1,967 research outputs found

    Synthesis of Green Hydrocarbons Using the AIR TO FUELS™ Technology

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    Our AIR TO FUELS™ project is based off a process designed by Carbon Engineering by the same name which seeks to synthesize liquid fuels from capture carbon dioxide captured from the atmosphere. The need for reduced greenhouse gases in our atmosphere is more urgent than ever and becoming more dire by the day. Still, our society’s reliance on liquid fuels like gasoline, diesel, and jet fuel is deeply rooted in our infrastructure and certainly not changing quickly or soon. The AIR TO FUELS™ process seeks to tackle both of these problems by taking carbon dioxide out of the atmosphere in order to produce 2000 bbl/day of liquid fuels that work with our vast existing petroleum-based infrastructure. This AIR TO FUELS™ plant can be easily segmented into four different portions of the process, each accomplishing an integral step in the production of synthetic fuels. Perhaps the most important is the carbon capture step, making use of the patented Direct Air Capture technology to strip carbon dioxide from the air and purify it to the level needed for the production of syngas via the water-gas shift reaction. Syngas is then converted to alkanes using the nearly century old Fischer-Tropsch process and these alkanes are purified with a network of flash drums and a distillation column. Products generated from this final step are heavy alkanes (waxes and lubricants) to be sold, light gases to be burned in lieu of fuel gas in several of the gas-fired heaters used in the plant, and pure gasoline and diesel range alkanes, to be sold to refiners who will then blend these alkanes into usable fuels. Due to this final step necessitating the cooperation of oil refineries, it is germane to locate the AIR TO FUELS™ plant near large concentrations of these corporations, which indicates that the Gulf Coast of Texas is a suitable choice. This agrees with other factors such as high humidity, subsidies for renewable energy, and large swathes of available land, and as such, the area near the city of Corpus Christi, Texas is considered ideal. While the science and engineering behind our AIR TO FUELS™ process design are solid, its economic prospects are not. We hope to sell our product as green synthetic crude oil at 72/bbl,charginga1.2xpremiumforbothitscleanness(freeofheavymetals,NOx,andSOx)andgreenness.Thetotalcapitalinvestmentofourprojectexceeds72/bbl, charging a 1.2x premium for both its cleanness (free of heavy metals, NOx, and SOx) and greenness. The total capital investment of our project exceeds 2.2 billion, including 812millioninsolarpanelstoeaseour500MWelectricitycosts,812 million in solar panels to ease our 500 MW electricity costs, 378.5 million in electrolyzers to generate hydrogen, 300millionincatalystsandnormalchemicalprocessingequipment,and300 million in catalysts and normal chemical processing equipment, and 6.8 million in high capacity fans for our carbon capture system. On top of the massive capital investment, the daily operating costs of our design far outweigh our daily revenue, guaranteeing our project to be unprofitable. These daily costs come mostly from the utilities - the replenishment of our CO2 absorbing solution and its salts costs 86.74/bbl,andthecostoftheremainingutilities(coolingwater,steam,refrigerant,etc.)is86.74/bbl, and the cost of the remaining utilities (cooling water, steam, refrigerant, etc.) is 55.75/bbl. We hope that the ongoing development of solar panel and electrolyzer technologies alongside improvements in the efficiency of our design could one day make our AIR TO FUELS™ process profitable

    Laser speckle imaging in the spatial frequency domain

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    Laser Speckle Imaging (LSI) images interference patterns produced by coherent addition of scattered laser light to map subsurface tissue perfusion. However, the effect of longer path length photons is typically unknown and poses a limitation towards absolute quantification. In this work, LSI is integrated with spatial frequency domain imaging (SFDI) to suppress multiple scattering and absorption effects. First, depth sensitive speckle contrast is shown in phantoms by separating a deep source (4 mm) from a shallow source (2 mm) of speckle contrast by using a high spatial frequency of illumination (0.24 mm−1). We develop an SFD adapted correlation diffusion model and show that with high frequency (0.24 mm−1) illumination, doubling of absorption contrast results in only a 1% change in speckle contrast versus 25% change using a planar unmodulated (0 mm−1) illumination. Similar absorption change is mimicked in vivo imaging a finger occlusion and the relative speckle contrast change from baseline is 10% at 0.26 mm−1 versus 60% at 0 mm−1 during a finger occlusion. These results underscore the importance of path length and optical properties in determining speckle contrast. They provide an integrated approach for simultaneous mapping of blood flow (speckle contrast) and oxygenation (optical properties) which can be used to inform tissue metabolism

    Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging

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    We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI

    Descriptions of Scottish Priority Marine Features (PMFs).

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    Background The seas around Scotland are rich and diverse – Scotland’s position at the edge of the continental shelf, the long coastline, large area of sea and the mixing of warm and coldwater currents combine to make its waters a special place for marine wildlife and habitats. Scotland has over 18,000 km of coastline and its inshore and offshore areas are among the largest of any EU country, representing 13% of all European seas. Scotland’s seas are of outstanding scenic, historical and cultural value and are part of the national identity at home and abroad. The Marine (Scotland) Act 2010 and the UK Marine and Coastal Access Act 2009 include new powers and duties to ensure that our seas are managed sustainably for future generations, integrating the economic growth of marine industries with the need to protect these assets. Measures to conserve Scotland’s marine natural heritage are based on a three pillar approach, with action at the wider seas level (e.g. marine planning or sectoral controls); specific species conservation measures (e.g. improved protection for seals); and through site protection measures - the identification of new Marine Protected Areas (MPAs). To help target action under each of the three pillars, Scottish Natural Heritage (SNH) and the Joint Nature Conservation Committee (JNCC) have generated a focused list of habitats and species of priority conservation importance - the Priority Marine Features (PMFs). The aim of the current study was to produce a descriptive catalogue of the Scottish PMFs (including component habitats and species where appropriate) to serve as a reference for future nature conservation action. Whilst derived from available existing accounts, the succinct 1-page descriptions are written from a Scottish perspective, refining, but clearly linking to more generic UK, EC or OSPAR (Oslo and Paris Commission) commentary. Available information on the geographic distribution of the features was collated as part of the project and a summary map is provided in each description. Main findings This project has generated a descriptive catalogue of the 81 PMFs that have been identified in the seas around Scotland (out to the limit of the UK continental shelf). The list comprises 26 broad habitats (e.g. burrowed mud), seven low or limited mobility species (e.g. ocean quahog) and 48 mobile species, including fish (e.g. blue ling) and marine mammals (e.g. minke whale). Information on the distribution of the PMFs was collated within a Geographic Information System (GIS). This is the first time that data about such a diverse range of Scottish marine nature conservation interests have been compiled within a single repository. These data have and will be used in conjunction with other contextual base-mapping to inform the development of nature conservation advice and commentary (e.g. in the production of the Scotland’s Marine Atlas - Baxter et al., 2011). The feature distribution mapping used in the production of this report is being made available to view online via the National Marine Plan Interactive web portal (NMPi - http://www.gov.scot/Topics/marine/seamanagement/nmpihome). As new or refined data on Scottish PMFs become available, these will be fed into updates to the project geodatabase and NMPi

    Complete Genome Sequence of the N2-Fixing Broad Host Range Endophyte Klebsiella pneumoniae 342 and Virulence Predictions Verified in Mice

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    We report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, Klebsiella pneumoniae 342. Although K. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world), while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. Genomic analysis examined K. pneumoniae 342 for the presence of previously identified genes from other bacteria involved in colonization of, or growth in, plants. From this set, approximately one-third were identified in K. pneumoniae 342, suggesting additional factors most likely contribute to its endophytic lifestyle. Comparative genome analyses were used to provide new insights into this question. Results included the identification of metabolic pathways and other features devoted to processing plant-derived cellulosic and aromatic compounds, and a robust complement of transport genes (15.4%), one of the highest percentages in bacterial genomes sequenced. Although virulence and antibiotic resistance genes were predicted, experiments conducted using mouse models showed pathogenicity to be attenuated in this strain. Comparative genomic analyses with the presumed human pathogen K. pneumoniae MGH78578 revealed that MGH78578 apparently cannot fix nitrogen, and the distribution of genes essential to surface attachment, secretion, transport, and regulation and signaling varied between each genome, which may indicate critical divergences between the strains that influence their preferred host ranges and lifestyles (endophytic plant associations for K. pneumoniae 342 and presumably human pathogenesis for MGH78578). Little genome information is available concerning endophytic bacteria. The K. pneumoniae 342 genome will drive new research into this less-understood, but important category of bacterial-plant host relationships, which could ultimately enhance growth and nutrition of important agricultural crops and development of plant-derived products and biofuels

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
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