Optical Emission Spectroscopy for Plasma Etch Endpoint Detection

Optical Emission Spectroscopy was implemented for determining the endpoint of film removal through detecting shifts in plasma emission intensity during an etch process. A preliminary procedure has been developed for detecting endpoint with the factory nitride and oxide etch processes at RIT. In conjunction with the development of an endpoint process, the minimum sensitivity for the OES endpoint system was investigated. A minimum of 0.5% exposed nitride versus resist area is required for accurately detecting endpoint on Nitride, while 5% open area is necessary for Oxide

Reevaluation of Wolfcampian Cyclothems in Northeastern Kansas: Significance of Subaerial Exposure and Flooding Surfaces

Ten cyclothems from the Wolfcampian of northeastern Kansas, including parts of the Council Grove and Chase Groups, were examined in detail with particular attention to discontinuity surfaces and paleosol development. These cyclothems are shown to be bounded by major discontinuities, or sequence boundaries, where marine limestones abruptly overlie paleosol profiles. Occurring within these cyclothemic sequences are prominent meter-scale cycles that are bounded by flooding surfaces, many of which overlie facies exhibiting evidence of subaerial exposure. They are developed within both the marine carbonate and shale intervals and variegated mudstone intervals of the cyclothems. These meter-scale cycles show a consistent carbonate-to-clastic pattern regardless of their stratigraphic position or component facies. Climate fluctuations within a generally monsoonal environment are determined to be the most likely forcing mechanism for the meter-scale cycles, with wetter climate phases resulting in the increased influx of terrigenous clastic sediment and drier climate phases favoring carbonate precipitation. Evidence of climate change at the scale of the cyclothemic sequences is also recognized in the studied interval. Cycles at both scales indicate that relative sea-level rise was associated with increasingly arid conditions and that sea-level fall was associated with an intensification of seasonal rainfall

Willingness to Pay for a Potential Insurance Policy: Case Study of Trout Aquaculture

Using trout producer survey data and the contingent valuation method, we estimate willing-ness to pay for a potential insurance policy. The survey was conducted in 2005 across the United States; 268 producers completed the survey instrument, resulting in a response rate of 81 percent. Design of the contingent valuation method takes into account two coverage levels and four premium rates. Using standard willingness-to-pay techniques, we assess the premium rate that producers with varying practices and regions are willing to pay for two different cov-erage levels of insurance. In general, trout producers appear willing to pay premium rates of 2 to 11 percent for these coverage levels.willingness to pay, subjective elicitation and survey data, aquaculture trout insurance, Livestock Production/Industries, Risk and Uncertainty,

Visualization of diffusion limited antimicrobial peptide attack on supported lipid membranes

Understanding the mechanism of action of antimicrobial peptides (AMP) is fundamental to the development and design of peptide based antimicrobials. Utilizing fast-scan atomic force microscopy (AFM) we detail the attack of an AMP on both prototypical prokaryotic (DOPC:DOPG) and eukaryotic (DOPC:DOPE) model lipid membranes on the nanoscale and in real time. Previously shown to have a favourable therapeutic index, we study Smp43, an AMP with a helical-hinge-helical topology isolated from the venom of the North African scorpion Scorpio maurus palmatus. We observe the dynamic formation of highly branched defects being supported by 2D diffusion models and further experimental data from liposome leakage assays and quartz crystal microbalance-dissipation (QCM-D) analysis, we propose that Smp43 disrupts these membranes via a common mechanism, which we have termed ‘diffusion limited disruption’ that encompasses elements of both the carpet model and the expanding pore mechanism

HYBRID MEMBRANE-PSA SYSTEM FOR SEPARATING OXYGEN FROMAR

A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc...) and represents a significant advance compared to current technologies

Identification and crystallisation of a heat- and protease-stable fragment of the bacteriophage T4 short tail fibre

Irreversible binding of Teven bacteriophages to Escherichia coli is mediated by the short tail fibres, which serve as inextensible stays during DNA injection. Short tail fibres are exceptionally stable elongated trimers of gene product 12 (gp12), a 56 kDa protein. The Nterminal region of gp12 is important for phage attachment, the central region forms a long shaft, while a Cterminal globular region is implicated in binding to the bacterial lipopolysaccharide core. When gp12 was treated with stoichiometric amounts of trypsin or chymotrypsin at 37 C, an Nterminally shortened fragment of 52 kDa resulted. If the protein was incubated at 56 C before trypsin treatment at 37 C, we obtained a stable trimeric fragment of 3 33 kDa lacking residues from both the N and Ctermini. Apparently, the protein unfolds partially at 56 C, thereby exposing proteasesensitive sites in the Cterminal region and extra sites in the Nterminal region. Welldiffracting crystals of this fragment could be grown. Our results indicate that gp12 carries a stable central region, consisting of the Cterminal part of the shaft and the attached Nterminal half of the globular region. Implications for structure determination of the gp12 protein and its folding are discussed