4,287 research outputs found

    Green Gasification Technology for Wet Biomass

    Get PDF
    The world now is facing two energy related threats which are lack of sustainable, secure and affordable energy supplies and the environmental damage acquired in producing and consuming ever-increasing amount of energy. In the first decade of the twenty-first century, increasing energy prices reminds us that an affordable energy plays an important role in economic growth and human development. To overcome the abovementioned problem, we cannot continue much longer to consume finite reserves of fossil fuels, the use of which contributes to global warming. Preferably, the world should move towards more sustainable energy sources such as wind energy, solar energy and biomass. However, the abovementioned challenges may not be met solely by introduction of sustainable energy forms. We also need to use energy more efficiently. Developing and introducing more efficient energy conversion technologies is therefore important, for fossil fuels as well as renewable fuels. This assignment addresses the question how biomass may be used more efficiently and economically than it is being used today. Wider use of biomass, a clean and renewable feedstock may extend the lifetime of our fossil fuels resources and alleviate global warming problems. Another advantage of using of biomass as a source of energy is to make developed countries less interdependent on oil-exporting countries, and thereby reduce political tension. Furthermore, the economies of agricultural regions growing energy crops benefit as new jobs are created.Keywords: energy, gasification, sustainable, wet biomas

    A millimeter-wave antireflection coating for cryogenic silicon lenses

    Get PDF
    We have developed and tested an antireflection (AR) coating method for silicon lenses at cryogenic temperatures and millimeter wavelengths. Our particular application is a measurement of the cosmic microwave background. The coating consists of machined pieces of Cirlex glued to the silicon. The measured reflection from an AR coated flat piece is less than 1.5% at the design wavelength. The coating has been applied to flats and lenses and has survived multiple thermal cycles from 300 to 4 K. We present the manufacturing method, the material properties, the tests performed, and estimates of the loss that can be achieved in practical lenses

    Multidisciplinary Development of Autonomous Underwater Vehicle Fleet

    Get PDF
    Eco-Dolphin – Cooperative Fleet for Surveillance Mission SIAM, Society for Industrial & Applied Mathematics, members have been working for two years on the design, construction and testing of three highly integrated and streamlined autonomous underwater vehicles called Eco-Dolphins. This project is being developed at Embry-Riddle Aeronautical University’s Daytona Beach campus. The Leverage lab is used to create detailed mathematical models and conduct preliminary research for both electrical and mechanical systems. The campus Composites lab is used for the fabrication of structural and aesthetic components used by the high adaptable platform. The Autonomous Underwater Vehicle testing is conducted in the Universities Nonlinear Waves lab. The first phase of design, production and assembly of the yellow Eco-Dolphin prototype has been done in twelve months. The design includes an internal attitude control system, combined with internal propulsion from brushless direct current thrusters, thus allowing the vehicle to ascend and descend. The Eco-Dolphins promise is to be a unique, highly optimized and a competitive underwater vehicle fleet. The team has also successfully completed the second phase of the program, which involved tracking the Eco-Dolphins while submerged underwater. Work has been conducted to add a GPS system for surface tracking. Converting the acoustic system from tethered to wireless to make the ground station more robust. The Eco-Dolphin is configured with recently developed control system software that utilizes a relay combination of Wireless, Sonar and GPS radio wave communication. The current progress on the blue Eco-dolphin will be completed by the summer of 2014, for testing in littoral waters of central Florida. Through the addition of three sequential (yellow, blue, red) vehicles, therefore allows for better position and orientation data to be sent to the teams buoy network. The three vehicles, three buoy communication structure, multiply the data points collected for surveillance and underwater mapping purposes. This additional complexity improves the reliability and increases the application of the product through error elimination software. The team gives hands on research experience to SIAM members through applied mathematics. The outcome of the research goals, results in the application of many fields of study beyond mathematics. When combined the fleet can cooperatively fulfill multitask missions, advanced surveillance and environmental monitoring can be conducted. This opportunity opens the way for better balance between sustainable developments of the coastline

    Synergistic co-cultivation of activated sludge and microalgae in enhancing lipid production and N-laden wastewater treatment

    Get PDF
    The influence of inoculation ratios of activated sludge and microalgae were investigated in this study in the aspects of biomass yield, lipid yield and total nitrogen (TN) removal efficiency. It was observed that mixed culture of activated sludge/microalgae with the ratio 1:1 and 1:0.75 achieved a maximum lipid production up to 0.144 g/L and 0.133 g/L as compared with microalgae culture alone, which was only 0.081 g/L. The highest total nitrogen (TN) removal was observed with 1:1 and 1:0.75 ratios of activated sludge/microalgae cultures ranging from 96.3-96.9% removal efficiency, which was an improvement of about 90% removal efficiency compared to the activated sludge culture (6.25±0.08%). The flocculation efficiency was generally improved in mixed cultures of activated sludge andmicroalgae in comparison with only activated sludge culture and microalgae culture alone.Keywords: activated sludge; microalgae; co-cultivation; lipid; nitrogen removal

    MICROFRACTURE OF HUMAN THORACOLUMBAR VERTEBRAL BODY UNDER FATIGUE LOADING

    Get PDF
    The purpose of this study was to investigate the relationship between lumbar vertebral microfracture and fatigue loading on young human spine under physiological cyclic compression loads. Thirty-three thoracolumbar vertebrae (T12 to L4) were obtained from 7 adult Chinese male cadavers. They were randomly divided into 5 groups. Cyclical compression was performed for 20,000 cycles with 2 Hz. Load magnitude was determined respectively as 10%, 20% and 30% of the ultimate compressive load. Four cylindrical sections were obtained from each vertebra and the cross-sectional slides were made. The histomorphometry was used to determine microfracture densitiy and distribution. No fracture was detected in the radiographs of groups III, IV and V after fatigue load. Microfracture density in the cyclic compression group increased from 0.46 #/mm2 in Group III to 0.66 #/mm2 (Group IV) and 0.94 #/mm2 (Group V) under different loading levels (). These results provide evidence for the existence of microfractures caused by fatigue loads that are undetectable by X-ray

    A compact and reconfigurable silicon nitride time-bin entanglement circuit

    Get PDF
    Photonic chip based time-bin entanglement has attracted significant attention because of its potential for quantum communication and computation. Useful time-bin entanglement systems must be able to generate, manipulate and analyze entangled photons on a photonic chip for stable, scalable and reconfigurable operation. Here we report the first time-bin entanglement photonic chip that integrates time-bin generation, wavelength demultiplexing and entanglement analysis. A two-photon interference fringe with an 88.4% visibility is measured (without subtracting any noise), indicating the high performance of the chip. Our approach, based on a silicon nitride photonic circuit, which combines the low-loss characteristic of silica and tight integration features of silicon, paves the way for scalable real-world quantum information processors.Comment: 4 pages, 5 figure

    A high-throughput MAC protocol for wireless ad hoc networks

    Get PDF
    2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    A Unified Quantum NOT Gate

    Full text link
    We study the feasibility of implementing a quantum NOT gate (approximate) when the quantum state lies between two latitudes on the Bloch's sphere and present an analytical formula for the optimized 1-to-MM quantum NOT gate. Our result generalizes previous results concerning quantum NOT gate for a quantum state distributed uniformly on the whole Bloch sphere as well as the phase covariant quantum state. We have also shown that such 1-to-MM optimized NOT gate can be implemented using a sequential generation scheme via matrix product states (MPS)

    Clustering of Nck by a 12-residue Tir phosphopeptide is sufficient to trigger localized actin assembly

    Get PDF
    Enteropathogenic Escherichia coli (EPEC) translocates effector proteins into mammalian cells to promote reorganization of the cytoskeleton into filamentous actin pedestals. One effector, Tir, is a transmembrane receptor for the bacterial surface adhesin intimin, and intimin binding by the extracellular domain of Tir is required for actin assembly. The cytoplasmic NH2 terminus of Tir interacts with focal adhesion proteins, and its tyrosine-phosphorylated COOH terminus binds Nck, a host adaptor protein critical for pedestal formation. To define the minimal requirements for EPEC-mediated actin assembly, Tir derivatives were expressed in mammalian cells in the absence of all other EPEC components. Replacement of the NH2 terminus of Tir with a viral membrane-targeting sequence promoted efficient surface expression of a COOH-terminal Tir fragment. Artificial clustering of this fusion protein revealed that the COOH terminus of Tir, by itself, is sufficient to initiate a complete signaling cascade leading to pedestal formation. Consistent with this finding, clustering of Nck by a 12-residue Tir phosphopeptide triggered actin tail formation in Xenopus egg extracts
    corecore