The development of the Arrhenius equation

Abstract-Silicon carbide as an emerging technology offers potential benefits compared with the currently used silicon. One of these advantages is higher efficiency. If this is targeted, reducing the on-state losses is a possibility to achieve it. Parallel-connecting devices decrease the on-state resistance and therefore reduce the losses. Furthermore, increasing the amount of components such as parallel connection of devices introduces an undesired tradeoff between efficiency and reliability, since an increased component count increases the probability of failure. A reliability analysis has been performed on a three-phase inverter rated at 312 kVA, using parallel-connected power modules. This analysis shows that the gate voltage stress has a high impact on the reliability of the complete system. Decreasing the positive gate-source voltage could, therefore, increase the reliability of the system approximately three times without affecting the efficiency significantly. Moreover, adding redundancy in the system could also increase the mean time to failure by approximately five times.

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“…Using Arrhenius relation [62], the acceleration factor which results from operating a device at an elevated temperature…”

Section: Discussionmentioning

confidence: 99%

Reliability Analysis of a High-Efficiency SiC Three-Phase Inverter

Colmenares

Sadik

Hilber

et al. 2016

IEEE J. Emerg. Sel. Topics Power Electron.

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“…The aquifer in this study was a steady 14.7 uC over the course of this study. Assuming the Arrhenius principle applies to the biodegradation kinetics, which states that for every 10 uC increase there is an approximate doubling of the reaction rate (Laidler, 1984), the half-life of benzene and toluene in situ should be closer to 1.5 to 3 days. By comparison, under anaerobic conditions, the benzene and toluene had laboratory halflives of 23 to 26 days, which should be closer to 50 days in the natural anaerobic aquifer environment.…”

Section: Discussionmentioning

confidence: 99%

Adaptations of Indiginous Bacteria to Fuel Contamination in Karst Aquifers in South-Central Kentucky

Byl¹,

Metge²,

Agymang³

et al. 2014

JCKS

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Abstract:The karst aquifer systems in southern Kentucky can be dynamic and quick to change. Microorganisms that live in these unpredictable aquifers are constantly faced with environmental changes. Their survival depends upon adaptations to changes in water chemistry, taking advantage of positive stimuli and avoiding negative environmental conditions. The U.S. Geological Survey conducted a study in 2001 to determine the capability of bacteria to adapt in two distinct regions of water quality in a karst aquifer, an area of clean, oxygenated groundwater and an area where the groundwater was oxygen depleted and contaminated by jet fuel. Water samples containing bacteria were collected from one clean well and two jet fuel contaminated wells in a conduit-dominated karst aquifer. Bacterial concentrations, enumerated through direct count, ranged from 500,000 to 2.7 million bacteria per mL in the clean portion of the aquifer, and 200,000 to 3.2 million bacteria per mL in the contaminated portion of the aquifer over a twelve month period. Bacteria from the clean well ranged in size from 0.2 to 2.5 mm, whereas bacteria from one fuel-contaminated well were generally larger, ranging in size from 0.2 to 3.9 mm. Also, bacteria collected from the clean well had a higher density and, consequently, were more inclined to sink than bacteria collected from contaminated wells. Bacteria collected from the clean portion of the karst aquifer were predominantly (,95%) Gram-negative and more likely to have flagella present than bacteria collected from the contaminated wells, which included a substantial fraction (,30%) of Gram-positive varieties. The ability of the bacteria from the clean portion of the karst aquifer to biodegrade benzene and toluene was studied under aerobic and anaerobic conditions in laboratory microcosms. The rate of fuel biodegradation in laboratory studies was approximately 50 times faster under aerobic conditions as compared to anaerobic, sulfur-reducing conditions. The optimum pH for fuel biodegradation ranged from 6 to 7. These findings suggest that bacteria have adapted to water-saturated karst systems with a variety of active and passive transport mechanisms.

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“…Possible reasons for the higher stability of microencapsulated lipids are even dispersion of the HMFS in the wall material through the high speed shear emulsification, and the rapid atomization of the core material solution by spray drying at high temperature air flow, and the solidified wall material that protects the core material. According to the Arrhenius empirical formula, the shelf life of microcapsules is at least 24 months, which is significantly longer than that of un-capsulated lipids 38 . To conclude, microcapsule of HMFS protects it against spontaneous oxidation and increases its shelf life.…”

Section: Storage Stability Analysismentioning

confidence: 99%