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Experimental Performance Evaluation of a Rechargeable Lithium-Air Battery With Hyper- Branched Polymer Electrolyte
No full textSynthesis of hyper branched polymer (HBP) based electrolyte has been examined in this study. A real world lithium-air battery cell was fabricated using the developed HBP electrolyte, oxygen permeable air cathode and lithium metal as anode material. Detailed synthesis procedures of hyper branched polymer electrolyte and the effect of different operation conditions on the real-world lithium-air battery cell were discussed in this paper. The fabricated battery cells were tested under dry air with 0.1mA∼0.2mA discharge current to determine the effect of different operation conditions such as carbon source, electrolyte types and cathode processes. It was found that different processes affect the battery cell performance significantly. We developed optimized battery cell materials upon taking into account the effect of different processes. Several battery cells were fabricated using the same optimized anode, cathode and electrolyte materials in order to determine the battery cells performance and reproducibility. Experimental results showed that the optimized battery cells were able to discharge over 55 hours at over 2.5V. It implies that the optimized battery cell can hold charge for more than two days at over 2.5V. It was also shown that the lithium-air battery cell can be reproduced without loss of performance with the optimized battery cell materials
Supercritical Impregnation of Walnut Husk Extract into Polyethylene Film
No full textOne of the biggest challenges in packaging products, specifically food products, is the need to inhibit microbial growth, spoilage, and the adverse effects those have. Active Packaging, such as those produced by impregnation of antioxidant compounds into films using supercritical fluids, have been demonstrated in other studies to increase shelf-life of packaged fruit and other goods. Supercritical fluids are fluids above their critical point, and exhibit high diffusivity, both liquid and gas like properties, and in the case of supercritical carbon dioxide, the ability to swell polymers. Due to this ability and a low critical temperature of 31 °C, supercritical carbon dioxide can be used to impregnate plant extracts into polymer films. In this study, antioxidant, polyphenolic compounds are extracted from the green husks of North American walnuts, and simultaneously, impregnated into low-density polyethylene (LDPE) films.Impregnation tests were carried out in a 500 mL, agitated, high-pressure reactor using supercritical carbon dioxide with a 15 mol-% ethanol modifier at 60 °C and constant walnut husk to ethanol mass ratio. The effects of varying pressure from 2400 to 3200 psi, and impregnation time from 1 to 3 hours was evaluated. After impregnation, film samples were characterized using infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), as well as other tests. FTIR shows that walnut husk extract was successfully impregnated into LDPE films. These results will be presented and compared against a control
Infusion of Walnut Husk into Polyethylene
No full textBlack walnuts, juglans nigra, are indigenous to eastern North America, and the nut is composed of the kernel, shell, and husk. In commercial production, the nuts are harvested from the ground and sold to processors that de-husk the walnut and the de-husked walnuts are then shipped for further processing. The green, or fresh, husk is commonly discarded. Green walnut husks contain a wealth of polyphenolic compounds, tannins, and other chemicals, and the husk exhibits antimicrobial and antioxidant properties. Walnut husks may also be used as a bio-herbicide. These antimicrobial compounds may be extracted from black walnut husk using supercritical carbon dioxide with an ethanol modifier, with the resulting extract exhibiting antioxidant and antimicrobial properties. Additionally, supercritical carbon dioxide can cause polymers to swell, thereby allowing polymers to be infused with chemicals while exposed to supercritical carbon dioxide. It will be presented that carbon dioxide and ethanol can be used in extracting chemicals, as determined by HPLC-MS analysis, from walnut husk while simultaneously infusing chemicals into polyethylene. The resulting extract showed antioxidant potential as measured by the total phenolic content (TPC) assay and antimicrobial properties. The treated polyethylene exhibited antimicrobial effects compared to an untreated control. The treated polyethylene was also analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) and compared against a control. Additionally the treated polyethylene was then heated to its melt temperature and its antimicrobial properties re-evaluated
Indicator 7 Response
No full textBased on information in the 2018 Institutional Report submitted to HLC, Indicator 7 - Weak Graduation/Persistence Rates Compared to Peers was triggered. This report submitted to HLC for staff review contains information pertaining to Indicator 7
8/1/2018: Statistical Methods for Data Science
No full textThis is a required course for candidates for the “Master of Science in Data Science” program. It provides necessary background in probability to study statistical analysis methods and modeling for data science
