Microwave Spectroscopy

Contains reports on five research projects.United States Army Signal Corps (Contract DA36-039-sc-74895

Microwave Spectroscopy

Contains reports on three research projects

Performance of a megawatt-scale grid-connected solar photovoltaic power plant in Kolar District in Karnataka

A megawatt scale grid-connected photovoltaic power plant was commissioned on 27 December 2009 in Yalesandra in Kolar district in Karnataka. The Yalesandra plant is one among more than 20 such Megawatt size solar power plants in India during the past few years. The performance of this plant during its first year of operation has been discussed. The total electrical energy generated by the Yelasandra plant during 2010 was 3.34 million kWh. Although the performance of photovoltaic modules was good, there were problems associated with the inverters which led to reduction in energy generation. The impact of temperature variation of modules on their performance has been highlighted

Microwave Spectroscopy

Contains reports on five research projects

Dipeptidyl-peptidase-4 inhibitors and pancreatic cancer: a cohort study

Aims—Dipeptidyl-peptidase-4 inhibitors (DPP-4i) have been implicated with an increased pancreatic cancer risk. We therefore compared pancreatic cancer incidence and diagnostic work-up among initiators of DPP-4i versus sulfonylureas (SU) and thiazolidinediones (TZD). Methods—Medicare claims data were examined in a new-user active-comparator cohort study. Patients >65 years with no prescriptions for DPP-4i, SU or TZD at baseline were included if they had at least two claims for the same drug within 180 days. Using an as-treated approach and propensity score-adjusted Cox models, we estimated hazard ratios (HR) and 95% confidence intervals (CI) for pancreatic cancer. Diagnostic work-up was compared using risk ratios (RR). RESULTS—In the DPP-4i vs SU comparison, there were 18,179 DPP4i initiators of which 26 developed pancreatic cancer (follow-up time interquartile range 5–18 months). In the DPP-4i vs TZD comparison there were 29,366 DPP-4i initiators and 52 developed pancreatic cancer. The hazard of pancreatic cancer with DPP-4i was lower relative to SU (HR=0.6, CI 0.4–0.9) and similar to TZD (HR=1.0, CI 0.7–1.4). Excluding first 6 months of follow-up to reduce the potential for reverse causality did not alter results. Probability of diagnostic work-up post-initiation among DPP-4i initiators (79.3%) was similar to TZD (74.1%) (RR=1.06, CI 1.05–1.07) and SU (74.6%) (RR=1.06, CI1.05–1.07). The probability of diagnostic workup pre-index was ~80% for all cohorts. Conclusion—Though limited by sample size and the observed duration of treatment in the US, our well-controlled population based study suggests no increased short-term pancreatic cancer risk with DPP-4i relative to SU or TZD

Alcohol dehydrogenase and invertase activities in ethanol tolerant yeasts

Two ethanol tolerant yeast isolates of Saccharomyces cerevisiae Y-10 and Saccharomyces cerevisiae Y-7 were compared for their invertase (EC 3.2.1.26, β-fructofuranoside fructohydrolase) and alcohol dehydrogenase (ADH, EC 1.1.1.1, alcohol:NAD oxidoreductase) activities as well as ethanol productivity. The isolates showed significantly higher ethanol productivities compared to the standard strain Saccharomyces uvarum and other yeast strains tested. The alcohol dehydrogenase activity was 40–100% higher in the isolates than S. uvarum and the percentage change varied depending on the growth conditions. However, this was not true for invertase activity. Both the isolates showed a similar ADH isozyme pattern in contrast to S. uvarum. The results suggested that a better correlation between ADH activity and ethanol productivity could be drawn only after extensive studies on the kinetic parameters of the individual isozymes

Microwave Spectroscopy

Contains reports on five research projects.United States Army Signal Corps (Contract DA36-039-sc-87376

Radio-Frequency Spectroscopy

Contains reports on four research projects

Radio-Frequency Spectroscopy

Contains reports on three research projects

Ultrathin 2 nm gold as ideal impedance-matched absorber for infrared light

Thermal detectors are a cornerstone of infrared (IR) and terahertz (THz) technology due to their broad spectral range. These detectors call for suitable broad spectral absorbers with minimalthermal mass. Often this is realized by plasmonic absorbers, which ensure a high absorptivity butonly for a narrow spectral band. Alternativly, a common approach is based on impedance-matching the sheet resistance of a thin metallic film to half the free-space impedance. Thereby, it is possible to achieve a wavelength-independent absorptivity of up to 50 %, depending on the dielectric properties of the underlying substrate. However, existing absorber films typicallyrequire a thickness of the order of tens of nanometers, such as titanium nitride (14 nm), whichcan significantly deteriorate the response of a thermal transducers. Here, we present the application of ultrathin gold (2 nm) on top of a 1.2 nm copper oxide seed layer as an effective IR absorber. An almost wavelength-independent and long-time stable absorptivity of 47(3) %, ranging from 2 $\mu$m to 20 $\mu$m, could be obtained and is further discussed. The presented gold thin-film represents analmost ideal impedance-matched IR absorber that allows a significant improvement of state-of-the-art thermal detector technology