluation of retinal nerve fiber layer (RNFL) thickness in primary open angle glaucoma, ocular hypertensive and normal eyes.Methods: A 34 consecutive normal, 26 consecutive ocular hypertensives and 40 consecutive glaucomatous eyes underwent a complete ophthalmic examination, including applanation tonometry, disc evaluation, gonioscopy and perimetry. Thickness of the RNFL around the optic disc was determined with 3.4 mm diameter-wide 3D 2000 TOPCON OCT. Average and segmental RNFL thickness values were compared among all groups.Results: Of the 100 eyes enrolled, the mean RNFL thickness was significantly less in glaucomatous eyes (83.165±15.938) than in normal’s (102.42±15.2) and ocular hypertensive’s (100.45±7.38). RNFL, average thicknesses in all four quadrants in POAG patients were significantly decreased compared with the OHT and the control groups.Conclusions: RNFL measurement with SD-OCT could provide important information for detection of early stages of glaucoma. (pre-perimetric glaucoma) as well as help in evaluating progression of glaucoma

Evaluation of prescription pattern and quality of life in postmenopausal osteoporosis: a cross sectional study

Background: Osteoporosis (OP) is a silently progressing metabolic bone disease that results in loss of mineralized bone and subsequent fractures with minor trauma. Fracture related pain and physical inability to perform activities of daily living can lead to psychological consequences that impair Quality of Life (QoF). However, much less is known about Indian scenario. Hence, our study becomes imperative. Aim of this study to the drug utilization pattern and to analyze Quality of life of postmenopausal women suffering from osteoporosis.Methods: An analytical cross-sectional study was done on 91 post-menopausal osteoporotic women. Drug utilization pattern was evaluated. Pre-validated QUALEFFO-31 questionnaire was administered to each patient to record patient’s perceived QoL. Scores were calculated according to the algorithm. Higher scores indicated poor QoL. The collected data was analyzed with SPSS software (version 23)and p value ≤0.05 was considered as statistically significant.Results: The mean age group of presenting patients was 56.2±6.6 years. All the patients received Calcium and vitamin D supplements and non-steroidal anti-inflammatory drugs for pain relief. But only 33% of the patients received any one of the bisphosphonates (BP). For analysis, patients were grouped into Group-1(n=60) who did not and Group-2 (n=31) who did receive a BP. QOL analysis showed that pain domain was affected the most. Also, patients in Group 2 reported worse score in all the domains in comparison to Group 1 (P<0.05). It is likely that BP might need more time to show considerable effect or because it was added only to those patients who already had more complaints and could afford the high cost.Conclusion: BP in spite of being the drug of choice for OP is used less commonly in India. OP causes pain and physical debilitation with detrimental effect on mental health. Longer duration prospective studies are needed to study the association of QoL and use of BP in OP patients