914 research outputs found

    Alternative fuels : how can aviation cross the "Valley of Death"

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    Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2008.Leaf 260 blank.Includes bibliographical references.Aviation has used petroleum-derived fuels for over 100 years. With the rapidly rising price of oil and concerns about supply, the military and the commercial airlines are fostering the development of an alternative aviation fuel industry. In the U.S., coal, oil shale and biomass offer great promise as alternatives to petroleum for the production of aviation fuels. For the alternative fuel to be viable, the fuel must be price competitive, offer environmental benefits compared to petroleum, and must be qualified and certified for use in aviation. This thesis explores the barriers and risks associated with the technology adoption life cycle for alternative aviation fuels as viewed through the lenses of the technology developer, the early adopter, the early majority user, and the financial community. The challenges related to crossing the "Valley of Death" between technology development and deployment, and bridging the "Chasm" between the early adopters and the early majority of users are explored and a series of evaluation frameworks, tools, models, and recommendations are presented. The suggestions and recommendations provide potential actions that the military and the civil aviation sector could implement to reduce the risks and barriers for an alternative aviation fuel industry to commence and be sustainable both financially and environmentally.by William E. Harrison, III.M.B.A

    High dose, fast delivery magnesium sulphate in a 3-year-old acute severe asthmatic

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    Acute severe asthma when respiratory failure is imminent is not addressed in world asthma guidelines. Intravenous magnesium sulphate, salbutamol and aminophylline all have advocates but what order, speed of delivery or dosage is left up to the individual physician treating the patient. A child in respiratory failure was given a large, fast dose of intravenous magnesium sulphate before intravenous salbutamol which relaxed bronchial smooth muscle immediately and tracheal intubation and lung ventilation was avoided. Justification for this treatment is discussed

    Enhanced DNA Sensing via Catalytic Aggregation of Gold Nanoparticles

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    A catalytic colorimetric detection scheme that incorporates a DNA-based hybridization chain reaction into gold nanoparticles was designed and tested. While direct aggregation forms an inter-particle linkagefrom only one target DNA strand, catalytic aggregation forms multiple linkages from a single target DNA strand. Gold nanoparticles were functionalized with thiol-modified DNA strands capable of undergoing hybridization chain reactions. The changes in their absorption spectra were measured at different times and target concentrations and compared against direct aggregation. Catalytic aggregation showed a multifold increase in sensitivity at low target concentrations when compared to direct aggregation. Gelelectrophoresis was performed to compare DNA hybridization reactions in catalytic and direct aggregation schemes, and the product formation was confirmed in the catalytic aggregation scheme at low levels of target concentrations. The catalytic aggregation scheme also showed high target specificity. This application of a DNA reaction network to gold nanoparticle-based colorimetric detection enables highly-sensitive, field-deployable, colorimetric readout systems capable of detecting a variety of biomolecules

    Recent Cases

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    Constitutional Law -- Newsperson\u27s Privilege - The First Amendment Guarantee of a Free Press Protects Against Compelled Disclosure of a Journalist\u27s Exercise of Editorial Control and Judgment Plaintiff, a former army officer who had achieved national prominence by claiming that his superiors ignored his reports of atrocities by American forces in Vietnam,\u27 brought a libel suit against defendant television producer, reporter, and network for broadcasting a program that cast doubt upon plaintiff\u27s allegations. Contending that defendant did not present available information corroborating plaintiff\u27s claims, plaintiff sought discovery of the producer\u27s beliefs, opinions, intent, and conclusions in preparing the program. Alan William Duncan ===================== Income Taxation--Alternative Tax--In Computing Alternative Tax Under Section 1201 of the Internal Revenue Code Taxpayer May Not Deduct from Net Long-Term Capital Gain That Portion of Capital Gain Required To Be Set Aside Permanently for Charitable Organizations Decedent\u27s will required taxpayer estate to distribute to specified charitable organizations a specific portion, of net long-term capital gain realized upon the sale of any securities included in the residue of the estate.\u27 In calculating the alternative tax\u27 on the capital gains realized by the estate in 1967 and 1968, taxpayer deducted from capital gains the amounts required to be set aside for charities.: The Internal Revenue Service disallowed the taxpayer\u27s computation method, contending that a deduction for charitable set asides and payments was not allowable under section 1201. Elton Gregory Snowden ========================= Income Taxation-Corporate Reorganization-Stock Received Under Contingent Payment Plan Is Subject to Imputed Interest Provisions of Section 483 of the Internal Revenue Code Decedent\u27s will required taxpayer estate to distribute to specified charitable organizations a specific portion, of net long-term cap-ital gain realized upon the sale of any securities included in the residue of the estate.\u27 In calculating the alternative tax\u27 on the capital gains realized by the estate in 1967 and 1968, taxpayer deducted from capital gains the amounts required to be set aside for charities. Joseph W. Gibbs ==================== Torts-Independent Contractors-Employer Is Liable for Tortious Conduct of His Financially Irresponsible Independent Contractor All rules affecting the master-servant relationship derive from the historic legal principle that employers are liable for the tortious conduct of their employees occurring in the course of employment. Respondeat superior, which imputes employee negligence to the employer, is not premised on fault. Instead, because the employer has the right to select, control, and dismiss employees\u27 and because he is assumed to be in a better financial position to respond to judgments, the employer is held vicariously liable for tortious acts of his employees within the scope of employment. William Arthur Holb

    Atomic Force Microscopy of DNA Self-Assembled Nanostructures for Device Applications

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    DNA nanotechnology, which relies on Watson-Crick hybridization, is a versatile selfassembly process whereby a variety of complex nanostructures can be fabricated with sublithographic features.[1] Adopting this technology, 1012 identical devices can be synthesized to have hundreds of components with 1nm resolution. Example nanostructures include: 1) DNA motifs [2], 2) two-dimensional DNA crystals [3], and DNA origami [4]. Currently, this technology is being adopted towards electronic, optical, and opto-electronic devices.[5

    Kinetics of DNA and RNA Hybridization in Serum and Serum-SDS

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    Cancer is recognized as a serious health challenge both in the United States and throughout the world. While early detection and diagnosis of cancer leads to decreased mortality rates, current screening methods require significant time and costly equipment. Recently, increased levels of certain micro-ribonucleic acids (miRNAs) in the blood have been linked to the presence of cancer. While blood-based biomarkers have been used for years in cancer detection, studies analyzing trace amounts of miRNAs in blood and serum samples are just the beginning. Recent developments in deoxyribonucleic acid (DNA) nanotechnology and DNA computing have shown that it is possible to construct nucleic-acid-based chemical networks that accept miRNAs as inputs, perform Boolean logic functions on those inputs, and generate as an output a large number of DNA strands that can be readily detected. Since miRNAs occur in blood in low abundance, these networks would allow for amplification without using polymerase chain reaction. In this study, we report initial progress in the development of a DNA-based cross-catalytic network engineered to amplify specific cancer-related miRNAs. Subcomponents of the DNA network were tested individually, and their operation in serum, as well as a mixture of serum with sodium dodecyl sulfate, is demonstrated. Preliminary simulations of the full cross-catalytic network indicate successful operation

    Multiscaffold DNA Origami Nanoparticle Waveguides

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    DNA origami templated self-assembly has shown its potential in creating rationally designed nanophotonic devices in a parallel and repeatable manner. In this investigation, we employ a multiscaffold DNA origami approach to fabricate linear waveguides of 10 nm diameter gold nanoparticles. This approach provides independent control over nanoparticle separation and spatial arrangement. The waveguides were characterized using atomic force microscopy and far-field polarization spectroscopy. This work provides a path toward large-scale plasmonic circuitry
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